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- 1. TechTalk Q&A
- 1. Can you supply me with some companies who might supply PVC powder coating / powder coating products? Especially for use in dishwasher racks. Thank you!10.06.16More
Usually, PVC coating of dishwasher racks is performed by the major appliance manufacturer who is making the dishwasher. This product has been coated by fluidized bed methods for many years. However, very few people are doing it. I hope this answers your question.
- 2. "Does Powder Coating Net deal with delivering powders other than paints, epoxies, etc., to durable products, for example, powdered sugar to a food product, or powdered adhesive to a moving paper web?"10.06.16More
"Powder application equipment has been used in many "non-finishing" applications. I know of several instances such as: talc on rubber sheet, seasoning on food products, etc. The problem with these applications is getting the equipment suppliers interested in designing a specialized system for these "unusual" applications. Since the market for these systems is small, they normally cannot recapture the up-front engineering costs. However, a specialized engineering firm, such as ours, has been used to develop these applications under the control of the actual end user."
- 3. "Can you comment on the practice of applying iron phosphate (Bonderite 1030) over galvanized steel (G90) and then coating w/ TGIC Polyester powder 2mils thick. Specifically, what would the Q-panels look like after 1,000 hours salt spray with regard to adhesion, creep from scribe mark, corrosion."10.06.16More
Normally a zinc phosphate, not an iron phosphate, would be applied over a G90 substrate to achieve 1000 hours of salt spray resistance. Iron phosphate probably won't provide as high a salt spray resistance (i.e. 650+ hours). The TGIC powder would provide excellent weatherability for outdoor applications but won't effect the salt spray resistance on a scribed panel.
If, in fact you are using this substrate, pretreatment, and powder combination, then you would probably have more than 1/8 inch creepage and possibly some loss of adhesion after 1000 hours of salt spray exposure. Be aware that zinc phosphate has some waste water pollution considerations that are very different than iron phosphate. However, if 1000 hours of salt spray resistance is a requirement for your product, then you have little choice."
- 4. "Is there any solvent or method to remove screws that have been powder coated? The powder coat adhesion is so good that I keep stripping the screw heads."10.06.16More
"Because of powder coating's high resistance to solvent, finding one to break this bond may be difficult. You can try to cut the coating in the area of the screw head before turning the screw.
I would suggest that your supplier install the stainless screws after coating, so that they can be easily removed by you. I know they won't match in color, but stainless looks great uncoated."
- 5. "I have an aluminum sand cast housing and need to know what the correct process is for applying powder coating. We also use a chromate conversion coating on the unpainted surfaces for corrosion protection. I have heard 2 different stories of which coating to apply first (powder coat then chromate and vice-versa) Please provide any information as to what is the correct procedure for this process. Thank you."10.06.16More
"Always chromate before you powder coat if you want the corrosion protection under the powder coating surface. This technology will offer 5000 hours of salt spray protection."
- 6. "I am having problems with the charging efficiency of a powder formulation. Could it be due to the type of filler I am using? Is there any way to improve it with some kind of additive or pigment?. Thank you very much for your advice."10.06.16More
"It is not unusual for powder coating formulations to have different charging characteristics. These charging characteristics can be affected by particle size, filler materials, pigments, resins, etc. The proper balance between charging and formulation is normally empirically developed. I would look to the triboelectric series to determine if your filler more readily accepts a positive charge when frictionally charged by teflon. This is a necessary step even when using corona guns. All guns have teflon internal parts that can impose a positive charge on some powder formulations. If this is the case, then this tribo charge will reduce the effect of the negative corona charge by the same amount and therefore affect the total charge on the powder particle. In these cases it would be best to use a positive charging corona gun for the application."
- 7. "How do I get powder paint to stick to the edges of laser cut mild steel products, other than manually removing the scale before going to paint? "10.06.16More
"Laser cut parts have an inorganic soil (oxide) that is produced along the cut edge. This oxide can be removed by mechanical means (i.e. wire brush, sanding, blasting, etc.) or chemically (pickling). A "time saver" automatic sanding machine can remove the oxide very effectively, without manual intervention. Chemically etching with phosphoric or citrus acid (i.e. pickling) can remove this oxide from the part. This process can also be done automatically."
- 8. "Who publishes a quality-control standard specification for powder coating on CRS? We have a flat metal part that is 0.120 inches thick that is punched with 12 0.1" D holes. The powder form fuzzy balls in the holes. How do we coat the holes with an even layer? "10.06.16More
"There is no individual quality standard for powder coating Cold Rolled Steel. Most people set the QC standards to match their customer expectations and the end use of the product being coated. For instance, if your product sees outdoor exposure, then you may want to use an ASTM a standard for salt spray and UV resistance.
The fuzzy balls you see are probable lint or dust particles that have contaminated the powder. First check to see if these disappear during the curing of the powder. If not, then sieve all your powder (including the virgin material) using a 100 mesh screen to remove any contamination. If the fuzzy balls persist, then the contaminants are airborne and an isolated and E. V. controlled spray area is recommended."
- 9. "Our company would like to use a powder coating as a chemical agent resistant coating. We realize that epoxy powder coats are excellent interior CARC paints, but our company needs an exterior CARC paint. We have considered using a textured hybrid to attain the necessary UV, CARC, and low gloss which is necessary for camouflage vehicles. Do you have any suggestions?"10.06.16More
"You are on the right track to use a hybrid coating. But your application may allow you to use an pure epoxy which will loose gloss and chalk when exposed for prolonged periods to UV light. If this loss of gloss and increased chalking is unimportant when compared to the greater chemical resistance of epoxies, then you should stick with your first choice."
- 10. "I currently spray 0.75 mil of an inorganic zinc powder with a potassium silicate liquid onto wheel abraded steel plate that is rolled horizontally through the paint booth at 14 ft a minute. The zinc particles are between 6 and 8 microns. I was wondering if this application can be done using a dry powder? I have also heard of a flame coating system. Would this be a possibility and do you have more information on it?"10.06.16More
"All the equipment used in the powder coating industry is not made to spray powdered metals. Powdered metals will short the gun's charging system and wear the feed system in a short time. Sorry, but you will have to go to another industry to find equipment to be used with these materials."
- 11. "I am looking for an alternative to plugging tapped holes prior to powder coating and eliminating this step. I have considered tapping after coating, using self tapping screws and 'over sizing' the tapped hole to compensate for the coating thickness. Each of these has their own inherent problems. What is the common practice in the industry? Thanks."10.06.16More
"You have mentioned both corrective actions for tapped holes. Masking with plugs or post machining after coating. There are no other alternatives that can be employed on a production basis."
- 12. "We utilize a primer/enamel coating system to protect a tractor trailer which is used for transport purposes. These trailers have to be inspected for structural and weld defects such as cracks, stress induced defects, etc. My question is: "Is powder coating a viable candidate to use on a transport trailer and would it lend itself to structural examination better than a standard paint system which masks the defects. Also, does powder coating lend itself spot repair? If powder coating does not fit this application, can you point me in a different direction? Thank you."10.06.16More
"Powder coatings cannot be easily applied to tractor trailers since the curing process requires the part (in this case a trailer) to be oven baked at 325 degree F for 30 minutes. That may cause irreparable harm to rubber tires, oil seals, brake linings, etc. Further, powder coatings would not be any better in exposing cracks or stress related defects. Spot repair using liquid paints is not uncommon with powder coated products.
Although powder coating can be applied using flame spray equipment, this will not bring you closer to your goal of having a coating that can be easier to inspect."
- 13. "Are there any information packets available to send to clients letting them know the benefits of powdercoating? We fabricate custom ornamental iron, most of it is outside, gates, rails, etc. We recommend powder coating to our clients and would like to give them this information."10.06.16More
" There is a full color informational brochure available from the Powder Coating Institute, Alexandria, VA. Call them and they will be happy to fulfill your request."
- 14. "I would like to find out about powder coating non-metallic objects such as ceramics. Are there any technical publications on this subject?10.06.16More
"There is a technical publication called Powder Coating; The Complete Finisher's Handbook that is available through this web site. Click here for more info."
- 15. "Can wood; i.e., shells for drum sets be powder coated ?"10.06.16More
"The only wood products that have been successfully powder coated have been low moisture content wood products (i.e. MDO, pegboard, etc.) New technologies like UV curable coatings are being developed as we speak. Even these applications are best used on low moisture content wood products. Any wood products that must move or are moisture sensitive, should be tested prior to commitment of capital funds for equipment."
- 16. "I am after a technical explanation with regards to powder coating galvanized sheet steel. What I require is a technical explanation on the adhesion process. We are to submit this explanation to an engineer in the middle east to assist us in winning a contract."10.06.16More
"Powder coating will adhere to paintable grades of galvanized steel. These grades are known by their proprietary names such as "galvannealed steel", or "paint grip steel". Hot dipped galvanized steel will not provide a surface that is able to be powder coated. The powder will adhere to the galvanized steel but often the galvanized coating will fail from the steel substrate. Zinc phosphate is the normal pretreatment used in conjunction with powder coating galvannealed steels."
- 17. "How does the powder coating process affect the material properties of cast ductile iron? I understand that during the process of powder coating the temperature reaches up to 400 degrees F. Does this cause the material properties of cast ductile iron to become brittle?"10.06.16More
"The cure temperature of 400 F has only one effect on ductile iron...the release of entrapped gasses. The cast ductile iron does not become brittle since the part is at temperature for a relatively short time (15 to 30 minutes). Furthermore, higher temperatures are required to cause problems with Ductile or any other cast iron."
- 18. "I am looking for a powder that when cured has a rubber texture similar to plastic dip coatings. The purpose for the coating is sound deadening on seating products for upholstery furniture. Have any suggestions?"10.06.16More
"You are looking for a thermoplastic powder coating. These coatings will re-melt under heat conditions and are very soft to the touch. They are available in various formulations (PVC, polyethylene, etc.) and should be selected based upon the properties you need."
- 19. "I am searching for manufacturers of UV curable powder clear coating materials."10.06.16More
"There are 78 producers of powder coating materials in North America. But not all of them have UV curable materials. The Powder Coating Institute (703) 684-1771 has a current listing of their members who formulate powder coatings."
- 20. "We are a German producer of steel laboratory furniture. At the moment we are looking for an alternative to our presently used epoxy powder because of its poor UV-stability. Unfortunately the most used powders (epoxy, mixed epoxy/polyester/polyester or polyurethane powders) do either have a good UV-stability or a more or less acceptable chemical resistance. Do anybody know a powder which combines both characteristics, or a supplier for this powder in Germany? Note: We are not interested in a further supplier offering standard materials as mentioned above."10.06.16More
"You have listed all the materials that apply (except for acrylics which are very UV stable but have lower chemical resistance than pure epoxy). Most people select a powder coating that best meets all their requirements with the least tradeoffs. However, some tradeoffs are unavoidable. In your case UV exposure vs. chemical resistance. Select the coating that has the most important feature you need. Often we can't get all that we want in one coating. It is then that a two coat process can be helpful. In this case a chemical resistant base coat with a UV resistant top coat. That may be your best solution."
- 21. "I have an application where 2 metal surfaces are separated by ~.045 inch. This application is subjected to an environment which causes water accumulation in the gap. The gap is oriented such that gravity tends to "pull" the water out but because of surface tension the water remains in the gap. After the water accumulates the application can see cold temperatures which causes the water to freeze and lock the parts together. Is there a surface treatment that would act as a wick and draw the water from the gap? The coating would have to be less than .025 inch thick."10.06.16More
"In our industry a good pretreament system will provide a surface that is "water break free". This means water will sheet from the surface and not bead or form in droplets. If that is your desired effect, then I suggest that you investigate any pretreatment chemical supplier and ask for a cleaner chemistry that is compatible to your substrate and soil load."
- 22. "One of our customers is requiring a peel texture on an aluminum part that measures approx. 6" x 11". The part has cutouts, holes and inserts installed. The problem is that the peel texture is not consistent across the surface of the part. Sometimes the texture is flooded towards the middle of the part and sometimes it is flooded toward the edges. We have had several different powder coat applicators attempt to consistently apply both TCI and Tiger Drylak powders unsuccessfully. In your opinion, should it be possible to obtain a very consistent texture on a part as I have described? I would appreciate a quick response! "10.06.16More
"Surface texture consistency is a direct result of consistent film thickness. I see no reason that a consistent texture can't be applied to the part you describe. Be sure to control your film thickness to ensure a consistent texture."
- 23. "I'm looking for a powder that can easily be applied (using a hand-held applicator) to objects in order to dull their finish for 3D imaging using an optical imaging system. The powder would be removed after imaging. The powder should be a light color and should stick well enough to the surface to form a thin, even, opaque layer, but it should be possible to wipe it off after imaging. Ideally there would be no solvent involved so the operator would not have to take special precautions about ventilation etc."10.06.16More
"Applying an uncured powder coating should work for this job. The spray apparatus costs approximately $4000.00 and must be used in a ventilated spray booth ($10,000 depending upon size) for safety reasons. The uncured powder can be wiped or blown-off with compressed air after you have done your imaging. The spray booth would be helpful in supporting the blow-off operation. Airborne powder can be combustible in the right concentration, necessitating an approved spray booth for safety."
- 24. "We wish to post paint products. These involve thin and thick material sections (metal) as well as a plastic part. Are there any new developments in low temp cure materials and systems that meet automotive 'underhood' specs and salt spray specifications."10.06.16More
"There are many low cure temp. (250 degrees F) powders currently on the market. Determining which one will meet your specific requirements is a little more difficult. To determine which one will work for you we need your actual performance and appearance requirements. Then we can write a formal specification to solicit quotations from the various powder material formulators."
- 25. "Is there an industry standard for the disposal of used powder coatings, mostly fines and color contaminated powders (TGIC, polyester, hybrid, and epoxy)?"10.06.16More
"No there isn't. Since most powder coatings are considered non-hazardous materials they are normally disposed of as "landfill" materials in accordance with local ordinances. This may mean that your carting company may require you to melt the powder first to create a solid block. Check with your disposal company for pertinent information."
- 26. "We have a prospect looking to locate a manufacturing facility in our area who needs a company to do the powder coating for them. Can you supply me with a list of companies in Mississippi, Alabama, or the surrounding states who do powder coating? Your help would be greatly appreciated."10.06.16More
"Contact the Powder Coating Institute (703) 684-1771 and ask for their Custom Coaters Directory. It provides member companies by state who provide powder coating services."
- 27. "I am a student and I am working on a project about electrostatic painting. As long as plastics are not conductive I need to know how to make a plastics conductive in order to finish it with an electrostatic painting method. Specifically, I am looking for ways to make a polyamide 6 type plastic conductive."10.06.16More
"Plastics are prepared for electrostatic coating in two ways. One is to apply a conductive primer to the surface (Rans-Prep) and then spray it with the electrostatic gun as normal. The second method is to preheat the nonconductive part to 100 degrees F, of higher if the plastic can take the heat, and then spray the part using the electrostatic gun as normal. The preheating of the part works in two ways; one is thermal attraction, the other is the substrate takes on some conductive properties when it is preheated."
- 28. "We have been involved in the onsite application of thermoplastic powders for the last 3 years. To date we are aware of three powders, EAA, EMAA and Thermoxy. Are there others available? How can we contact the suppliers?"10.06.16More
"The best source for site-applied thermoplastic materials is Plastic Flame Coat (PFS). They are located in Texas and sell both the equipment and the materials."
- 29. "How does one control the particle size of powder coatings? Thank you."10.06.16More
"The particle size of powder coatings can be controlled using sieves. The screen size used in the sieve will allow you to separate powder particles as you require."
- 30. "How does powder coating compare to zinc plating in terms of salt spray and application cost?"10.06.16More
"Powder Coating is an organic coating that will never achieve the salt spray resistance of zinc plating, an inorganic material. It’s like comparing paint (powder) to metal (plating). Application costs all favor powder coating, which is much cheaper to purchase and apply. Further, powder coatings do not have any environmental problems, normally associated with plating. This further reduces the overall cost of applying powder coatings. It comes down to price vs. performance…plating costs more but provides better corrosion resistance than powder coating. Powder coating can achieve salt spray resistance of up to 1000 hours over galvanized substrates and 500 hours over mild steel."
- 31. "How can I remove a powdercoat finish from the interior and exterior of an aluminum part. Are checmical removal processes available. High heat is not desired due to the possibility of anealing the aluminum. Abrasive methods would likely not be able to remove the coating from the interior surfaces."10.06.16More
"There are both hot and cold immersion stripping systems available for this process. Hot strippers can use chemicals, sand, or salts. The hot strippers will not anneal the aluminum like burn-off ovens. Cold strippers use only chemicals. If chemicals are used, be sure to follow all the instructions, take the appropriate safety precautions, and dispose of them properly."
- 32. "I know that the zinc layer of both hot dip galvannealed and electro-galvannealed may contain holes. Ref, Galvatech '95 Conf. Proceedings page 345. How is it that a coating with this type of irregularity does not exhibit outgassing? Do you know the origin of the gasses in hot dip galvanized: steel substrate, zinc layer or boundary layers? What is the size and the distribution in the paint of the air bubbles."10.06.16More
"The galvanneal process releases the entrapped gasses. Most likely the zinc layer is the origin of the gasses since steel substrates do not exhibit similar problems. The bubble density is proportional to the amount of gas entrapped in the zinc surface; more importantly the distribution of surface defects is also related to the physical characteristics of the paint; i.e., viscosity."
- 33. "We are currently investigating various methods of removing un-cured powder from our load bars as a form of rack cleaning. One idea that was presented was to use an on-line vacuum system to suck the paint off before entering our cure oven. Is this possible? Is anyone in the industry doing this? If so, what are the drawbacks?"10.06.16More
"We recommend you use this vacuum method only as a last resort. It would be difficult to implement and would most likely disturb some of the powder and drop it onto the parts below. Look to correct the problem using the following methodology:
1.Locate your load bars outside of the booth (i.e. above the conveyor slot) Use a "Top of rail to top of part distance" of at least 36 inches.
2.Improve the ground on the part to ensure that it is the most appealing target for the powder being sprayed.
3.Remove sources of air currents that may be allowing the powder to migrate onto the load bars, if they are already located outside the booth."
- 34. "Is there any solution to the rigid behavior of our low gloss color powder coating? Our coating failed after a several tests of twisting and bending over a 3 mm bar. I would like to find powder suppliers that could help us solve this problem. Thank you all."10.06.16More
"There are many "flat" or "matte" powder coatings that have low gloss and good mechanical characteristics. In fact, the two are not related. Locate any of the 75 formulators of powder coatings in the North American market who have overseas manufacturing and sales outlets. A list of companies can be provided by the Powder Coating Institute, located in Alexandria, VA."
- 35. "We use powder to coat capacitors and we have an intermittent problem with holes forming in the the coating at the ends of the capacitors. Do you have any suggestions on how to solve this problem?"10.06.16More
"Pinholes are sometimes caused by outgassing in unusually thick powder coatings. Since you are fluid bed dipping these parts, I would venture to say that this is your problem. Corrective action can be as follows:
1. Tighter control of film thickness during the coating process.
2. Modification in powder formulation to increase the flow time. This will allow the outgassing to occur while the powder is still soft enough to flow over the pinholes prior to full cure."
- 36. "We are trying to go to a powder coat on an extruded aluminum piece. We are coating it with a textured metallic aluminum colored finish. The problem we are having is the finish has a waviness to it ...it goes from a light shade to a darker shade throughout the part. Also the texturing is not consistent and is blotchy. Are these problems normal."10.06.16More
"It sounds as though the applied film thickness is varying widely. Employ a more controllable spraying technique for better results."
- 37. "I would like to know about mixing our own powder colors. I can't seem to find any info on this subject. I would like to know prices for turnkey systems, area needed, or just general info."10.06.16More
"The cost to make powder coatings is price prohibited for most end users. Powders are not "mixed" like paint in a hardware store. Powder coatings are formulated by polymer chemists. The formula components are weighed and placed into dry blenders, then extruded (melt mixed), then chill-rolled, then flaked, then ground, then classified for size, and then packaged. This process is not easily performed and can have problems with consistency from batch to batch. We suggest that you purchase your powder from any of the 75 formulators in the USA."
- 38. "I am interested in recycling powder coating. Can you give me some information?"10.06.16More
"Powder is normally disposed as non-hazardous landfill waste. The industry has not yet addressed recycling this material, since it is so easy to dispose. I know that the recycle subject is on a the agenda, but it is not going to be addressed by our industry until disposal problems become more acute."
- 39. "I'm interested in suggestions and concerns regarding touch-up work in the field for parts installed in an industrial environment. How well do powder coated parts take to touch-up paints? What types of paints can and should be used to touch-up scratches or chips in the coated surface?"10.06.16More
"Powder coated products are readily touched-up in the field. The specific paint to use should be recommended by your powder formulator who will select one that is compatible to the powder coating used."
- 40. "We are presently applying a hybrid powder to a clear zinc (electroplated) cold roll steel. We're experiencing a problem with paint adhesion on the finished product. Our zinc plating sub contractor, provides a bright clear (slightly blue) zinc finish and seals with a thin hexavalent chrome dip.(6 sec.) Our facility then applies powder to specification, bake @ 350 deg. F for > 15 min. Bake temperatures of 375 to 400 deg. F have a higher failure rate. Note: per customer specification, most product is powder coated on one side only! Opposite side must be conductive, offer salt spray protection >10 hours, and be cosmetically appealing. Recent efforts: zinc sub contractor, switched the chrome bath from hexavalent to trivalent and the powder supplier is presently working on a low bake ( 300 deg. F @ >10 min.) Questions: 1. What is the cause, is it the zinc, chrome, powder ! 2.Is there a solution, please note customer spec. 3.Are our "Recent change and projects" a step in the right direction.4. Is there a test method and/or equipment available, which can measure a surface potential adhesion prior to powder application."10.06.16More
"Adhesion problems exist for two primary reasons; one is cleanliness of the surface prior to powder coating. Two is proper cure. If the part is not clean after the zinc plating or the powder is under cured after powder coating, then the film will not adhere properly to the substrate. People powder coat over zinc plated parts all the time, therefore, the problem is not related to the zinc, chrome, or the powder.
The solution is to properly handle the parts after zinc plating to reduce soils (hand prints, etc.) and/or fully clean the parts prior to powder coating them. Secondarily, all parts must be fully cured to adhere the substrate. I can’t tell you if these "recent" efforts make sense without seeing the parts. There is an ASTM test method that will check adhesion after the coating has been cured. Prior to powder coating the only thing you can check is the surface cleanliness (water break free & white towel testing)."
- 41. "I am looking for a powder that when cured has a rubber texture similar to plastic dip coatings. The purpose for this coating is sound deadening on seating products for upholstry furniture. Have any suggestions?"10.06.16More
"You are looking for a themoplastic powder coating. These coatings will remelt under heat conditions and are very soft to the touch. They are available in various formulations (PVC, polyethylene, etc.) and should be selected based upon the properties you need."
- 42. "I have just had sheets of 9" by 48" flat perforated steel, 16 gauge with 5/16" diameter holes powder coated by a local company. My intent was to get a high dielectric strength using Corvel 1700 epoxy series powder that gives 800 to 1000 volts per mil. The problem was the 5/16" holes did not get a good coating on the inner part or around the edge of the hole which causes an electrical breakdown at the high voltage (2000 to 5000 volts) and low current needed for the application . The build seems to be about 5 mills on the flat surface. How many mils can be put on with normal coating? Can the sheets be coated again without stripping off the first coat to get a film build of 10 to 15mils or more? Any suggestion on how to proceed would be very helpful. Thank You."10.06.16More
"Most powder coatings can be applied using standard electrostatic spray techniques up to 10 mils. At that point the powder coating will be "self limiting" because the part ground is no longer sensed by the charged powder particles. Preheating the part has been an effective way to overcome this problem in high film build applications.
The sheets can be recoated without stripping the previous coats if some precautions are taken. First the surface must be clean. Second the part must be adequately grounded (less than one megohm resistance). Finally the total number of coats cannot exceed two if the part is fully cured between coats without risking coating degradation from overbaking.
The problems you are having with the holes is called edge coverage. This coating characteristic is formulated into the powder coating and controls the flow and build of the powder on all edges. This combined with the Faraday problem in 5/16" diameter holes will prevent full coverage in this critical area. I suggest that you check the coating spec sheet to ensure that the coating has the edge coverage characteristics you need and preheat the part prior to coating to overcome the Faraday problems."
- 43. "We are a job shop metal finisher with three automatic zimc plating lines, two automatic e-coat lines, and some other services.We are in the process of adding a 9000 square foot powder coating line within a building addition. Our customers are very excited and are starting to ask about pricing. We are getting many inquiries for quotation/pricing. I have a very good handle of what my costs will be, but I do not know what the current acceptable profit margins are for powder coating. Can you give me some idea as to what some pricing per mil square foot is right now based on a few standard powder types? I want to make sure that I am not going in to the market too strong or too weak. FYI: Our system has a ten stage washer with all RO water, two cleaning stages, many counterflow rinses, iron phosphate, chrome sealer, and micro-filtration of the cleaning stages. We will have a Nordson Cyclo-Kinetic booth and a spray to waste booth. The powder and the powder application equipment will be in an atmospherically controlled room. We will be able to do clear coat over our zinc plating, as well as use our e-coats as primers. Your help is greatly appreciated."10.06.16More
"There are no published profit margins for the powder coating industry. The adage of "charge what the market can bear" does apply to our industry as with any other industry. Good luck in selecting a price that your customer is willing to pay for the services that you provide. Most job shops are including other value-added services, such as assembly and packaging, to provide a one stop service approach to their customers. This ensures they are not readily shopped by other custom coaters competing for the same business. A rolled-up cost including other value added services can offer you some protection from a commodity marketplace."
- 44. "I would like to try powder coating over 316 Stainless Steel and need to specify a pretreatment and powdercoat topcoat. The item will be used in a marine environment, and the powdercoat will be used only as a barrier coating since the item will not be subject to heavy wear/abrasion. Is powder coating suitable for this type material? Or is it better to leave the material uncoated or coated with conventional means (paint)?"10.06.16More
"Some of our clients apply a powder coating to stainless steel products. They do not expect the powder coating to provide any mechanical or corrosion properties since the stainless steel performs well enough for their application. The sole purpose of the powder coating is to camouflage the part to better blend into the surrounding environment. For instance green for suburban locations and gray for city locations. You should decide what the powder coating is going to achieve on your product. A barrier coat doesn’t make sense since the stainless steel will perform well uncoated. If you want to camouflage your part, choose a coating that will meet that objective, either powder or liquid. Pretreatment of the substrate is very important for stainless steel. Choose Silane, or other adhesion promoter, to be applied prior to powder coating or you powder will not adhere to the stainless steel. Sometimes, grit basting can perform the same function."
- 45. "I have a tow hitch on my landcruiser that is powder coated. The car is only 4 months old and there are 2 rust spots already forming in the weld areas. The dealer has agreed to take a hitch and have it painted for me and replace the one that is rusting. I am concerned that if they only have it primed and painted conventionally that I may get an inferior product back. Should I insist on powder coating? Is powder coating far superior to prime and paint? What are the advantages of powder coating? If powder coating is superior, why am I getting rust so soon? Is there anything regarding powder coating that I should ask for to get a premium job?"10.06.16More
"We have first hand experience with trailer hitch coating since we have a high profile client who is in that business. The failure you are experiencing is very common on that product. The reasons for it are poor pretreatment of the part prior to powder coating. The manufacturer uses hot rolled steels and does not treat these substrates or the weld areas properly prior to coating the part. That means there are inorganic soils on the surface that cause loss of adhesion and corrosion problems with the powder coating. Anyhow, the best fix for your situation is to have the dealer sandblast the hitch down to bear "white metal" and powder coat the part again. This will remove all inorganic soils and defective coatings. Using an iron phoshate pretreatment would also help provide for a better job. The powder coating (a TGIC Polyester is best for this application) will provide a superior finish to any liquid coating, giving you a hitch that will outlast the vehicle."
- 46. "Please provide suppliers of materials and equipment for low temp powder coating applications."10.06.16More
"There are no major distinctions for suppliers in low temperature applications over normal powder coating application equipment and materials."
- 47. "We are a rolling door manufacturer. When we powdercoat our bottom bars (2"x2"x1/8" steel angle) we need to be able to mark them to identify them as they come out of the oven. Is their a special marker that we can use? Tagging is out because of time involved plus there is no place to hook the tag on the bar."10.06.16More
"There are no markers that will survive the coating and curing process. Tags work best. But if you don’t want to use them, you can try stamping the numbers into the part itself. Maybe if you tell me why you need to identify these parts, I can be more helpful."
- 48. "We coat a product that is mainly made up of a cast steel material. We use a three stage wash with iron phosphate cleaner in the first stage, rinse then a seal coat. The question I have is, since production levels of this product are rising we see a increase in TDS in our first stage of the wash. Normal city water is at 180 ppm TDS and bath parameters are to be within or under 480 ppm. What appears to be happening is the TDS is rising for some unknown reason . We think it has something to do with the make-up of the cast steel or contaminents it brings into the wash.. I think maybe I answered my own question, but could you confirm this for me please?"10.06.16More
"It is not unusual for TDS to rise in washer tanks. This value represents the "Total Dissolved Solids" within a tank solution. These solids are in your water when you first charge your tank and they are added when they are removed from the parts that are cleaned by the system. This is expected and normal. When you achieve your limit on TDS just dump your tank. If dumping becomes to frequent, then consider inline filtration to remove the particulate. By the way, TDS should be checked in your rinse stages. Adjust your overflow rate to compensate for TDS levels in the rinse stages."
- 49. "Need information relative to achievable surface finishes using epoxy powder coats on alluminum components. Typical parts are 2' x 4' hatch covers. We are required to supply near automotive finishes on these parts and also required to utilize epoxy based powder due to chemical resistance, etc. Orange peel has been an ongoing problem."10.06.16More
"Powder Coatings can be formulated to achieve different surface appearances. There are "Smoothness Standards" available from the Powder Coating Institute (703) 684-1770 that depict smoothness in a range of 1 to 10. Select the smoothness you want and notify your powder supplier. He will formulate an epoxy to meet your finishing requirements. Be prepared to pay more for the coating and have more sag rejects. Smoothness is a function of flow during cure and can cause sagging on heavily coated parts. Consider using a "Coating Specification" to accurately describe all your powder coating properties. We write these specs as a service to our clients. Consider the problems that you can incur without a clearly written specification: Part rejects, high coating costs, unsatisfied customers, equipment downtime, etc. Contact Powder Coating Consultants at (800) 97-POWDER for assistance in this matter."
- 50. "I am restoring a 1926 Nash Roadster. The wheels are 21 inch steel disks manufactured by Budd Michelin. Another auto restorer suggested having the wheels powder coated. I am not acquainted with this process. My questions are: Can I have the wheels powder coated in black gloss and then paint over the black on the outside with the body paint color (probably lacquer )to finish the wheels to the original two color paint scheme? The wheels have been dip tank cleaned to bare metal and then treated with phosphoric acid to prevent rusting. What preparation would be needed for powder coating? Thanks."10.06.16More
"Liquid coatings can be applied over powder coatings to provide a two-toned finish. Selection of the powder and liquid must be done with great care to ensure compatibility. Go to a custom coater for help in selecting the right process and coating materials. The Powder Coating Institute has a list of Custom Coaters by State (703) 684-1770."
- 51. "What sort of touch-up options are currently available for items that have been powder coated?"10.06.16More
"Liquid touch-up paint, compatible with the powder formulation, can be applied directly over the powder coated surface. The liquid paint is available in spray cans, pens, and in bulk."
- 52. "Is there an industry standard for the disposal of used powder coatings, mostly fines and color contaminated powders (TGIC, Polyester, Hybred and Epoxy)?"10.06.16More
"No there isn't. Since most powder coatings are considered nonhazardous materials they are normally disposed of as "landfill" materials in accordance with local ordinaces. This may mean that your carting company may require you to melt the powder first to create a solid block. Check with your disposal company for pertinent information."
- 53. "I would like to know what exactly is powder coating and how is it used?"10.06.16More
"Powder coatings are mostly organic coatings that provide superior properties to liquid paints. The application of powder coating is common-place. If you need a painted surface, then powder coatings may work for you."
- 54. "We are looking for producers of equipment suitable for a fusion bonded pipe coating application. It must include: gas heater, abrasive blast-cleaning, a spray booth to provide electrostatic application to the surface of the heated pipe, etc."10.06.16More
"There are many system houses that can accommodate your request (over 50 companies). Call the Powder Coating Institute or Products Finishing Magazine. Both of these sources have booklets listing companies that sell these systems."
- 55. "As far as I know, the electrostatic painting of a plastic requires that the paint and plastic have opposite electrical charges. I want to know if and how I can electrostatically charge a plastic?"10.06.16More
"Since both the paint and plastic are dielectrics, electrostatic charging can be used. However, the results will be dubious since the charges may cancel each other out. This would result in no powder being deposited on the surface. Normally powder coating is applied to grounded conductive products (metal) using electrostatically charged powder particles. Powder coating plastic has been performed in the past using thermal attraction; the plastic part is preheated and powder is sprayed using typical electrostatic techniques. The heat enhances the adhesion of the coating particles on the plastic surface."
- 56. "I am looking for a supplier of N-11 nylon for my business of re-coating vibrator drums for the printing industry."10.06.16More
"Nylon 11 coatings are available from Dupont, Thermoclad, Rilsan, and Alf Autochem."
- 57. "We are currently assessing a powder coating operation that burns off excess paint on the hangers after every application. Is there a hanger that is non-conducting and would not have to be burned off after the powder coating process?"10.06.16More
"All hangers must conduct earth ground for the electrostatic attraction of the powder spray activity to work correctly and safely. Therefore, at least the hanger contact points at the conveyor and at the parts must be conductive to ground. These are areas where the build-up of powder must be cleaned. Non conductive hangers will not work in this process and pose a serious safety risk."
- 58. "As a powder coater for the past three years, I have had great success with metal products. Now I would like to ask if there is technology available to powder coat glass and ceramics. As a plumber for many years, I have already powder coated faucets for my wife, and would like to explore the powder coating of porcelain closets and lavatories. Thank you for your time and consideration."10.06.16More
"Powder coatings have been successfully applied to glass bottles and decorative pieces (vases, containers, etc.). No one to my knowledge has tried to powder coat toilets. In may be because the powder finish would not be as good as the original porcelain coating. Many toilet manufactures provide their products in lots of different color finishes that are more durable than powder coating. If you want to try coating toilets, preheat the item to gain thermal attraction of the powder. Then cure them as normal. Good luck."
- 59. "I am looking for high temperature powders; something that can withstand 1000 deg. for engine exhaust system parts. I have seen exhaust headers and pipes on street rods and snowmobiles that have a high temp silver coating. Is this a wet or powder coat and who manufactures these coatings?"10.06.16More
"H. B. Fuller has a complete line of organic powder coatings that can withstand 1000 degree F temperatures. The silver coating you are describing doesn’t ring a bell. This coating may have a metalic base and/or may not be a powder."
- 60. "I bought a new house in February and by August, the windows of the house which have a powder coating paint, vanished in areas right to the metal. The home builder sent someone in here and all they did was just spray paint with paint from a spray can. Now the spray paint is beginning to peel from the windows and chip. What needs to be done to correct this problem and how much do you estimate it will cost."10.06.16More
"Sounds like you have a surface contamination problem that wasn’t addressed by the window manufacturer. As long as this contaminant remains on the window surface, no paint (powder or liquid) will stick. Clean this area using a solvent and scuff the surface with sandpaper to expose bright new metal. Topcoat with a urethane liquid paint and hope for the best. The window manufacturer should provide some insight as to which paint they recommend for field repairs."
- 61. "Electrostatic powder coating is a known explosion/fire risk and powder coating systems typically have an explosion/fire suppression system. What type of detectors (thermal, pressure, flame, etc.) are the best type of detectors on these systems? What is the best source of information about suppression systems for coating operations?"10.06.16More
"Many powder coating recovery booths are designed without containment devices and, therefore, eliminate the potential for explosion. These powder booth designs are called Cartridge Booths. On those systems where containment devices are used in the recovery system design, explosion vents will release the energy quickly without damage to the surrounding area. All powder coating systems that employ the use of automatic guns must be protected by fire detection systems that must interrupt the booth exhaust and spray operation within 0.5 seconds of ignition. Those systems with contained recovery systems must also have a segregation damper in the ductwork that is activated by the fire detection system preventing the fire from entering the containment device. Since organic powder coatings do not support flame unless they are airborne within specific limits, their safety record is unsurpassed in the finishing field.
Suppression systems are used if the normal design precautions are not used. This is rarely the case since the cost of suppression systems is quite expensive. If a suppression system is used, it can be activated by sensing thermal, optical, or pressure conditions."
- 62. "We are specifying a system to powder coat parts of varying size and material thickness: primarily structural steel fabrications (bars, angles, rod, etc.) from .125" through .500" thick. Individual parts weigh from 1 to 2000 lb, the majority weighing 10-30 lb. Coating thicknesses will be either 4 mil or 10 mil. Will the cure time and/or preheat (dry-off) time vary enough to reduce overall system throughput?"10.06.16More
"Without a doubt, yes! The "bring-up" time; that is, the time required to raise the metal's temperature to the cure temperature, is dependent upon the specific heat capacity of the metal and the part's mass. For example, the heavier the part, the longer the "bring-up" time. All powder coatings specify their cure times at metal temperature. Note: these specified cure times do not include the bring-up time."
- 63. " We finish a cast aluminum piece of with a polyester powder coating. We then pour an epoxy or polyurethane (not powder coating) into a 1/8th" cavity. Once cured and exposed to thermal expansion and contraction, the clear coat separates from the powder coated piece. We are looking for something that might help the clear coat bond/adhere to the polyester powder-coated piece. Also, is there a "binder" or "primer" that will help the adhesion between the two? Any help would be most appreciated."10.06.16More
"Your problem is two-fold; one mechanical, one chemical. First, there is the difference in mass between the two coatings and the effect on thermal attraction. For instance, the liquid epoxy/polyurethane is 1/8 inch thick in an area where the polyester powder coating is probably 0.002 inches thick. Beyond the two different rates of expansion because of the two different materials, the mass difference will allow one material to expand faster/slower than the other. This is a design problem. You have to choose two materials that will expand or contract at the same rate.
The second problem is the chemical intercoat adhesion between the two materials. Your powder formulator can help by adjusting the formulation of the polyester powder coating to more readily accept the epoxy/polyurethane.
"Binders" or primers will not solve your problem and will most likely cause problems with the color of the base coat and the clarity of the clear coat. The process you describe has been successfully implemented by many manufacturers using a base coat powder with clear top coat powder on aluminum."
- 64. "Have you heard of anyone doing powder in a Hot Barrel tumble operation?"10.06.16More
"No, we haven't. It would seem that the finish would be damaged since the applied powder coating requires some time (approx. 15 minutes) to cure at approximately 400 degrees F. If the product is tumbled during this time the finish would be damaged."
- 65. "We are establishing a small batch powder coat operation. I need a complete "course" on the chemistry of pretreatment in a five or six tank immersion system; i.e., cleaners, iron phosphate, pH control, analysis of rinse water, non-chromic sealer, pH control. In other words we know nothing about powder coating and the learning curve could be a challenge. Can you steer us in the direction of good information?"10.06.16More
"Standard daily tests for pretreatment are called titrations. Titration procedures are dependent upon the actual chemistry used in the cleaning system. Since each pretreatment chemistry is proprietary, all titration procedures are unique and are developed by the pretreatment chemical supplier.
Frequency of the titration checks depends upon product throughput, product quality, and soil load. When checking to ensure that solutions are within controls, the rule of thumb is that no intervention (adjustment of chemicals) should be required for two out of three checks.
The other powder coating system checks depend upon many things. For instance the type of equipment, the quality requirements, customer specifications, etc. Things, like oven temperatures, powder output, booth performance, powder usage, etc. can be helpful in ensuring that the system is operating properly and doesn't require maintenance.
The Powder Coating Handbook describes test procedures used to verify product quality. Furthermore, we have written many articles dedicated to this topic. We have also assisted many clients in determining what testing should be performed on their products. For further info, contact us for help or buy the Powder Coating Handbook as described in our reference section."
- 66. "What type of paint system would work best for the inside of a tank that holds a 10% chlorine solution ( 90% water). I think either a polyester or a urethane powder would be best."10.06.16More
" We recommend using a thermoplastic coating like Nylon or polyethylene. These are functional materials that are normally used to coat the insides of tanks. If you must use a thermoset coating material then look closely at epoxy. It has the best chemical resistance and its low UV tolerance is of no consequence inside a tank."
- 67. "Do regulatory agencies such as the EPA and OSHA publish specific guidelines for treatment and/or disposal of wastewater used in connection with a phosphatizing spray wash and pretreatment operation? This question would naturally include the organic soils, mill oils, rust inhibitors, coolants, lubricants, die release and drawing compounds."10.06.16More
"The EPA establishes national limits for discharge. These may differ dramatically from your local PTOW authority. You must check with them for your actual limits of wastewater discharge. Contact your local DEP for local air and water discharge limits.
OSHA requirements are usually covered by the MSDS information for precautions on handling the chemicals. We recommend contacting your local OSHA agent for particulars."
- 68. "Are there any products available that can be used as a "filler" to hide imperfections or to fill seams in CRS (Cold Rolled Steel) prior to the powder coat process? We are presently using a polyester TGIC powder coat with a cure schedule of 400 degrees for ten minutes."10.06.16More
"Standard fillers (i.e. Bondo, etc.) will not work under powder coating, since they will outgas during cure of the powder. I do not know of any metal based fillers available on the market that will give you what you want. There are some fillers that have metal in them, but they still have resins and hardeners that can outgas."
- 69. "I have been working with a nylon based plastic with powder primers. Epoxy and acrylic urethane based powder coating appear to have great adhesion and chip resistance. The problem is moisture. Nylon will absorb small amounts of moisture over time. If I pre-bake the substrate (for as little as 5 min.@250F) the appearance is equal to powder primed steel. If I don't pre-bake and the moisture content gets above a certain level, the result is mirco-porousity and popping across the entire surface. Since pre-bake is an extra step with an added cost, for many customers, this may not be an option. Is it possible for powder formulations to be adjusted for flow and cure? The ideal situation might be for the powder to stay "open" long enough so that the moisture has a chance to leave the substrate (during the powder bake) and not interfere with the powder during the cure phase."10.06.16More
"The powder coating material you seek is referred to as an anti-outgassing formulation. This material will stay in a liquid state for a longer period of time when compared to standard powder coatings. During this liquid state, the part is allowed to outgas through the powder coating and then harden as the coating approaches final cure strength.
This material is more prone to sags (runs) since it stays softer for longer periods of time. Whether or not all your moisture escapes through the coating while the powder is in its liquid state can be proven by test."
- 70. "I am looking into building and testing an electrostatic fluidizing bed for our parts. Can you help me in obtaining information on how to charge the air/powder? More specifically, where can I purchase and receive information on how to properly install high voltage electrode equipment?"10.06.16More
"Electrostatic fluidized beds are available from Nordson Corporation, Amherst Ohio. They are the only company who currently sells this technology.
Building your own won't necessarily save you much money and if not done correctly, they can be very dangerous. Just think of it, you'll have to build an electrostatic generator, electrode, fluidizing hopper, product transport system, and containment exhaust system.
We strongly recommend that you purchase a system that meets all the codes and is inherently safe against fire and explosion."
- 71. "I am having trouble keeping paint on the lower leg of my outboard motor. This is a small, aluminum, 15-horse Evinrude, which stays in Lake Ontario from May to October each year. The difficulty seems to be twofold, with lack of paint adhesion being one problem, and of course corrosion another. I have tried a lot of different things, and last year went through what I had thought was going to be a very good preparation. I sandblasted to bare metal, prepped the aluminum with a 2-step (probably chromium) etch, applied zinc chromate primer. All this was followed by the outboard manufacturer's lacquer, and finally a TBT (tributyl tin) top coat for antifouling. All paints were applied from spray cans, and strictly according to the manufacturer's recommendations. This held up well for a couple of months, but still failed. However, it worked much better than just painting over a wire-brushed surface. Interestingly, I also did the controls the same way at the same time, with the same coatings (except for the antifouling top coat), and the controls are fine after a year. Of course, they are not submerged for 6 months at a time. The primary purpose in this case is protection, not aesthetics. Can you make any recommendations? I had also considered stray electrolytic or galvanic currents as a factor. I have two sacrificial teardrop zincs bolted to the anticavitation plate of the motor. Since it is electric start, it is well-connected via 10 AWG wire to the 12V battery ground. The bronze thru-hulls and external lead keel ballast are also "bonded" into the 12V ground. The zincs are fastened to the motor by stainless steel bolts. I applied a light film of lithium grease to the area between the zincs and the aluminum of the anticavitation plate, which is unpainted. The zincs did show some oxidation after 1 season, but no massive erosion. It seems that corrosion is now only a small part of the problem. I do use a regular, automotive-grade battery charger occasionally, so I am sure that there is some AC leakage to ground during charging. I do keep the charging to a minimum, since the outboard is alternator-equipped. At this point, I am thinking that the coating (in my case, lacquer) is not impervious to continuous submersion. It seems that deeper down the lower unit, the worse the failure of the paint. Since the top area sloshes in and out of the water, it is not continuously submerged. In any event, the prep and paint, combined with the addition of the zinc anodes, had by far the best results. I am thinking that epoxy or polyester powdercoat would allow less water migration. I know that when preparing fiberglass hulls, the standard is to paint them with an epoxy water barrier before applying antifouling bottom paint. This reduces the occurrence of osmotic blisters in the polyester laminate. Also, when installing and removing the motor in the Spring and Fall (the motor is mounted in a "well" inside the lazarette), there is always some paint chipping off the edges of the prop and anticavitation plate that exposes bare aluminum. Hopefully powdercoating would resist the chipping a little better. I have also considered having the drive unit plated, but even nickel plating would probably require a copper base plating, which would react with the aluminum substrate underwater, essentially creating a self-destructing battery. Do you think epoxy powdercoat is the way to go? Maybe two coats are better than one."10.06.16More
"An epoxy powder coating would be the ideal paint for your application. A zinc-rich epoxy primer coating would be even better. Two coats would be better but the top coat should be polyester for its UV stability (of which epoxy has none). UV stability would resist chalking on sunlight exposed surfaces.
You will have to completely disassemble the entire lower unit of the outboard motor before powder coating. Cure temperatures of 350 to 400 degrees F will cook all bearings, seals, o-rings, etc. For this reason, powder coating your outboard motor would not be my first choice.
Some manufacturers looked at powder coating for their in-plant paint systems, but decided to go another way. Using a recommended liquid paint from the manufacturer may be the easiest. Let's face it you are in a fresh water environment which is not as bad as saltwater. Powder coating may just be too much hassle for the slightly improved benefits.
By the way, after you disassemble the outboard, every part needs to be scrupulously cleaned and neutralized using distilled water. Aluminum substrates require a chromic conversion coating (alodine) if you want the best corrosion performance. This type of finish is used by the outdoor furniture market where 20 year warrantees are the norm."
- 72. "I sell decorative out door lighting poles & fixtures. A city I am currently dealing with has requested the poles to be anodized. I need specific reasons why powder coating would be a better finish."10.06.16More
"Powder coating is not better than anodizing. They are completely different. Powder coating is an organic finish while anodizing is inorganic. Anodizing would be harder, more corrosion resistant, more durable, and would last longer than powder coating. It's like comparing plastic to metal; no contest.
Your argument to the city should revolve around: "Better color selection, less cost, opaque vs. translucent coating, and more environmentally friendly". Leave "better" out of the discussion."
- 73. "Can you tell me the effect that the powder coating process has on the heat treatment of aluminum, specifically 6061 T-6"10.06.16More
"To our knowledge powder coating has absolutely no effect on heat treated aluminum. The cure temperatures are usually under 400 degrees F (typically 325 to 375 degrees F) and should not anneal the 6061 T-6 material.
Furthermore, exposure time at these temperatures is 10 to 25 minutes. The higher the temperature the lower the exposure time to cure the power coating."
- 74. "Are there different grades or standards which I would need to specify to my powder coaters. We are ISO9002 and this is a pre-requisite when ordering ANYTHING!"10.06.16More
"All powder coatings should be purchased using performance specifications to ensure consistency of the coatings from batch to batch. Furthermore, powder coatings are formulated to achieve stated appearance, mechanical, corrosion, and environmental properties. If you don't state your expectations and your system's operational parameters, how would the powder coating formulator know what to deliver to you?
This is why you need a specification to reliably order your powder coating. You can contact us for help in writing such a specification that will ensure proper and consistent performance of the powder coating on your product."
- 75. "We are a custom sign manufacturer. We have a project where we will set an 8' dia. x .25" aluminum disk into a floor that receives moderate foot traffic. Would a clear powdercoat finish hold up in this environment? If so, what would be the best specification? Can the powdercoat be removed (dipped) if we have to refinish the piece in the future?"10.06.16More
"A clear powder coating can achieve a 2-3H pencil hardness and have great abrasion resistance. These features are important to your specific application. However, this doesn't mean that powder coatings will be impervious to scratching caused by dirt and sand trapped on footwear.
The best way to look at this application is to compare powder coatings to other acceptable finishes. Powder will be superior to liquid paints but not as good as anodizing or plating. You can get clear anodizing on aluminum but you can't get clear plating for steel. If your alternatives for powder are liquid paints, then powder coatings will give you better performance.
However, if your alternative is clear anodizing on aluminum, then powder coatings won't give you the same performance."
- 76. I restore vintage motorcycles. I just had an AJS frame powdercoated by a local custom shop, at a cost of over $500. It was my first experience with powdercoating, and may be my last.
The problem appears to be durability---or lack of it. The finish dents easily, there are spots where I can peel it off with my fingernail, andother spots where it looks like rust is coming through.
When I went back to the shop to discuss these issues with the owner, he showed no real concern, and instead shoved "testimonial" letters from other customers at me to read.
Unfortunately, I had already done too much reassembly (bearings, sleeves, etc) to have anything else done with it.
My real concern, before I try this again is: Did the shop screw up, or did I pick the wrong color, or is powdercoating not as durable as I was led to believe?
I am very careful when reassembling my machines and yet I have made several blemishes on this frame already."10.06.16More
"It sounds like the painter screwed up. Powder coatings are formulated to provide a variety of properties, in most cases much superior to liquid finishes. However, if the part was not cleaned properly before coating or the part was not fully cured after coating, then these properties will be compromised. Your vendor should evaluate the part and the resultant damage to assess if the properties that are inherent in the formulation he used are realized. If not, he should strip the part and re-coat it.
If he feels that the properties have been realized, then he chose the wrong formulation (nothing to do with color)."
- 77. "Can you powder coat on SMC? If so, then I would like info on the process."10.06.16More
"There are two ways to powder coat SMC (Sheet Molded Compounds). One is in-mold coating when the part is made. The other is coating the part on a traditional system after it is made.
We have participated in projects that used both methods. If you are not the actual manufacturer of the parts then you would be interested in the second method. SMC products are cleaned and dried prior to being heated to approx. 250 degrees F. They are then sprayed with the choice of powder coating and cured using high intensity IR. It helps if the powder coating is low-cure."
- 78. "I have heard decorative paints are available in different colors as well as flourescence. Can we use flourescence on jewelry?"10.06.16More
"Yes, powder coatings of all varieties have been successfully used in jewelry applications."
- 79. "We have a situation where a boxed in wrought iron fence has been erected around a harbourside property. The fence has developed a white residue on the wrought iron section but not on the box section. From what we can find out, the box section was hot dipped galv. and the wrought iron was cold gal. primed prior to being powder coated. Is it possible that zinc oxide from the cold galv. primer has leached through the black powder coat, and if this is the case, what can we do about it?"10.06.16More
"It is certainly possible that the zinc primer is leaching through the powder coated surface, especially if there were pinholes in the powder coating caused by outgassing. This "white rust" is unsightly and may reduce the life of the product, although it is difficult to determine how much the life will be reduced. If you must eliminate this problem entirely, then you must strip all the coating and zinc from the surface and try again, using an alternate zinc preparation."
- 80. "Does aluminum have any cleaning standards/specs that have to be satisfied before applying the powder coating?"10.06.16More
"First, you must understand that the powder coating process has to provide a finish that is commensurate with your customers' expectations since the process can be tailored to meet a wide variety of finishing requirements. For this reason there are no "standard" pretreatments used in processing aluminum.
For instance, aluminum pretreatment systems can provide between 1000 - 5000 hours of salt spray and humidity protection. If you make fasteners that are used in the outdoor furniture industry, then the 5000 hour salt/humidity protection pretreatment system would apply. However, if you are making fasteners used in electronic cabinets, then 1000 hours of salt spray and humidity protection may be more applicable.
The costs for procuring, operating, and maintaining these two different pretreatment processes vary greatly between them. It would not be prudent or cost effective to implement a pretreatment process that does not satisfy your customers' expectations or would be excessive for the application. For us to provide a more specific answer, we would have to review your objectives firsthand."
- 81. "If I have a trellis powder coated and delivered to my project in 2 pieces and then welded together, due to its size, is it possible to field apply a powder coating to the welded areas?"10.06.16More
"Since the parts need to bake out at 305+ degrees, there is no way of performing powder coating in the field . There is a "flame coater" that sprays molten powder towards a surface, but this is used with thermoplastic coatings (i.e. PVC, Nylon, Polyethylene, etc.). An appropriate liquid touch-up paint can be used, but this material must be compatible with the powder coating basecoat. Check with your powder material supplier or the painter for an appropriate liquid touch-up material. You may want to scuff the surface before applying the liquid touch-up paint."
- 82. "We recently had a small fire. All cold roll steel parts have a light coating of rust. This is from fire extinguisher chemicals becoming air born and settling on the top surfaces of the material. My question is this, what should be used to prep the surfaces before powdercoat is applied?"10.06.16More
"You must remove all the rust prior to powder coating. Approved methods are: grit blasting, wire brushing, grinding, or sanding. Use the method that will provide you the surface texture you can live with. After removing the rust, pretreat and powder coat the parts as you normally would."
- 83. "We have been running into an adhesion problem on the edge of steel parts, approximately an 1/8" thick. The parts are laser cut using oxygen. I have heard that the problem stems from a layer of oxidation that develops as a result of the laser cut. Is this what I could be experiencing, and if so how can I cure it?"10.06.16More
"Your assessment of laser scale as the problem is correct. The use of oxygen gas during the laser cutting process will produce a scale (inorganic soil) along the edge of the cut. This soil will be an impediment to proper adhesion of the powder coating. To remove this soil you have three choices:
1. Change the cutting gas to nitrogen to eliminate the soil, but this will slow the cutting speed by two thirds.
2. Mechanically remove the soil using wire brushing, sanding, grinding, or grit blasting. Sanding can be performed in a "Time-Saver" machine with little effort.
3. Chemically remove the soil using an acid-etch chemical process called "pickling"."
- 84. "After reading through your FAQ's, I see that e-cap has been removed from the EPA's list of HAPs. I was wondering if e-cap is considered a VOC?"10.06.16More
"Currently (10/00), the EPA does not consider e-cap a VOC."
- 85. "We manufacture an ISO container chassis; the "trailer" that holds the shipping container unloaded from ships. Presently, we blast the fabricated parts and two main I beams, weld them together in a jig, apply a zinc-rich primer and urethane topcoat, then install axles, tires, wiring, etc. The steel frame is about 3000 pounds after welding. Is powdercoating a viable option, and would it be as resistant to corrosion?"10.06.16More
"Yes powder coating would dramatically improve your corrosion resistance and is well suited for your application. The automotive industry currently powdercoats a variety of products used in vehicle undercarriages.
Your part size and weight can easily be accommodated in a well designed powder coating process. We suggest you contact us for insight on how best to proceed with your investigation."
- 86. "I am looking for some information on the amount of reclaimed powder that can be reused in systems. I have a facility I work with that is sending out about twenty 55-gallon drums/month to a landfill. There is not a lot of weight involved, but the volume is a problem. I was under the impression that by increasing spray efficiency and mixing the small reclaimed particles with virgin, we would have almost no waste."10.06.16More
"Most powder coaters fuse their waste powder before disposing it. This process should be performed with caution. Always use a metal container (cardboard can catch fire) and do not try to fuse too much at any one time (one drum at a time).
By filling a drum with powder and placing it in a convection cure oven, the powder will fuse and melt down to approximately 15% to 25% of the original volume. You can then refill the drum with more powder and continue the process of melting until the drum is filled.
Since the weight of the powder isn't reduced (just the volume), the weight of the filled drum of fused powder will be quite heavy (approximately 4 times heavier). This method will allow your powder coater to reduce the volume of waste to less than 25% of the volume they currently dispose (i.e. less drums). Furthermore, the landfill will appreciate not having to deal with unfused waste powder, which can be quite messy."
- 87. "What would prevent or what would be a possible cause for a powder paint not to adhere to the surface of a steel tube?
Water soluble rust proofing has been applied to this tube. The pretreatment process has 5-stages including a phosphate wash. The steel tube isn't the only problem,
the painter is having problems with a pure aluminum also.
The painter says they haven't changed any processes and the tubes look just as they have for several years. The painter goes on to say that just over the past 6 months have they had any problems.The painter is also having problems paint thickness and has slowed down the conveyer so that the parts have a longer cure time. What can you tell me?"10.06.16More
"Loss of adhesion can happen as a result of several process issues. First, is the part clean? A five stage washer should clean most organic soils from the part if it is properly maintained. However, if you have inorganic soils on the part or the process is out of control, then the washer (no matter how many stages) is not doing the job.
Second, is the powder out of date or too old? As powder coatings reach their maximum shelf life (approximately 6 months) then the powder's properties can start to fail and result in loss of adhesion.
Thirdly, is the part fully cured? Performing a solvent cure test in accordance with PCI Test Procedure #8 should tell you if the part is fully cured. Uncured powder coatings can easily fail adhesion tests. The vendor's cure oven may not be operating properly, so just slowing the line speed down will not correct the problem. An oven profile should be performed on your part in a fully loaded oven to ensure that the part's metal temperature reaches the temperature specified by the powder supplier for the prescribed amount of time (dwell time or cure time)."
- 88. "The use of oxygen gas during the laser cutting process will produce a scale (inorganic soil) along the edge of the cut; changing the cutting gas to nitrogen to eliminate this soil is expensive. Will the change to shop air eliminate the scale along the edge of the cut?"10.06.16More
"No. Changing the gas to compressed air will not prevent the inorganic soil from forming on the metal surface since the compressed air will still have oxygen. If you want to stay with your existing process, then you must remove this soil before powder coating or painting. The recommended methods of removal are grit blast, sanding, wire brushing, or chemical etch (acid pickling)."
- 89. "We believe that we have unsatisfactory cyclone efficiency. I asked our equipment vendor about how much the micron filtration on our cartridge and final filters has to do with cyclone efficiency. His response was "very little to nothing". I was hoping to confirm this because I was always taught that the pressure in the cyclone depends on a variety of things, an important one being the filters."10.06.16More
"Cyclone efficiency is most effected by the powder particles' velocity and size. If your filters let more air pass through them because they are coarser, then the fan will pull more air volume through the system and the particulate velocity will go up. As the powder particle enters the cyclone at a higher velocity, the cyclonic action will have less influence allowing the powder to go directly into the scrap module. As you use more reclaim materials the particle sizes change (usually coarser). This would normally help the cyclone efficiency."
- 90. "Gentlemen, Some time ago I read an article by Nick Liberto that mentioned the possibility of 'water quenching' for cooldown after the bake/cure process. Where can I find some info./sources for this? It seems like it would be much faster than a forced cool air cooloff tunnel. I'd like to bring the parts down to near ambient as fast as possible to maximize throughput. Would the 'misting' leave water spots and or salt deposits?"
"Also, again with maximum throughput in mind is it possible to powder paint parts that are around 225deg. F (i.e. after they come out of pretreat-dryoff? My powder supplier recommends a part temp. no greater than 125-130deg. prior to paint application. We will be using a 'hybrid' black with low gloss/flat finish. Any help would be appreciated."10.06.16More
"For the record, my name is Nick Liberto and I'm president of Powder Coating Consultants."
"When I wrote that article, I was referring to custom designed water quenching equipment. Most system houses in our industry will be happy to quote you one. This method is certainly faster than forced air cool-down, but has some associated risks. For instance, water spots are a problem. However, these can be dealt with by treating the cooling water prior to spraying. There are sheeting agents, softeners, etc. that can be employed to correct this problem.
As far as the proper part temperature for powder coating, your powder supplier is correct in stating that the temperature should be between 125-130 degrees F. Hotter parts will tend to have higher film builds and may begin melting (or sintering) the powder as it is applied. Both of these issues can affect appearance and fit of the coated part. But if they don't, then have at it. Good luck!"
- 91. "I am looking for information on how to determine the type of equipment needed to add powder coating to our current services. Where could I find information on the amount of floor space, equipment needed, prices...etc. The largest thing to be coated would be a car chassis."10.06.16More
"We can help you determine your equipment needs and floor space requirements. We do NOT sell equipment, but can provide objective help. Otherwise you are on your own. We charge $750.00 per day for this service and it probably wouldn't take more than 2 to 5 days of our help. Call us at (800) 97-POWDER."
- 92. "How does poor quality rinse water or pretreatment cause accelerated corrosion?"10.06.16More
"Rinse water quality directly affects corrosion resistance in several ways. First, polluted rinse water will not sufficiently remove the soils or active chemistry from the previous working stage. If the product isn't full cleaned and neutralized, then the next working stage (i.e. iron phosphate, zinc phosphate, alodine, etc.) will not deposit evenly or in the correct amounts to prevent corrosion in the field.
For instance alkaline wash solutions normally precede acidic iron phosphate stages. If the rinse doesn't remove all the soils or neutralizes the surface, the pH of the iron phosphate will be difficult to control leading to poorly formed phosphate coverage. Secondly, rinse water in the final stage must passivate the surface to provide maximum corrosion resistance. This is performed with a slightly acidulated rinse solution (sometime called a sealer rinse). Lastly, all rinse water must be free of chlorides and other contaminants (i.e. CaCo, and salts). If your city or well water isn't up to par, then you will have contaminates (salts) under the coating that will eventually mix with moisture and lift the coating (blisters). This is the normal failure mechanism seen in corrosion failure and is the reason to buy a DI or RO water system for the final rinse."
- 93. "Is there an industry standard for powder coat colors?"10.06.16More
"Some powder suppliers use RAL numbers to describe their powder coating colors. Check with your suppliers to see if they support this technical standard for color identification."
- 94. "I'm applying both smooth and rough powder coated textures. Well, when I apply the rough texture it causes a lot of smoke in my oven. None of the other powders do this, just this one. Can you answer me why? Do you have any books that give out info all about powder coating?"10.06.16More
"Some powders have more by-products of cure than others, often resulting in smoke in the cure oven. You should check with your coating supplier to see if there are any by-products that you should be concerned with. If not, just proceed as normal.
There is a great book on powder coating: "Powder Coating - The Complete Finisher's Handbook". Click here for more info."
- 95. "I have been told that gloves should not be used with the powder coating process so that the operator remains grounded. If this is the case, what is the best method to ensure that the skin is protected when using powders containing isocyanurates?"10.06.16More
"Isocyanurates are not normally transmitted by way of skin contact. Inhalation is the only concern. However, if your painters have sensitive skin they can protect themselves by using conductive gloves supplied by the electrostatic gun supplier or grounded wrist/ankle straps."
- 96. "Is the shape of of the powder particles important? In what respect? Can it have an impact on the process or in its use?"10.06.16More
"The shape is not as important as the size distribution of the powder particles. Think of applying powder coating like building a stone wall. Smaller stones fill the gaps between the larger stones, leaving a smooth top surface to the wall."
- 97. "The local OSHA representative (who admits he is not fully versed on powder coating) insists that our powder coating booth (batch system with hand held gun) have an automated fire suppression system (i. e. sprinklers) on the front and back of filters. Does anyone know if this is accurate as it would appear to put the gun operator in harms way? "10.06.16More
"Fire suppression systems are normally required by your Fire Marshall authority and your insurance company. However, OSHA can suggest safety equipment also. A liquid paint system can have two sets of sprinklers (in booth and after the filters). However, powder coating systems normally have sprinklers in the booth only. The guidelines listed in NFPA #33 (National Fire Protection Association) are the recommendations employed by most governing agencies. However, local authorities can stipulate anything they want.
NFPA #33 states that the "spray area" must have an approved fire suppression system consisting of dry chemical, water sprinkler, etc. The "spray area" has often been interpreted to mean the spray booth, although the room containing the spray booth has also been considered the "spray area". You must comply with your local authority. Finally, sprinklers will not hurt the operator or the equipment. If they go off, you may have to buy new filters for the booth. "
- 98. " We are a small machine shop that does some work for the government. We work with some Mil Spec paints and primers. We just received a large order for some aluminum parts that will need to be painted. A friend suggested powder coating. Can I get powder coating supplies that will meet Mil Standards? The paint we use now is a Chemical Agent Resistant Coating (CARC) epoxy . If you know of such a product please let me know. "10.06.16More
"We know of no powder coating that meets your chemical resistance requirements. There are powder coatings that meet mil specs. The mil spec that comes to mind is MIL-C-24712A and Mil-C-24712A AMENDMENT 1. "
- 99. "We produce coating powders such as LDPE, HDPE, PP, NYLON. One of my customers is asking whether Nylon 6 or 66 can be electrostatically coated on metals used for automotive parts. If possible, what size particle is best suited for an electrostatic spray-coating system? "10.06.16More
"Electrostatic spray grade Nylon is normally ground to a particle size distribution of 20 to 40 microns. Larger particles are OK, but smaller particles are more difficult to pump and charge. Your customer may have to use a positive polarity corona charging powder gun. This is important since 99% of all powder coating guns are negative polarity. Past experience has proven that Nylon accepts a positive charge more readily. "
- 100. " I have some parts that I am considering to finish to with powder coating instead of with conventional paint. I have been told that powder coating might hide any cracks that occur during normal use of the part. Is it true that the powder coating will hide any hair line fractures that might occur after powder coating? "10.06.16More
"If these crack are truly "hairline" cracks and the powder coating has some excellent flexibility properties, then the coating should hide them. However, coating thickness and surface smoothness will play a role in how well these cracks are hidden. "
- 101. "Please comment upon the situation regarding the emission of E-Caprolactam in urethane-based powder coatings."10.06.16More
"E-cap has recently been removed form the HAPS list and therefore is no longer a concern for powder coaters."
- 102. "Is this an industry standard for torque testing and/or correlation to impact testing?"10.06.16More
"We know of no such correlation between impact and torque testing requirements. Although the forces of torque are similar to impact, there are several other powder coating functional properties that can be similar to torque. For instance, surface hardness (rated in pencil hardness), adhesion, abrasion resistance, mar resistance, and others can all have an effect on the coated surface when a fastener is torqued to a known standard."
- 103. "Please advise regarding possible pollution of premises leased/owned to a powder coating business. "10.06.16More
"Any industrial use of property can be subject to pollution. There is nothing specific to powder coating that can cause pollution, but some of the cleaning chemistries may have been disposed of improperly. You should have the site tested by an approved agency. "
- 104. "Problem ... powder coat paint is peeling away from the cut edges of our laser cut parts. Is there any way to remove the oxide coating from the laser cut edge besides using a 3M pad, wire brush, grinding, etc. we are considering using nitrogen as our laser assist gas, but this proves to be an expensive alternative."10.06.16More
"Changing the shielding gas will eliminate the oxide problem, but will slow your cutting speed by almost 50%. All the mechanical methods you mentioned will remove this oxide from your laser cuts. There are chemical methods available to remove this inorganic soil. Pickling is the term used to describe this chemical methodology that uses phosphoric acid or citric acid chemistries. The pickling process can be performed by either immersion (dip tank) or spray wash methods."
- 105. "Having an adherence problem on a 12" long 10GA HRPO steel formed channel. The raw material was cut to size using a laser cutting process. The adherence problem is restricted to the edges of the part only. The paint chips of. Any ideas, causes or solutions?
The powder coater is currently using an iron phosphate pretreatment in the wash system. Would increasing the concentration help?"10.06.16More
"The problem you are experiencing is caused by a scale left by the laser cutting system. Changing the shield gas can eliminate this problem, but will cause the laser to cut at 50% normal speed. You can remove this oxide using abrasion techniques (sanding, wire brushing, grinding, etc.) or using chemicals (pickling). You must remove this oxide to prevent the adhesion problems on laser cut edges.
A normal iron phosphate pretreatment system will not remove this laser scale! Pickling is the only chemical process that will remove this laser scale."
- 106. "We are investigating the process of powder clear-coat over a powder base coat system. Is anyone doing this in production currently? We are currently doing high gloss and metallic polyurethane powder. The application is outdoor lawn and garden equipment. "10.06.16More
"Yes, several companies are applying clear powder coatings over color powder coatings. The result is a high definition deep coating (high DOI). In fact, many outdoor furniture manufacturers do this on their specialty colors. The process is straight forward (base coat applied and partially cured then the clear coat is applied and fully cured). The base coat will accept the overbake of the clear coat without problem. "
- 107. "For a desktop application, what is the wearability of powder coating MDF as opposed to using a horizontal grade laminate? How do these products compare?"10.06.16More
"Powder coatings on MDF is purported to be as durable as laminates. These materials have been used on a variety of products including office furniture. This technology has been around since the late 1990's and does not yet have the track record of laminates. Therefore, actual life testing of these powder materials on MDF products has been limited to the laboratory. These laboratory tests have been successful. The suppliers of these powder coating materials have high hopes that manufacturers of MDF products (store fixtures, office furniture, etc.) will switch from laminates to powder for all their solid colors. We have not heard of any premature failures of these materials on MDF products to date. Actual product wearability properties are dependent upon the specific powder formulation and are available from the formulator of these materials."
- 108. "What is a good filler for use in filling around rivets and inserted hardware, to present a smooth blemish free surface after powder coating? "10.06.16More
"You can try Lab-Metal� from Alvin Products, Inc. This has been developed for use in powder coating operations and can withstand the heat for curing while providing the ground necessary for the electrostatic deposition of the coating powders."
- 109. "Are you aware of anyone who is looking for waste powder? Also, have you run into adherence issues with adhesives on textured (medium) powders? "10.06.16More
"We are aware of no company looking for "waste powder". However, there is a company (Surplus Powders) who will buy unused virgin overstocked materials.
As for your second question, adhesives do not stick well to textured powders because the labels normally just hit the points of the texture. Additionally, textured powders often have additives that form the texture and gloss that can prevent a good bond with adhesives. Look into changing the gloss level of the textured materials you use. Lower gloss powders can work better with your adhesives."
- 110. "We have had a very strange problem with one of our customers. The customer is powder coating scaffoldings for export. After coating the steel scaffolding and during stacking of the scaffolding frames, the frames slip one above another and the entire stack of 25 frames falls down. This has become a very serious problem bcause they have stopped their production due to this. They attribute this slipping phenomenon to the smoothness of the film. I have tried to change the formulation of my powder on order to reduce the gloss and cured film thickness but to no use. The same slipping phenomenon exists. The worst part is that the customer says that our competitor's powder does not give the slipping effect; hence we may lose a very good customer although our powder is of the highest quality."10.06.16More
"You should try a thermoplastic powder such as PVC. The slip characteristic of this material is poor. If you must use a thermoset powder, I suggest you try a textured material.
It may be unreasonable to stack 25 round tube scaffold frames on top of one another without it falling down. Your customer should be more interested in the mechanical and corrosion properties of the powder formula you provide.
- 111. "We received a large shipment of storage racks which were powder coated with green and yellow paint. They were stored outside for 4 weeks during times of heavy rain. The racks are now showing rust at the weld points and certain areas where the steel part meets another steel part. The manufacturer of the racks says that the rust is normal for the material being stored outside. Also the material has a great deal of shipping and scratching during the shipping / unloading process. My understanding of powder coated products was that it would prevent the very things I mentioned. Is there some sort of specification for powder coating that varies based on the application and what is reasonble for me to expect of the material that is powder coated? How do I know that the manufacturer did not have some sort of QC problem with their powder coat paint process? Are there consultants that can help? "10.06.16More
"It sounds as though there could be some process problems at your supplier's manufacturing facility. Powder coated steel products are used in extreme outdoor environments without corrosion problems. For this to occur you need to first select corrosion resistant steels. Next you must clean and pretreat them properly before coating. And finally, you must select and apply a powder coating that has the inherent properties to meet the fielded conditions.
It sounds as though your shelving supplier did not meet at least one of these criteria. Along with writing the answers to the Powder Coating Net's Tech Talk section, we are consultants to the powder coating industry. We are an objective technical resource to many clients who are using or specifying powder coatings. To get more information on our company and services, please go to our web site."
- 112. "I have recently redesigned a complete powder coating system and have since inherited the system forever and always. That being the case, I was concerned when the Environmental Technician informed me of the California code pertaining to the possible carcinogen found in epoxy type powder. We currently use PPG epoxy. What's the latest? Thanks very much!"10.06.16More
"You should check this problem with PPG to obtain an MSDS sheet. The only component that is "hazardous" which comes to mind is ecaperlactum. This additive to many powder formulations is currently on the EPA HAPS list, although I hear that is about to change. If this is the material that your local inspector is talking about, then be aware it is released in the oven during cure. Therefore, operator exposure shouldn't be a problem, unless your oven isn't properly exhausted. I repeat: CHECK WITH PPG TO ADDRESS THIS PROBLEM. They know their formulation and have the resources to address this situation."
- 113. "I am looking for the manufacturer of the special powder coating that Ford Motor Co. has released on their new cars this year. The manufacturer/distributor of this coating demonstrated this new product at a company I worked for in Eugene, Oregon approximately 1 year ago."
"I am a designer working on new product development and am VERY interested in finding this particular powder coating. Please point me in the right direction if you have any suggestions. Thanks for your time!"10.06.16More
"To my recollection, Ford is only using powder coatings for under hood and under carriage parts. Be that as it may, There are over 65 manufacturers of quality powder coatings in North America. Which specific one visited your company would be impossible to guess. Sorry we can't help you on this one."
- 114. "What is the fluidizing membrane made of? This membrane is inside the hopper and helps to keep the fluidizing homogeneous."10.06.16More
"The material is generically called "porous polyethylene". It is sometimes sold under the name of "Glass Rock". I encourage you to purchase this material from the company you bought your equipment from. They know what size and shape is required to fit your hopper. If you are trying to design your own hopper or fluidized bed, there is more to it than buying the membrane."
- 115. "Are there commercially viable processes either available or under development which may be used to powder coat phone housings injection molded from Polycarbonate ABS blended plastics? Plastic DTUL @66psi =265F?"10.06.16More
"Yes. Powder coating has been used on plastics that can withstand at least 250 degrees F. These plastic parts are preheated to at least 225 degrees F to attract the powder coating from electrostatic spray guns. The powder is then cured in an oven at 250 degrees F to provide the desired finish. A "low temperature cure" powder coating is used in this process. Sometimes IR ovens are used to preheat and cure the parts without fully heating the plastic substrate. The newer UV powder technologies are also used on plastic parts. In this case the parts are preheated and coated as previously described. The powder is then melted on the surface to flow the material using either convection or IR ovens (approximately 250 degrees F). Finally the powder is fully cured using UV technologies. Either of these methods can work on plastics or some wood products if they can withstand at least 250 degrees F. "
- 116. "I am looking to heat up an element using infrared light, Is there a powder coating that is flat and dark (so that it can absorb the heat) in color and that can withstand heat of up to 1000 F?"10.06.16More
"Yes. The powder material you are looking for using a dual resin system (epoxy and silicone). As the part is subjected to heat above 450 degrees F for a prolonged period of time the epoxy part of the formulation breaks down and is replaced by the silicone portion of the formulation. This material is used on exhaust systems and outdoor grills and is available in dark colors. This material can be cured using IR energy."
- 117. "We have been in the business of designing street furniture for outdoor advertising; anything from Bus Shelters to internet Kiosks. We tend to use mainly aluminum extrusions, mild and structural steel. We are reviewing our paint specifications, and cannot agree as to what is the right thickness of powder coating we should be using. We are looking for a quality finish, which will live in the harsh street environment, subject to air borne pollution, UV etc. We also install our equipment in coastal areas. All contracts are for a minimum of 15 years so we are "longing for longevity". Can some one advise us or point us in the right direction?"10.06.16More
"Coating life is affected by many more things than just coating thickness, especially powder coating life. Coating thickness is recommended by the formulator of the coating and is normally specified in a range (i.e. 2 to 4 mils). This coating thickness range will determine the best situation for all the coating properties to be fully achieved. Thicker and thinner coatings will not perform as well as the ideal range specified for the particular coating you have selected. Coating life is directly affected by the selected coating properties, substrate selection, pretreatment of the substrate, and application process control. You can have the best coating, but if you do not select an appropriate substrate, clean and pretreat that substrate properly, or apply the coating with a process that is out of control, the coating will still fail prematurely. Careful selection of the powder coating, correct cleaning and pretreatment of the substrate, and properly controlling the powder coating process is the only way for you to achieve your desired results."
- 118. "Our powdercoating department has a problem. In the past we have hung product on our line in the afternoon in preparation for the next day. Now all of a sudden our maintenance foreman has decided that we can only wash what we are painting that day. We have always known that we can't do this with our bare metal products but we were able to do it with galvanized, primered, and aluminum parts. We never had any problems before. Are there any concerns that you can see with us pre-loading the line because our production rate has fallen off considerably since we stopped. The longest these parts sit is 16 hours as we never pre-load the line over the weekend. I would appreciate an actual expert opinion?"10.06.16More
"Nothing good can happen to a part that has already been cleaned and has not been coated and cured. It is always a good idea to store in-process products before they are cleaned and after the coated parts are cured. Not much can go bad with parts in these two conditions. Once a product has been cleaned but not coated and cured it can become contaminated by airborne dirt, inadvertent hand prints, or even flash-rust or oxidization. There is nothing that will happen to the chemicals on the product after pretreatment if left on the conveyor overnight. Using a staggered shift is the best way to eliminate wait times between the process steps and to ensure that cleaned parts are not left on the conveyor line overnight. This would be preferable to leaving the parts on the conveyor overnight."
- 119. "We are having some problems when coating cast aluminum parts. These cast parts are usually decorative parts of handrail or fence systems. The problem with peeling is due to corrosion that starts under the casting. There are no peeling problems with the aluminum extrusions, just the castings that are on them. So far, these problems are only occurring in waterfront areas. I'm sure the salty air is the main cause, but are there any ideas how to coat these parts better? "10.06.16More
"Corrosion under the powder coating will cause the film to peel off the substrate. This corrosion is the direct result of improper cleaning and pretreatment of the raw parts before powder coating. If these casting are made from aluminum, then you will have aluminum oxide and salts on the surface that must be removed prior to coating. The approved method for pretreating powder coated aluminum parts that will be used in high corrosive outdoor environments (i.e. salt air) is as follows:
1. Clean the surface (organic soils) using and alkaline cleaner.
2. Rinse the surface.
3. Remove the inorganic (aluminum oxide) soils using a deoxidizer cleaner.
5. Apply a chromate conversion coating (Alodine).
In lieu of this aqueous method of pretreatment you can grit blast the surface to a white metal profile to remove all organic and inorganic soils before applying the powder coating. However, this methodology will not provide enhanced corrosion resistance as the Alodine system described above. "
- 120. "I just had a motorcycle rim powdercoated. Upon completion there were numerous small bubbles and specks on the part. He (the powdercoater) would not redo the part. His reply was that he didn't know what I expected and that some (out) gassing was normal. He basically threw me out of his shop and told me he didn't need my business. I just wanted the part to look nice for my money. Is that normal? "10.06.16More
"No it is not normal. Gassing can be caused by numerous things, but I suspect that improper cleaning caused it here. The specks can be dirt or other powders that may have been left in the gun or feed system causing cross-contamination. Go get your money back!"
- 121. "What is the best out-gassing primer to use? I have a zinc casting that is about a quarter of an inch thick and is used in laboratory work. This part gets a smooth epoxy powder coat finish. We have tried pre-baking and several out-gassing primers. We have varied the coating thicknesS. Is zinc or iron phosphate the best pretreatment for this part?
I've been scratching my head for about five years trying to figure this one out. We are currently using a wet primer. Out of 160 parts, about 40 end up with defective finishes. I hope you can help us. Thanks."10.06.16More
"Zinc die castings are notorious for out-gassing when subjected to the temperatures required to cure powder coatings. The amount of out-gassing depends upon the metallurgical composition, casting vents, chill locations, speed of "pour", etc.
Sometimes preheating the part can reduce the problem, but not always. Out-gassing primers are becoming popular to reduce this problem. You have tried both of these approaches with some success.
Next you should ask your powder supplier for an out-gassing topcoat powder formula. During cure, these materials stay in the liquid state for a prolonged period of time. This allows any gas to escape. The escaping gas breaches the coating and forms holes. However because the coating has been formulated to stay in a liquid phase longer, the coating flows back over these holes to provide a smooth surface.
If the casting has a large amount of entrapped gasses, then this approach will provide limited benefits if all the gas has not fully escaped because eventually the coating will have to gel. It may be that you will not ever entirely eliminate this problem, however using all the recommended methods may reduce your defect rates to acceptable levels"
- 122. "What precautions should be taken by an operator engaged in the powder coating process? Is it necessary to wear breathing protection and if so, what type is recommended? Does powder coat (in any form) contain isocyanates? Are there any other hazards that someone undertaking powder coating should be aware of?"10.06.16More
"Material Safety Data Sheets (MSDS) are available for all powder coatings sold in North America. These sheets describe the hazards associated with a particular coating powder. They will also describe any necessary safety precautions that should be taken while working with the pertinent coating powder. For each coating powder that you may come in contact with, read its MSDS and follow the precautions contained therein to protect yourself from any health risks."
- 123. "I recently purchased a paint spray booth. I paid an extra $1600 to it have powder coated. While I was putting it together, I noticed some runs in the coating. Also when I tried to wipe off some paint splatter with thinner, the coating turned soft.
I was under the impression that powder coating was very strong and tough. Was I wrong or is this correct? I am trying to determine if I paid for something I did not get. I would appreciate any information you can provide as I don't have very much knowledge about powder coating."10.06.16More
"Most powder coatings do not run (or sag) easily. This doesn't mean they can't run. If they run the coating thickness is above 25 mils (0.025 inches). That's a pretty thick coating. However, liquid paint can run fairly easily even at a thickness that is under 2 mils (0.002 inches). Therefore, you should check the paint thickness and surface appearance (since most powder coatings applied in thick layers will have more orange peel than liquid coatings). If the coating is relatively smooth and thin, then your paint booth was coated in liquid. If the coating has a lot of orange peel and is thick, then it is probably a poor powder coating.
As for wiping the coating with solvent, this doesn't prove much since some powder coatings can't take that abuse, even if the coating was properly applied. Even the best powder coatings will soften with solvent if they are not fully cured. This is in fact the test used to determine cure (using either MEK or a MEK/Xylene mixture). Bottom line, you need to do more investigation before you accuse your supplier of wrongdoing."
- 124. "I want to powder coat a steel motorcycle frame. However I am hearing conflicting opinions regarding polyester powder. I have been told that it does not penetrate the metal, so when it chips, the frame will sweat and corrode. I have heard there are new techniques that penetrate the metal, and tend to dent rather than chip."10.06.16More
"Most all powder coatings are organic finishes and none "penetrate" the surface of the part being coated. However, they all have great adhesion characteristics if applied to a properly pretreated surface. Contact your material supplier for more information on the recommended pretreatment."
- 125. " I install powder coated hot dip galvanized 100x100x3mm SHS posts to support sails. These are then set in concrete footings. I now have had 2 separate jobs where the powder coating is "bubbling" and lifting away from the steel at the ground level. One job is in a garden bed the other is in a sandstone style poured paving. I would like to know if this problem can be fixed and why it is happening. I would also like to know how to stop it from recurring and how to get the finish back to its original condition."10.06.16More
"You should check the back of the paint chips that have fallen from the posts. I'll bet that the paint chips have zinc galvanizing on the back side, proving that the galvanizing failed and took the powder coating with it. Hot dipped galvanizing is a great corrosion resistant material and hot dipping is the easiest way to apply this material. The only problem is the galvanizing delaminates from the steel surface over time. Often the steel is still covered with some galvanizing that is still intact.
If this is the case, just use a liquid paint to cover the exposed galvanizing. To prevent this from occurring in the future you should use a paintable grade of galvanizing (i.e. electroplating). This way the galvanizing will stay intact on the steel surface. The powder coating will then adhere to a solid surface that will not flake off over time. Remember, powder coating, like all paints, is only as good as the surface it is applied to. If that surface is unstable, the coating will not perform."
- 126. "We are getting all of our products CSA and UL approved. One of the tests that we must meet is a corrosion test for hydrogen sulfide and sulphur dioxide - carbon dioxide. The paint that we use is TGIC polyester powder. Is there a general specification out there that will tell the certification laboratory about the performance of this powder paint with respect to these chemicals?"10.06.16More
"Each powder coating formulation offers a different resistance to corrosion. The coating formulator (manufacturer) may be able to tell you what the corrosion resistance is for your particular powder. However, since you are testing this performance using specific chemical agents, the coating formulator may have to perform the same tests with these agents in order to determine the actual performance. It is not unusual to empirically test powders for determining their performance."
- 127. "Without major modifications, can a paint booth from a body shop be used to apply powder coating?"10.06.16More
"No. A typical automotive body shop booth doesn't have filters that can capture powder particles (overspray). The result will be powder escaping into the surrounding atmosphere and landing on cars in the parking lot. Powder on cars has been known to cure in the hot sun. If this happens, you should expect to be repairing the paint job on all the cars parked in the area around your shop. Pay a few bucks and get an actual powder coating booth. It will be cheaper in the long run when you consider all the car paint jobs you would have to repair."
- 128. "I recently powdercoated some folded 16-gauge sheet metal using RAL colors. The pieces came back from the powder coating shop deformed. They were precisely bent to be used for furniture and had to be "brought back" into shape during assembly. Needless to say they did not return to the required shape. Is this type of deformation common in powder coating steel sheet metal? Is it caused by the heat during the baking process?"10.06.16More
"Normally 16-gauge steel would be unaffected by the powder coating process. Cure temperatures are under 500 degrees F (usually 300 to 450 degrees F).
Steel deformation would not occur until temperatures reach 1000+ degrees F. Most likely your parts were hung improperly or mishandled by your custom coater.�Ask them to be more careful in the future."
- 129. "How well does powder coating protect ferrous metals from corrosion or rust in a marine (salt air) environment?"10.06.16More
"Powder coatings are one of the best performing organic coatings in saltwater environments. Their high dense cross linking provides a coating that is almost impervious to the elements.�This is why powder coatings have been the coatings of choice for use on oil drilling platforms, boating gear, and underwater products.�Of course, to obtain the maximum corrosion performance, you should choose a corrosion resistant substrate, prepare it using a corrosion resistant pretreatment, and apply a powder coating with excellent salt spray resistance."
- 130. "I recently finished a steel exterior deck railing and plan on coating it with a polyester powder.�Will a clear top coat enhance the durability of the finish and protection of the railing?�Is a clear coat standard for this type of application? I like the appearance of the matte look but if a clear coat will better protect and extend the life of the finish I will consider it."10.06.16More
"Don't bother with the clear powder. They are only used to enhance the gloss of the underlying surface and will not improve weatherability. Since gloss is one of the first qualities of finish to degrade as the coating ages, use a good TGIC or acrylic matte black finish."
- 131. "We manufacture infrastructure water valves. Our valves are ductile cast iron and are shot blasted clean after casting. All the carbon scale is removed from the castings. We are currently coating the castings with Epoxy powder, but we run into problems every once in a while with adhesion. The powder coat peels off with little or no adhesion to the castings. Our current powder coat source always blames our cleaning process, but we have inspected our last few shipments and they are blasted very well. The current powder coat source uses a low alkaline wash with a zinc-phosphate pretreatment. There is a silver, almost graphite appearance to the underside of the paint. Any ideas what it may be?"10.06.16More
"We really do not have enough information to make a definitive conclusion. However, if the surface is as clean as you say and has good surface roughness for the coating to bite onto, then the adhesion problem is either caused by too much zinc phosphate or improper powder cure."
- 132. "I am looking for suppliers of powder coating services located near us that have the capability to provide UV cured powder coating to our MDF supplied parts. Are there any suppliers? If so, please supply the contact information."10.06.16More
"The powder coating formulator that makes this powder coating is Rohm & Haas in Reading PA. They call it the Lamineer product. They may know who they sell to that applies this material in your area. Furthermore, you can check the Powder Coating Institute for a list of member companies that apply powder coatings. These custom coaters are listed by capabilities and geographical location.
Product Finishing Magazinehas a shop finder for more information on job shops that apply powder coatings."
- 133. "Is water typically softened in areas where calcium carbonate may be a problem for scale build-up?"10.06.16More
"Water softeners are not the preferred method of improving raw water quality. They use salts that may affect salt spray performance on your parts. The best way for improving raw water is to use either Deionized (DI) water or Reverse Osmosis (RO) filtration. DI is more economical for smaller usage requirements and RO is better for higher usage requirements. Contact us with any other questions."
- 134. "Is a single coat of powder coating over mild steel (14 ga. tube) sufficient for corrosion resistance for an outdoor application? The finished product is a fence."10.06.16More
"You better have a detailed specification written for the person coating this fence product otherwise it may not perform as well as you would like. This specification would detail pretreatment, primers, topcoats, etc. to ensure a 20 year life on steel. A single coat of powder over mild steel without proper pretreatment, primers, etc. may only last one to 5 years.
However, an outdoor durable powder topcoat over the right primer and pretreatment can give you 10 to 20 years, or more life, depending upon the part of the country it is installed. A good pretreatment and a single coat of powder over aluminum can provide 20 years life, easily. I hope that this helps. Oh, by the way, we write these types of specs all the time for our clients."
- 135. "Aerospace manufacturers are being faced with increasingly tougher environmental regulations. We are using more and more High VOC and water based coatings but that is still not enough to meet the environmental regulations. Can you indicate if any powder coatings meet the aerospace industry standards such as Boeing's BMS 10-11, BMS 10-79, BMS 10-72, BMS 10-60, Canada/Bombardier's CMS 565-01, CMS 565-02, CMS 565-08, CMS 565-09, CMS 565-10 ? Thank You for your time and consideration."10.06.16More
"I suggest that you contact the Powder Coating Institute in Alexandria, VA. Telephone number is (703) 684-1770. They may have an answer for you on mil-spec and aerospace-spec type powders. Ask them for their membership information brochure, which includes the names of powder coating formulators, each of whom may have approved materials for your use."
- 136. "Part of our recovery from Katrina is replacement of a U-shaped reception station which has front and side panels that approximately 40" high. We have located a company which manufactures an extremely attractive unit which is available with either power coated steel or laminated wooden panels. Dogs of various sizes frequently "climb" the front panel of the desk presumably to assist their people in writing checks or to help themselves to the candy bowl, or us in answering the phone or handling various tasks. I'd appreciate your thoughts on the relative durability and dog-claw scratch resistance of powder coatings compared to quality laminates, some of which are described as "fused" laminates. "10.06.16More
"You should expect the powder coating finish to perform much like the coating on your refrigerator, kitchen range, washer & dryer, lawnmower, lawn furniture, etc. All these products are powder coated. Powder coating is a very durable organic (paint) finish. It is not impervious to scratches and nicks, but is damn close. A laminate will wear like your kitchen countertops (as long as you don't have granite countertops). They can be cut and chipped under very arduous conditions, but for all practical purposes are bullet proof."
- 137. "We are interested in reusing the over-spray from our powder line. We change colors often so the collected powder is quite a mix of colors and chemistries. What we would like to do is reuse this powder on elements of our products that are not visible. We are painting steel office furniture components. Our tests so far show that the paint adheres just fine to the metal and has good durability. There are a few contaminants that get into the powder during the collection of the overspray, mainly shop dust. Any way to re-filter the powder or prevent dust from getting in the overspray during collection? Are there any other unforeseen problems using recycled powder? "10.06.16More
"If you are comfortable with the look and function of this mixed reclaim powder coating material, then by all means use it. Mixing different powder coating chemistries can have disastrous effects. Often the coating will have "fish eyes", voids, speckled colors, cracks, wrinkles, etc. It will be particularly hard to determine the physical properties of such a mixed coating, especially if the powder chemistries are very different and incompatible. But if it works for you, go for it. As far as cleaning up the reclaim, removing oversized particles, etc., you need to use a sieve. If you are processing this reclaim in batches a batch vibratory sieve from Vorti-Sieve should work fine. If you want to process this reclaim "on the fly" and continuously, then a rotary sieve from Azo or Prater will do the trick. "
- 138. "What are the heat dissipation properties of powder coating? In outdoor use, specifically with stadium seating, will a dark color conduct more heat than an anodized finish? "10.06.16More
"The answer to your question is not related to powder coating. Dark opaque colors absorb heat and light where transparent colors reflect heat. Anodizing will reflect heat energy while a black powder coating will absorb heat. The heat that is absorbed by the coating will be conducted to the base metal, called heat transfer."
- 139. "Please explain the process in powder coating a 24 ga. rolling steel door at the factory vs elecrostatic field application paint. Which is better, why, and the exact process they would go through. I am needing this for an architect. Thanks for your help!! "10.06.16More
"Powder coating is a factory applied finish that employs several steps (wash & pretreat, dry, spray, and bake cure). Electrostatic-field applied finishes use liquid coatings that are either air-dried or two component cured. Functionally, factory-applied powder coatings will outperform most field applied liquid finishes because of the excellent surface preparations and better properties of powder coatings. Powder coatings cannot be applied reliably in the field, especially to a rolling steel door. "
- 140. "My application is spraying clear powder on to a plated surface. There is less than 1 mil of plating thickness. Will the nominal cure temp (350 - 400 DEG F) induce discoloration of the substrate for "Unstable Finishes" such as brass and bronze? "10.06.16More
"Depending upon what salts and soils are left on the surface and the rate of temperature rise on the part during curing, the simple answer is yes. Polished brass surfaces have successfully been powder coated after great care has been taken to ensure that the surface is completely clean and neutralized and the curing temperature is gradually induced into the part using convection heating techniques."
- 141. "I am planning on powder coating an electric motor. The motor has an aluminum case, steel covers with a conversion coating on them, and a steel armature shell that is pre-painted. The motor is not sealed and therefore cannot be washed. What would be my pretreatment options? The motors come clean from the supplier, but is that clean enough for a powder finish? "10.06.16More
"You raise an interesting question, How clean is clean enough for powder coating? Liquid coatings that contain petrochemical solvents can "bite through" light oils left on the part`s surface to provide adequate adhesion. Since powder coatings do not contain any solvent, residual oils left on the part surface can be an impediment to proper adhesion. Furthermore, organic soils (such as oil) can bleed through light colored powder coatings under the high heat conditions experienced during the cure cycle. For these reasons it has always been good practice to scrupulously clean the surface prior to applying any powder coating."
"However, cleaning requirements can be less critical if the powder coated product does not have high quality appearance and adhesion standards. The coating performance depends upon perceived quality requirements and will dictate the appropriate process requirements. This fact is proved in the automotive industry where under carriage parts have a 336 hour salt spray corrosion requirement and the body parts have a 1,000+ hour salt spray requirement. In this case, the automotive companies sense that their customers will accept rust in short order on the car`s suspension springs but not on the car`s fenders. Therefore under carriage parts are pretreated much differently than body parts. Using the same pretreatment for all parts will ensure that either the body parts will not perform up to expectations or the under carriage parts will be too costly to manufacture."
"How clean your motor housings need to be is dependent upon what your customer expects from the powder coated finish. Understanding this requirement is paramount for determining the appropriate finishing process. You have several options to clean your motor parts prior to applying the powder coating:
- Do not clean the motors at all. This may provide an adequate solution since the parts are cleaned and pretreated prior to arriving at your facility. Use clean lint-free gloves to handle the parts prior to powder coating. Remove any loose contaminants such as dust and dirt before coating.
- Use a vapor degreaser to remove any residual soils on the parts prior to powder coating. This method of cleaning has been under scrutiny by the EPA, so be sure you are in compliance with all federal, state, and local statutes.
- You can solvent wipe these parts prior to coating. Be aware that this method is suitable for lightly soiled substrates. Change your wiping rag often to prevent reapplying the oils. OSHA, EPA, and the local Fire Marshall closely watch this method of cleaning, so be sure that you have plenty of ventilation and are in compliance with all other safety and disposal requirements."
"Try a test batch of products to ensure that the chosen method will work consistently in your facility. Check the parts for proper adhesion after they are fully cured. Also, be sure to run any performance tests your customer may require on these motor housings. If the test results are acceptable, then you have a successful powder coating process."
- 142. "I work for a leading manufacturer of recirculating baths and chillers. We are currently bringing a white powder coating operation in-house. Case assemblies with this white polyester powder coat receive a teal band with the company logo and model, which is screen printed onto the case. My question is: what types of ink will exhibit strong adhesion and scratch resistance to a polyester powder? Our current air dry ink is fine for text and symbols but is not durable enough for a 2" x 6" band."10.06.16More
"Your powder coating supplier will have the answer for you. It is important that you tell him/her that you intend to silk screen over the powder, since they must modify the formulation to accommodate this. They may tell you that the powder material that you have selected will not accept a silk screen ink. If it does, then they can tell you which inks are the most appropriate."
- 143. "I currently build weight lifting equipment that is designed for people who are confined to a wheelchair, but it is also designed for the able bodied as well. I am subcontracting my Powder Coating operations, and have had problems with my supplier. The next closest supplier is about 200 miles away. We are planning to move our shop and are considering bringing this operation in-house.
So the main question is how hard would it be to get involved in purchasing our own powder coating setup to do our work as well as do work for other locals. Currently our largest solid piece that we powder coat is approximately four feet by eight feet. What kind of cost would we be looking at for a setup that would meet our needs.
Thank you for this opportunity to ask some questions and thank you for your time and effort."10.06.16More
"Call the Powder Coating Institute and ask them for their "Custom Coaters Directory" which lists many powder coaters around the country. There is probably a reason there are a limited number of people who provide this service in your area; not enough business to support more custom coating companies. This may influence your decision to open a competing shop.
The cost of starting a powder coating operation, with new equipment, starts at $50,000.00+ for a batch system and can approach $1,000,000.00 for a conveyorized system without much effort. The only difference between these two systems is the amount and size of product it can process in a given period of time. For your reference, a powder coating gun costs approximately $4,500.00 each, spray booths start at $10,000.00 each, and that doesn't include the cure ovens and pretreatment systems that are necessary for this process."
- 144. "I have been experiencing what I call a surface tension pull problem with epoxies, hybrids and TGIC's in a 90 degree bend area. I know that it is not a Faraday Cage effect, because the parts are inspected before they go into the oven, and all areas are covered with powder. After the parts come out of the oven, the powder has pulled away from the corner during the cure cycle after the powder has "flowed". This is evident by the random pattern of separation.
To add to the mystery, this only happens with non-textured powder. My requirements are to have both a textured powder and a non-textured. I need some chemical resistance to the finished product. I have been focusing my energies on trying to identify a hybrid powder. The customer has turned down urethane as an option.
What do you suggest? Thanks in advance."10.06.16More
"The problem you are experiencing is the result of poorly charged powder due to a Faraday Cage. The powder that you see in the corner before cure is not fully charged and falls from this surface when subjected to heat. This situation has happened before. This is a difficult problem to solve, since you need lower charge on the powder particles to get it to go into the Faraday Cage and then when these lower charged powder particles are put into the oven they fall from the surface.
Here are three solutions:
1.Use a tribo charging gun to coat this area.
2.Orientate the part so that the Faraday Cage is at the bottom and hope the powder flows into the corner.
3.Contact your powder supplier to obtain a powder coating formula with lower flow characteristics. (less flow) "
- 145. "We are a manufacturer of carnival games and one of our products is exposed to the elements (i.e., sun, rain and salt air). We have been using a metallic silver that became a problem for us. The customers had complaints that it was rusting prematurely. We found out that our supplier was not using a clear coat and that was the cause for the rusting. Now our problem seems to be that the clear coat is yellowing within a 6 month period. I have been told that this is caused by leaving the material in the oven too long. Could you please confirm this or advise me on the proper procedure?"10.06.16More
"You should review this situation with your powder coating material supplier. They understand the formulation intimately and can recommend the most appropriate action. Having said that, below is some general information:
Clouding in clear powder coatings can be caused by under cure, over cure, contamination in the coating, UV instability of the formulation, improper oven exhaust rates, and improper formulation. The powder supplier can help you determine which problem is causing your clarity problem."
- 146. "Is there a way to correct oil or grease stains without reworking the product. We presently attempt to use matched paint or resort to sanding and recoating finished product. Recoating tends to leave an orange peel effect."10.06.16More
"These stains are indicative of residual oils left on the part prior to powder coating. Posssibly they are bleeding from hidden area, such as at spot-welded joints. In either case, the stained area will probably fail before the other areas of the part. Therefore, if you are looking for consistent quality from part-to-part and within the same part, then you must sand the area and recoat. However, if potential failure of the coating in this area isn't a concern, then try cleaning it with a strong solvent and touch-up with liquid paint. Be aware that these areas will not be as good as the original powder coated surface."
- 147. "We are a Biomedical Engineering Government department servicing the northern Sydney region. We would like to find a supplier of the raw material/s used in the coating of electrosurgical instruments. We would also find useful any information on equipment and techniques used in this process."10.06.16More
"There are many companies that use powder coating for surgical instruments. They purchase powder and pretreatment chemicals (raw materials) from many companies (68 powder companies in North America alone). Similarly, there are several equipment companies that sell the application equipment employed in this process. To obtain the names of these companies you should contact The Powder Coating Institute in Alexandria, VA (703) 684-1770 and ask for their informational brochure and list of member companies. Unfortunately, it is difficult to determine which of these companies support the medical instrument industry. However, it wouldn't be to difficult for you to determine your unique process requirements and finish performance requirements so that these vendors can sell you an appropriate solution. Contact us if you need help to determine your requirements."
- 148. "I am assisting a customer to decide if powder coating is the change to make. Currently uses a five stage pretreatment to the aluminum. How much less pretreatment of aluminum is needed? I know the answer depends on the exact metal to be coated but do you have a ballpark answer?
Secondly, I hear rumors of UV fading. Any information available on this issue?"10.06.16More
"The five-stage pretreatment sounds ok, depending upon what each stage is doing. Powder is used in all sorts of outdoor applications without UV problems. The only thing that needs to be considered is which powder to use (based upon your customer's performance requirements). Powder coating over chromate conversion coatings on aluminum can provide 5000 hours salt spray resistance and can translate to over 20-year life (in outdoor environments). We can be contacted through this web site or by telephone (800) 97-POWDER."
- 149. "I have a customer who wants to use electrocoat on an aluminum casting as a primer for powder coating. Can e-coat provide a good base in this application, and if so, what coating material and method would be most suitable. The product would be in a marine environment."10.06.16More
"E-coat is an appropriate primer for powder top coats. In fact, this is the method preferred by customers looking for the best corrosion protection available with organic coatings. There is only one way to apply an e-coat primer; with an e-coat system. There are a couple of ways to employ the e-coat process (autophoretic, etc.). Check with an e-coat material supplier for the best material and methods for your specific product. PPG is a premier supplier of e-coat materials. Be advised that if you do not have a source for getting this coating applied by an outside contractor, you will be looking at a substantial capital investment (can be $1.0 million). Good luck."
- 150. "We are looking for a supplier of powder coating that will be used as a mold release agent for the bakery industry. Also, we would like information on the company that would help us on the cleaning of these bakery molds."10.06.16More
"There are several powder companies that make mold release for the fiberglass industry (referred to as "in-mold coating"). Also, there are many powder companies that make FDA approved powder materials. However, I do not know of any company that makes mold release compounds for the bakery industry.
I am not entirely sure what you are looking for in this application. For instance, if you need a slippery compound to be permanently bonded to these molds(like Teflon), or if you want an edible material to be sprayed onto the mold.
Please feel free to re-ask your question with this additional information."
- 151. "Powder Coating Using IR Furnace for the Coating of Sheet Steel: Hi, I am a student at the University of Wollongong NSW (New South Wales) Australia and am working on heat distribution and modeling as shown above. I would appreciate any contacts you may be able to suggest. Looking forward to your reply..."10.06.16More
"BGK is a premier manufacturer of such IR ovens. Their address is:
BGK Finishing Systems, Inc.
4131 Pheasant Ridge Drive NE
Minneapolis, MN 55449
Telephone: (612) 784-0466 "
- 152. "How do you improve salt spray on TGIC powders? Are TGIC powders poor choices for good salt spray resistance?"10.06.16More
"TGIC polyester powder coatings are formulated for superior outdoor weatherability and corrosion resistance. To improve salt spray, look to your pretreatment chemistry and/or your substrate materials for alternatives that will provide better salt spray characteristics. Also, look to your process control for improvements on the current materials that you are using."
- 153. "What are the main functional differences between epoxies, urethanes, TGIC's and hybrids?"10.06.16More
"There can be many subtle differences between all these coatings, and many features can be formulated into each coating. However, the general functional differences are as follows:
Epoxies are very chemical resistant but have no UV resistance (weathering).
Urethanes have great weathering characteristics but do not have good flexibility in impact resistance.
TGIC Polyesters have good weathering but reduced chemical resistance.
Hybrids is a term that describes a mixture of resin technologies. Depending upon which resins are used, they can have all sorts of properties. One of the most common hybrids is an epoxy-polyester hybrid which has most of the properties of pure epoxy coatings with some added UV resistance (weathering) of polyester coatings.
There are many more features and properties in each of these coatings that you should discuss with the material suppliers."
- 154. "We are preparing to coat 2B stainless steel with a polyester powder. The final product will be an outdoor constant temperature device. Our pretreatment is one stage wash/phosphate and two rinse stages. The parts are then run through a dry off oven before coating. Should we expect any adhesion problems? Will this finish stand up to various weather conditions? Is there an alternative to stainless?"10.06.16More
"Stainless steel is very difficult to coat without adhesion problems. The iron phosphate will do little to prepare this surface for adhesion.
Pretreatment for stainless steel is focused towards adhesion, since corrosion resistance is not a problem with this substrate. You should review your requirements with your chemical supplier and ask for his recommendations.
Changing the substrate to galvannealed steel can provide for better adhesion; however, it will not perform as well with corrosion. Review your performance requirements carefully before you select a substrate material."
- 155. "I am looking to purchase a powder coating company. Any general suggestions on what to look for? They are doing about $16,000 per month in gross revenues."10.06.16More
"Find out how profitable they are! That is the only question you should ask when purchasing a company."
- 156. "I would like more information to answer why after application of powder coat on architectural aluminum extrusions the coat chips or peels off, even after we had applied chemical treatment. Please advise us on how to make better process. Hope to get your prompt reply. Thank you."10.06.16More
"Loss of adhesion with powder coating can be caused by any of the following:
1. Poor surface cleaning.
2. Poor surface pretreatment.
3. Under cured coating.
4. Over cured coating.
To know what is causing your particular problem requires some detective work. If there is foreign matter on the under side of the chip, then your problem is in the pretreatment of the product. If the chip is clean, then check your cure. Good luck."
- 157. "I need used powder coating equipment such as: ovens, pretreatment equipment, and suppliers of new and used equipment.
Also, I need some info on demographics of the powder coating industry in the southeastern region. Any information that might help in doing a business plan for starting a powder coating business."10.06.16More
"Used equipment can be found from many sources. There are used equipment dealers that advertise in the trade journals. Also, there are private parties that are selling their old system as used equipment. Look for these in the classified section of the trade journals.
There are no marketing studies for the end user in the powder coating industry for under $2,000.00. The studies that are available are mostly for equipment and powder suppliers and not end users. You will have to do your own market survey for the area that you want to service with your new business."
- 158. "I am planning on setting up a powder coating plant in Vietnam (Southeast Asia). Would you recommend a reputable equipment supplier who can give me a quotation. Thanks."10.06.16More
"Contact the Powder Coating Institute in Alexandria, Virginia, (703) 684-1770. Ask them for their "Information Brochure" which will provide you the names of their member companies that sell powder coating equipment."
- 159. "I have a customer that requires a transparent blue (candy) polyester over a white base. This is on a Go-Cart frame. We are having trouble getting even coverage on all parts of the frame, mostly on the ends of the tubes. No matter how much powder we put on, the ends come out light. Any suggestions would be greatly appreciated."10.06.16More
"Evidently the powder formulation that you are using does not have good "edge build" characteristics formulated into the coating. You should contact your powder supplier for further explanation."
- 160. "Do you, or any of your "readers", have experience of using ionized air knives to remove debris from work immediately before coating? I am being introduced to this by several keen salesmen who make great claims, but cannot yet supply a "satisfied user" list as, they claim, the technology is too new."11.06.16More
"Ionized air knifes have been used in many applications where the product being coated has charged contamination adhered to the surface. If this isn't your problem, then you don't need the system. The problem with air knives is they use compressed air, which depending upon the volume, can be very expensive to make, dry, and filter. A system that has gained acceptance in our industry, when compressed air costs are too high, is an ionized blower system. This design uses the same ionized generator, but uses an electric blower to supply the air instead of compressed air. I hope this answers your question."
- 161. "Need info on powder coating exhaust pipes for vintage Harley Davidson in a white gloss finish that will withstand heat of exhaust. Thanks."11.06.16More
"You are looking for a high temperature powder coating, of which there are a few on the current market. However, I do not know of any high temperature powder coatings that come in white. You should contact H.B. Fuller, who has the most products in high temperature formulations, to ask them. Good luck."
- 162. "I want to create a storage room for powder paint. Can you recommend the appropriate Storage temperature, humidity and air velocity needed. Also are there any regulations as to the design or safety aspects of this storage area."11.06.16More
"The temperature for a powder storage area should be held between 60-80 degrees F. The relative humidity should be less than 60%. As far as codes, you should check with your local fire marshal and building department for the fire rating of the structure and what fire protection/suppression systems are required. Your insurance company should also be asked if they have any special requirements."
- 163. "We have some steel panels, approx. 4' x 4' in size. Several were blemished when we powder coated them. Coating was about 2 mils. We have found that we can remove the blemishes by sanding them with an orbital sander, removing about 0.5 mils of coating. But this has created another problem -- the panels become so "charged" by the sanding that they attract dust and dirt particles which contaminate the surface so that when new powder is applied the finish is "gritty", not smooth. Can you tell us some simple way to "discharge" these panels? Thank for you help."11.06.16More
"Usually rinsing the substrate can neutralize the surface, if it is grounded during this procedure. There are ionized air blowers and compressed air units that can neutralize the part's surface. Check the Thomas Register under Ionized air systems for manufacturers names."
- 164. "It has been brought to my attention that there is a process that uses epoxy powder coating waste as an extender in other resins. I am aware of some "overspray" that is collected and used for a clean down process, but I have not heard of using this material as an extender. Can you shed some light on this subject?"11.06.16More
"This would involve the details of powder coating formulations, which are often carefully guarded by the powder manufacturers. It is not generally a good idea to just mix powders on the fly. You might try contacting the Powder Coating Institute for more information."
- 165. "We are looking for a low temp cure (less than 300F) flat grey epoxy, powder or other material capable of withstanding a 300 hour salt spray test. A 4H hardness is a plus. Developed for IR cure would also be a plus. Thanks for any help."11.06.16More
"There are several powders that are formulated to cure in under 300 degrees F. Contact the Powder Coating Institute for their membership directory which lists some suppliers."
- 166. "I have encountered a problem with a certain Company's polyurethane. When used on extruded Aluminum and some cold rolled steel applications it gives an outgassing effect. Is this a normal reaction or could it be a pretreatment problem, or should I look to the distributor of the product for my answer? The Company's Rep that looked at the problem when it was first encountered did not have an acceptable answer for me."11.06.16More
"Outgassing can be caused by contaminants on the substrate or from the powder itself, if it is applied too thickly. You should definitely contact the manufacturer of the material for some guidance."
- 167. "Our rinse water has a dissolved solids content in excess of 1300 right out of the tap. Can you tell me exactly what the maximum dissolved solids content should be? Can you also tell me what exactly should the water make up be?"11.06.16More
"The water quality should be less than 250 ppm of CaCO3 and less than 100 ppm of combined chlorides and sulfates. If your water cannot meet this criteria, you should use demineralized water (either ion exchange or reverse osmosis)."
- 168. "I had a front wheel for my Harley powder coated and the chrome around the rim bubbled. Harley does not want to touch it nor does the powder coater. Any advice? The wheel was chrome around the edge and unpolished in the center where the coating was done."11.06.16More
"Get your money back. There is nothing that I can tell you to fix your problem, since you don't have the process equipment. Bubbles can be caused by contamination on the substrate and/or corrosion after the part has been used for a while. Good luck."
- 169. "My employer is putting in a new powder line. We spray high solids. Currently it is suggested that we use a high velocity cure oven with a 1 minute gel zone. This is new technology for our company and I can't afford to be a guinea pig. Does it work ? We use 10 to 20 gauge metal and will be spraying white powder. I am concerned about scorching the parts. What advice would you have?"11.06.16More
"There are many issues that need to be discussed as part of your conversion to powder. We cannot possibly address them all in this forum. Please contact us at (800) 97-POWDER and we will be very interested in discussing our services with you."
- 170. "I need a material that is recommended for engine blocks as well as a coating that is extremely chip/mar resistant. Any suggestions?"11.06.16More
"Since engine blocks are not exposed to sunlight, then UV resistance shouldn’t be a coating requirement. If you agree with this, then I suggest that you investigate using an epoxy powder coating. This material has excellent chemical resistance (oil, gasoline, etc.) and is very durable (chip & mar resistant). Furthermore, epoxies are very inexpensive and can provide an excellent coating in non-sunlight exposed products. If exposed to sunlight (UV light) epoxies will tend to chalk. Chalking will not adversely affect any of the previously mentioned coating properties of this material."
- 171. "I need some help in determining the applicability of post forming powder coated aluminum products. Briefly, what is the current "State of the Art" technology, and what are the restrictions?"11.06.16More
"Many powder formulations have post-forming capabilities. The typical resins used are epoxy and polyester. Although both of these can be formulated for post forming, they have different UV resistance characteristics. This highlights the need for a well defined powder coating material specification that lists ALL your requirements so that your coating selection can achieve these requirements. This will insure that you purchase the powder coating that fits your requirements and not a coating that a salesman wants to sell you.
There aren't any "State of the Art" coatings for a post-forming environment. Powder coatings have been used for years in applications where a zero "T bend" is a requirement."
- 172. "I'm customizing my Harley and would like to know what effect powder coating would have on the engine. It's a daily rider, not a show bike. Will the powder coat have a positive or negative effect on the air cooled motor? Any help would be appreciated."11.06.16More
"There should be no adverse effect if the coating is applied properly at the recommended film thickness. Many people have already gone this way with no problems."
- 173. "Does anyone commercially produce rigid or flexible PVC spray coating? Do you know of any additives that will enhance adhesion to metal using PVC? We are working to develop such a product. We have had some promising success and the answers to the above would be most helpful."11.06.16More
"PVC coatings are thermoplastic resin systems that are almost always "flexible". The powder formulators that manufacture these coatings also have liquid primers that greatly improve adhesion on most substrates (including metal). I hope this helps you in your project. You can call us at (800) 97-POWDER for more information."
- 174. "Are there any adverse adhesion problems with TGIC Powder over anodized aluminum, and what kind of longevity can be expected in an oceanfront application? "11.06.16More
"There should be no adhesion problems if the substrate is properly cleaned prior to applying the powder coating. Check with the powder supplier and pretreatment supplier before proceeding.
Life cycle of TGIC polyester over an alodine (chromate conversion coating) is 5000 hours of salt spray. An outdoor furniture supplier, who sells to beachfront resorts guarantees this finish for 20 years. You will have to determine what this means to you with TGIC over anodized aluminum."
- 175. "Are there any publications especially concerned with the particle sizes of the powders used in powder coating? I'm interested in preferred particle size distributions. Are the particle size distributions preferrably broad or narrow? It would be very helpful to get some general information about that or to know how I can get some in the scientific literature or maybe in patents. Is there any sort of book that might be called 'The bible of powder coating' where I can find something about that problem, or which gives a deep insight in the basics of powder coating? Is there any database on the WWW where I can obtain any kind of information on powder coating? Thank you very much for your help."11.06.16More
"The book that you want is available from the Powder Coating Institute in Alexandria VA. Call them at (703) 684-1770. Ask for the "Powder Coating Handbook" ($75.00 US plus shipping and handling). It's a good book and recommend it to anyone interested in getting more information on powder coating. Nick Liberto of Powder Coating Consultants was the Editor and a contributing author."
- 176. "I have a relatively simple question. I am an ornamental metal fabricator, and have had a few things coated. I see a great potential in the process for my work, but the coater in my area had very little information to offer on what is possible. Is there an information clearinghouse where I could learn the available pigments, textures, etc.? This information would enable me to fully utilize the services offered by the local coaters."11.06.16More
"You can call the Powder Coating Institute (703) 684-1770 and ask them to send you their membership directory which lists all the member companies who formulate powder coatings. Contacting these vendors directly will allow you to obtain their color charts and product descriptions for their "stock" materials. You will see that there are a wide selection of colors, textures, wrinkles, gloss values, clears, tints, flamboyants, etc. I'm sure that if you have seen a specific look in paint you can get the same look in powder coating."
- 177. "I have a question about an electrostatic gun's behavior in a coating booth. We have a powder coil coating line for precoating galvanized & aluminium coils up to 48" wide. It is observed that the kV at guns tip drops to 50-60 level when guns are in installed conditions inside the coating booth made of 304 grade S.S. - compared to readings of 80-90KV when tested outside the booth. 6 nos corona type guns are normally used at a time in this booth.
To our mind this is one of the reasons for low transfer efficiency of around 60% as against expectation of 85-90% since object is flat strip. What steps could be taken to avoid / minimize kV drop?"11.06.16More
"KV's (voltage) will drop as microamps (current) goes up. This is determined by the laws of physics. You are probably bleeding your corona field towards the booth, and definitely to the metal strip you are coating. Therefore, a drop in KV is very likely.
The important thing is to ensure that the KV's are being directed toward the strip and not the booth. Check and adjust the position of the guns to be sure that the primary target is the strip and not the booth. Monitor the current (microamps) during spray and compare them to readings taken without powder spray. They should be higher when spraying. If all else fails, call your equipment supplier."
- 178. "I am very interested in starting my own powder coating business. Any information you may have on start up cost of a batch system, I want to use a 10x10x20 oven; if available. I want to start off with only the equipment I absolutely need. Any help you could send my way would be greatly appreciated."11.06.16More
"The cost for a batch powder coating system of the size that you are considering is as follows:
Gun & Feed system = $5,000.00
Spray booth = $10,000.00
Cure oven = $30,000.00
Pretreatment & Cleaning system = $10,000.00
Total investment = $55,000.00, you could save some money if you can locate some used equipment."
- 179. "I need to "paint" some electronic housings that are supposed to also function as heat sinks. What would be the best powder type to use for such an application? The best thermal conduction and heat emissivity properties are what I am looking for. Can you please help?"11.06.16More
"Most thermoset organic powder coatings will not conduct heat as well as an uncoated part. Therefore, you can assume that all these coatings can be considered thermal barriers to some extent. The most important issue is not which coatings are best for this application, but rather which color and what thickness the coating should be. For instance, black is the most appropriate color for thermal transmission. It shouldn't be applied more than 2.0 mils thick."
- 180. "I am doing research into powder coating and its usage in the automobile industry. Are there special requirements for powder coating cars? Is it already being used by automobile manufacturers? What are the advantages or disadvantages of powder coating ?"11.06.16More
"It has been well documented that powder coating has been used in several key areas in the manufacturing of automobiles. For instance, under-hood (oil filters, etc.) and under-carriage (coil springs, etc.) parts have been powder coated for years. Some exterior trim components have also been powder coated. Selected areas of some vehicles have been powder coated for anti-chip protection (rocker panels, etc.). Entire vehicle bodies have been fully primed with powder coating. In the USA market the next growth area for powder coatings in the automotive industry is clear-coating the entire vehicle body. Don't expect to see the color coat of the vehicles to be powder coated in the near future, since the 8 second color change requirement has been difficult to overcome with current technology (we just can't seem to get the previous color out of the booth air stream in that 8 second time frame)."
- 181. "I am interested in using powder in place of our existing paint finish. Is there some data published displaying a quantitative comparison of powder to liquid paint? My experience with local vendors is that they quote qualitative comparisons, i.e., "Powder coating is 2-4 times harder and more durable than [liquid] paint". It is very difficult to convince management to authorize a change based on this type of reply. I need economics. Any help would be greatly appreciated."11.06.16More
"There is a software program we developed for the Powder Coating Institute that uses a spreadsheet to compare typical powder coating operational costs to liquid coating costs. This spreadsheet is modeled after the PCI Technical Brief #21 that has been used for years to compare the most obvious operational cost differences. The diskette is free for the asking . This will provide the data that you are asking for in a clear and concise manner."
- 182. "Where can I get information regarding military standards sampling procedures of powder paint (specifically MIL-STD 105d)?"11.06.16More
"The Powder Coating Institute in Alexandria, VA has a government relations committee that deals with military standards and specifications. They can be reached by telephone at (703)684-1770. Good luck!"
- 183. "I'm in urgent need of a source for raw material, equipment, and technical instruction for applying coatings on ceramic craft. We will be transferring images onto the surface via the sublimation printing method. Thanks.11.06.16More
"Contact us for information about our rates. We have the expertise you require."
- 184. "I'm in the process of restoring an Austin Mini Cooper. The car has front and rear subframes which hold the drivetrain and suspension pieces. I'd like to powder coat the subframes primarily to protect them from rust, as they have areas that tend to trap water and mud, as well as to ward of chips from road debris or damage to the finish from oil or gas.
I would like the finish to be a semigloss black. What material and/or process would you recommend?
Would it be necessary to mask off threaded holes, or can one just run a tap into it to clean out excess material?
If masking is necessary, what's the recommended procedure to best withstand the heat?
Also, could you explain the Faraday Cage Effect and how to avoid it, as the subframes have numerous corners inside!"11.06.16More
"The best powder coating material to use is epoxy, for its chemical and chip resistance. Be aware that this material is not UV stabilized and will chalk over time if exposed to UV light. If UV stability is required, then I suggest that you use a polyester material, which is stable under UV light conditions and will not chalk, but has some reduced chemical resistance when compared to epoxies.
The procedure that I would use is to sandblast the entire frame and pretreat it with an iron phosphate chemical using a spray wand system. After the frame is completely dry, powder coat it completely with about 2 to 3 mils thickness. The frame must be put into an oven to cure the powder coating for 20 minutes at 375+ degrees F.
Operator techniques are the best way to overcome Faraday areas. I wouldn't worry much about them, since you can always touch-up those areas with liquid paint after the powder has been cured."
- 185. "We're looking for comparative analysis for powder, spray, and e-coat technologies if any exists. Do you know of a source for this type of information? My primary interest is in making sound economic and environmental choices in selecting a proper surface coating technology."11.06.16More
"There is no direct analysis between e-coat and powder coating that we're aware of. However, there is a comparison between liquid spray and powder coating implemented as a computerized spreadsheet. This spreadsheet software is available from the Powder Coating Institute (PCI)/ 703-684-1770.
If you use this spreadsheet for e-coat, remember to adjust the coating thickness and the efficiency rating for that technology. We developed this spreadsheet application for PCI and can assist you in your comparison for a fee. If you are interested call us at (800) 97-POWDER."
- 186. "We use a lot of galvanized steel. Not always but quite often we have gassing problems with powder coating on galvanized steel. What are the reasons and how could we solve this problem of bubbling. Kind regards."11.06.16More
"Galvanizing can be accomplished in several ways. Depending upon which method is used will effect your outgassing problem. For instance, if the part has been hot or cold dipped galvanized, then trapped gasses are likely. When the product is heated these gases are released and cause holes in the coating. Other methods of galvanizing, such as electroplating or galvanneal products will not outgas at all. To eliminate the outgassing either change to a galvanizing process that will not entrap gasses (i.e. electroplating or galvanneal), or preheat your product to the cure temperature to release the entrapped gases prior to powder coating."
- 187. "Please advise on recommendations for pre-treatment through to powder coating of material supplied as galvanized. The intention would be to hand supplied material from supplier with the process performing all functions such that finished powder coated material would be removed from the line, packed and shipped. Thanks."11.06.16More
"The first step is to use a paintable grade of galvanized steel (i.e. galvanneal, paintgrip, or electroplated galvanized). Hot or cold dipped galvanized steel will cause problems with out gassing and powder adhesion.
The preferred pretreatment for galvanized steel is zinc phosphate. This will provide prolonged salt spray resistance and excellent adhesion. A chrome sealer rinse would also be nice, if you can use that material in your country. The pretreatment system typically has seven or more stages to apply these chemicals, depending upon the soil load on the raw product. You should contact a competent pretreatment chemical supplier for help in selecting the right chemistries.
The product should be perfectly dry before powder coating. A dry-off oven suits this task well. The part should be cool to touch at time of powder coating. Coat and cure the product as normal with your equipment."
- 188. "I am using brushed aluminum in an outdoor environment. Can bare aluminum be powder coated clear, and if so, how long can I expect such a coating to endure outdoors? Is there a powder formula that you would recommend for such an application?"11.06.16More
"To powder coat aluminum, you must have a completely clean surface. Normally aluminum has some oxides on the surface that can cause problems with adhesion and corrosion protection after coating the substrate with powder. These soils must be removed for the powder coating to provide maximum protection and excellent clarity through the coating. Fluoride in solution is normally used for this purpose. Review your specific requirements with a knowledgeable pretreatment chemical supplier for further information."
- 189. "Has anyone come up with a device to measure uncured powder on parts that are moving? I heard a while ago that something was under way but didn't know what it was. I would think a laser would do the trick. Then, that could be related to what the dry film millage would be."11.06.16More
"There is one equipment supplier that sells a laser device to measure uncured powder coating thickness. The device is quite costly, approx. $60,000 +, and can tell you the coating thickness in the exact location where the laser hits the target. No information is provided form any other locations on the coated surface. You would have to have one heck of a gun set-up to ensure that the entire surface is coated with the same thickness as the area measured by the laser. The equipment supplier is Wagner-Reclaim, and they are located in the Chicago area.
One point to remember, is that powder coating thickness shrinks as the coating melts and cures. So the reading may be on the high side when compared with the after cured thickness measurements. This situation may be corrected with the laser equipment through calibration. Check with the supplier for more details."
- 190. "At work, we are experiencing many cosmetic issues on our black powder coated aluminum parts. We are seeing variations on heavy coverage and light coverage within a shipment and sometimes within each part. The dimension of this part is 1" X 3" X 0.030" thick. In addition, this part must have a matte finish(rough finish) and our powder coating vendor is having a processing difficulty due to the texture requirement. I not sure the matte finish is very hard to obtain regardless of the powder suppliers or there are other processing issues which my vendor should pay more attention to. I am looking forward to hearing from you."11.06.16More
"Matte or textured finishes are more difficult to formulate and apply than high gloss powder coatings. However, there are over 75 powder formulators that have provided such materials on a consistent basis to many end users. If you are having trouble with your current supplier, then I suggest that you look elsewhere.
Most powder coating formulators are listed with the Powder Coating Institute. Call them at (703) 684-1770 and ask for a membership directory. As in any industry, there are different levels of expertise with the different suppliers. As late, many regional liquid formulators have entered the powder coating formulation business. These new suppliers usually do not have the experience that the more traditional powder suppliers have. Look to deal with a supplier that has at least 5 years of experience in powder formulations."
- 191. "I work for a growing company in Saskatchewan, Canada. Currently we have two powder paint lines and one liquid paint line.
Our second line just came into operation last year and I have been on that line from the start. Lately we've been having problems with getting enough powder from the auto and manual guns. Some days there just isn't any powder flowing and it's hard to get good coverage on the parts. (We manufacture farm machinery.) We've checked the fluidizing and that seems good. We've cleaned out the hoses and the venturi pumps and the wearsleeves. Plus we've also checked out the stems going into the hopper. Everything seems good.
Something I've noticed is that when the manual guns are working fine there seems to be a lot of buildup on the tips. Then on the days they aren't working well the tips are clean, no buildup at all on the tips. Could this be a sign that there is an electrical problem? Everything is clean, the powder is fine. We can't seem to figure out why the guns don't put out much powder some days.
We are using a Nordson reclaim booth...10 autoguns per side and two manual guns. Thanks for any information you may be able to offer."11.06.16More
"Boy it seems that you looked at all the obvious areas of the powder feed system. I would have to assume that the transfer pumps are clean and operating properly, if you are refilling the feed hopper with reclaim powder at regular intervals. If this is not the case, then look at that.
Next, you should make sure that the feed rate is indeed changing or is the transfer efficiency (what ends up on the parts) is changing. The latter suggests that if the output for the guns is the same, then the powder isn't charging properly or the part ground has gone away.
The easiest way to check powder charging is to check the output current of each gun. This is not the voltage reading that you normally check. To read current output, check your manual for instructions. Usually, you push a button or pull the voltage adjust knob, and the current reading is displayed on the voltage meter using a different scale. The current is a measurement of work for the charging mechanism of the gun. You can have voltage present without current. This means that the field exists, but the charge is not transferred to the powder particle. Current readings should read between 20 and 50 microamperes.
If this reading is OK, then check for proper ground on the part to be coated. There should be less than 1 megohm resistance to ground in the entire circuit (part, hanger, conveyor, etc.). If this is resistance is above 1 megohm, then clean the contact points along the entire circuit. Burn-off the hangers, clean the conveyor, etc.
The other area where transfer efficiency can be effected differently each day would be environmental conditions (temperature & humidity). These will effect the rate the powder is pumped and charged. Normal limits for these can be obtained from your powder supplier (65-85 degrees F & 40-60% RH).
If you are still having problems after checking these parameters, get back to us with more information."
- 192. "We are considering enclosing a small area of a production line where a powdered food seasoning is applied. The volume of the containment area is approximately 10 cubic feet. The openings for entering and exiting the conveyor belt and other necessary openings total approximately 8.5 square feet.
Excess seasoning falls into the hopper located below the belt and is removed for reuse. Air is to be removed from the area below the conveyor belt. How much air flow will be required to keep the seasoning from escaping the control area? Removed air will be filtered and airborne seasoning will be recovered for reuse. The seasoning itself is a fine powder, small enough to pass through a U.S. No. 10 screen. Thank you for any help."11.06.16More
"Food seasoning may not react as powder coating does. However, for your information, 60 fpm is the air velocity that will control powder particles. All powder coating spray booths are designed with this value in mind. I'm not sure if the same air velocity will work for your application."
- 193. "I want to know how can I treat a piece of metal to get a strong coat using electrostatic pistol and powder paint (hybrid or polyester)."11.06.16More
"Pretreatment for metal parts in a powder coating system provides for corrosion resistance and not attraction of the powder. The only thing you need for proper electrostatic attraction is a good ground on the part (less than one megaohm), a properly maintained gun, and some control of the environmental conditions in the spray area (50-60% RH & 60-85 degrees F)."
- 194. "Is there anything to tell about the new phenomena named Thin Layer Powder Coatings? I am interested in whether the thin layer powder coatings now available are just developments of existing formulas (e.g. lower PVC, better flow etc.) or are they produced with new technology? By new technology I mean pigments with improved hiding power, a new way of grinding, new type of binder(s) etc. I hope you can satisfy my curiosity."11.06.16More
"The new thin film powder coatings are being developed with variations of two important characteristics. First is flow rate; the ability of a powder coating to flow smoothly at thin builds. Second is particle size; this is a function of the grinding technology. You make a valid point that as film builds get thinner, better pigmentation with better hiding power is important. I'm not sure if the technology has addressed this issue yet. Thin film builds in the North American Market are typically 1 mil. Powder coatings applied under this threshold have not yet been marketed."
- 195. "We have been using an emission factor of 3 lb volatile organics (VOC) emitted per 1000 pound of powder used when estimating the VOC emissions from powder coating operations. Does anybody out there have source test data on how much VOC emissions are emitted when powder coatings are sent through the curing oven?"11.06.16More
"Most powder coatings have ZERO (0) VOC emissions in the cure process. The only emissions that are exhausted from your cure oven are the by-products of combustion from the fuel source. For a while e-cap was on the EPA HAPs list. But even this component has been reclassified and is no longer a HAP. You should verify this with your powder formulator. You may have some different rules for California that don't apply to the rest of the universe."
- 196. "We are rebuilding a gear box that is in the environment of calcium and silica deposits which is destroying the current finish on the box. I would like to know if powder coating would be a possible finish for this box, and if so how thick would you put this on."11.06.16More
"Thickness isn't the important an issue as formulation. I suggest that you use an epoxy powder coating at 3.0 mils thickness."
- 197. "Looking at starting a custom powder coating business. Please advise minimum start up costs including all equipment (oven large enough to acommodate ski boat/car trailer, car frame ETC) and powder suppliers. Would prefer using sandblasting technique in leiu of chemical process. Do you have any reputable representatives on the west coast you can refer me to for start up?"11.06.16More
"Before you start buying any equipment, you should first determine exactly what you need by using independent consultants like us. We can help you identify your requirements and then advise you as to which manufacturers can best meet your needs."
- 198. "We have sub-contracted the powder coated sheet metal panels for a commercial air conditioning unit that we produce. The panels are made of galvannealed material with a zinc-rich powder primer and a polyester top coat. This combination was chosen to meet salt spray test requirements per ASTM B117 for a minimum of 240 Hours.
Our supplier is experiencing approximately a 20% rejection rate due to visual defects. Our requirements are no blister or blemish in excess of 3mm. Or no more than 5 blemishes, less than 3mm, within 1 square inch. The part must be viewed with the unaided (eye) at 24" in adequate lighting with 20/20 vision.
Is the problem we are experiencing more a function of the type of materials we are using? Is it more a function of the process controls of the company doing the powdercoating? Are our Quality requirements too stringent for the finish that can be attained using these materials?"11.06.16More
"You are doing way too much to work to obtain a 240 hour salt spray corrosion requirement. Galvanized steel, zinc rich primer, and powder top coat would be used for 2000 hours salt spray resistance. I'm afraid that in this case "more is not better". Each process step requires stringent process controls to be done correctly. The more you do to your product the more you risk creating a reject. Statistically, all the possible problems are compounded on your product. You should consider, redesigning your process (simplification) to accommodate your corrosion requirement."
- 199. "We are trying to coat chrome alloy steel tubing with transparent blue powder and a white powder. The steel tubing is stamped with its specs with a yellow dye. When we coat this product and after a little curing time the yellow dye bleeds through.
We have tried to solvent wash and sand the yellow off. Even though it appears that we get the yellow off it still bleeds back through our coating. What can you suggest? "11.06.16More
"The problem is "transparent" powders will not hide any defects on the substrate. Therefore, complete removal of this yellow ink is required. Solvent wiping will just dilute the ink an spread it around the surface. An aqueous cleaner with high impingement (mechanical action) can produce the best results. A light sanding with a fine grit paper should follow the cleaning. Contact a pretreatment chemical supplier for an aqueous cleaner (alkaline or acidic)."
- 200. "What publication would you suggest for me if I want to start a powder coating business but know nothing about it? I would also need to know the costs involved."
- 201. "What type of particle size distribution works best in a reclaim system? For example will a powder with an average particle size of 45 microns work better than a grind with an average particle size of 58 microns. Also, what is an acceptable percentage of particles less than 20 microns(fines) in size? I am looking for numbers that would produce optimum performance with regard to fluidization. At what point will the amount of fines significantly affect fluidization? "11.06.16More
"Powder coating reclaim systems are designed to accommodate a wider range of particle size. There is no single particle size that is best, although finer particles are more difficult to fluidize and pump. Powders are formulated and ground to a bell shaped curve that has a range of particle sizes form 20 to 40 microns. This range accounts for the highest percentage of the particulate. However, there are particles that fall out of this range (less than 10 and greater than 50 microns) but they are few in number. The problems exist in a reclaim system when the bell shaped curve shifts toward finer particles (i.e. 50% or more less than 10 microns). Below 5 microns and the filters have difficulty capturing these particles. Remember, smoke is 15 microns, so what we are describing here is real small stuff.
Powder coating systems need smaller particles to fill the voids between the larger particles. If smaller particles were absent, then your surface appearance will have more orange peel. Imagine building a stone wall with all the same size rocks. If you don't have small ones to fill the gaps, then the wall will have a rough surface.
Virgin powder mixed with reclaim will eliminate all reclaim problems. Most suppliers recommend a mix ratio of at least 50% virgin material. If your first pass transfer efficiency is too low, then this may pose a problem. I suggest you check your transfer efficiency and improve it to at least 50% and don't worry about the reclaim particle size. Particle size is difficult to measure and control anyway."
- 202. "Is there any Teflon powder-coating available? If so, please let us know the supplier's contact information."11.06.16More
"Teflon is a registered product name owned by Dupont. They would be the supplier of this material or have a list of authorized Teflon applicators. PTFE (the generic name for Teflon) materials are manufactured by various other powder formulators. Contact the Powder Coating Institute (703) 684-1770 for more information."
- 203. "Can you please supply any available information regarding reliable test methods for assessing powder fluidization. Is a test rig available, where from, etc. Thank you in anticipation."11.06.16More
"There is no "test rig" available to test fluidization. Fluidization is normally checked visually. The bed should have a simmering pot look to it. Boiling or no movement is unacceptable. There are devices (level probes) to measure the height of the powder within the fluidized bed (or hopper). Contact your equipment manufacturer for more details."
- 204. "I am curious to know if any current technology could be adapted to apply a powdered phenol-formaldehyde resin to wood strands. The adhesion would have to be such that the powdered resin would remain on the strand as it suffers about an 8' drop. In addition, the strand would have to be thoroughly coated on both sides. Any information on this would be helpful."11.06.16More
"Due to the lack of an earth ground in the non-conductive wood strand, it would not be appropriate to use electrostatic powder applicators for this process. Powder equipment has been used in a variety of non-finishing applications with some success. But this application probably will not work because of the eight foot drop immediately after application of the material."
- 205. "Does anyone know where you can purchase a powder coat that resembles a chrome finish or a alloy polish finish?"11.06.16More
"Sieberts has a material that simulates a chrome look. It looks best when applied to wire products (i.e. shelving). On larger surface areas it looks like a glossy gray coating. Sieberts also has a pretty good variety of tinted clears that can look very nice. Good luck in your search; but remember no organic coating (powder) will ever look exactly like an inorganic (plating) coating."
- 206. "I recently had my aluminum mountain bike frame powdercoated. I plan to have some lettering done on it. What type of paint should the painter use? What would be a good clear spraycoat after the lettering is done? By the way, where can I find a good explanation of the POWDER COATING process."11.06.16More
"There is a book that is available from us called "Powder Coating: The Complete Finisher's Handbook". It costs $75.00 US plus shipping and handling. If you buy it from us we can save you some money ($60.00 US + shipping). This book covers the entire powder coating process and will answer all your questions. I am the book's Editor and I am very proud of its contents.
Lettering over powder coating can be a problem if you don't know what powder was used. Compatibility between the powder, the lettering, and clear coat is important for adhesion. Find out what coating was used and contact the local rep from that company for suggestions."
- 207. "We are looking at powder coating high pressure aluminum gas cylinders. The cylinders consist of 6082 T6 / 6061 T6 aluminum alloy. We realize that aluminum alloys cannot be exposed to high temperatures for an extended period of time. What do you advise? "11.06.16More
"Powder coatings are cured using infrared technology all the time. Line of sight issues aren't a problem on such a symmetrical surface (cylinders). The cylinder will have to be rotated in front of the IR lamps to heat all surfaces. If you use this technology, the cure time is shortened to as little as thirty seconds. The heat won't penetrate the substrate (heat it through) in this short period of time."
- 208. "We are looking for a coating powder to encapsulate varistors (electronic parts). The powder should be flammable resistant (UL 94V-0). Where can I find distributors for such a powder - in Germany / - in the USA? It is important that the distributors can offer also a small package size (50 kg) because our consumption is low."11.06.16More
"The material used for this purpose is normally epoxy. However, you should discuss your requirements with a powder coating formulator. There are 75 formulators in the US. I'm not sure how many there are in Germany. For a list of the US suppliers contact the Powder Coating Institute (703) 684-1770."
- 209. "I am looking for alternative methods to improve the ground on a powder coating line. I have been informed of a system whereby the hooks hanging material "brush" by a grounding rod(s) just prior to, and during, powder application. Is such a device manufactured ? (the system I was informed of was a fairly crude homemade job).
Any information is appreciated as well as any other suggestions for improving grounding. Thank You."11.06.16More
"All grounding rods are homemade and usually crude. They are used as a last resort to provide a good ground to the parts being sprayed. All efforts to provide the ground through the conveyor and hanger should be made first. Ground rods can cause ungodly noise and dirt (iron filings) within the powder booth.
Clean your hangers and conveyor parts on a regular basis and you won't have to deal with this issue. One megohm (1,000,000 ohms) resistance to a known ground is allowable under NFPA code."
- 210. "I am looking for training material (videotapes) for painting operations. Do these tapes exist? If yes, would you tell me where I can get them. Thank you."11.06.16More
"The Powder Coating Institute and the Chemical Coaters Association both have training materials and video tapes. Contact them directly for more information."
- 211. "I use stainless steel 302 and 304 as trimming in a salt water tank, and the salt concentration is around 2500 ppm. The chloride causes the stainless steel to corrode. Are there any powder coatings suitable for my application?"11.06.16More
"I would use a high nickel content stainless steel first. A marine grade stainless steel can be very suitable for your situation. If you really want to powder coat this part, use an epoxy powder coating. This powder is the most resistant to salt water corrosion."
- 212. "Are there acrylic powder coats available other than a clear coat, and if so what is their advantage and major use? Also, can you suggest a primer that could be used to enhance corrosion protection and is compatible with a TGIC Polyester powder? Thanks."11.06.16More
"Acrylic powder coatings are very hard materials and provide superior UV stability. Zinc-rich powder coatings can be a very effective primer for TGIC polyesters. However, I would investigate better substrates (Galvanneal) and pretreatment (Zinc phosphate) before using a primer. These (galvanneal & zinc phosphate) in combination can provide up to 1000 hours of salt spray protection on a scribed panel."
- 213. "I am looking for a new source that can do powder coating for our business. We are sending aluminum dials to a coater and are experiencing quality problems. Our current supplier is not able to rack the dials properly and the racks cause marks on the dials.
Can you suggest some names of alternate sources that would be able to do coating on aluminum? The dials eventually go in to meters and gauges for the marine/automotive industry."11.06.16More
"Contact the Powder Coating Institute (703) 684-1770 and ask for their "Custom Coaters Directory" which lists over 50 job-shops ready to provide you their services."
- 214. "How is pre-painted metal affecting the powder coating jobbers in your area? When was this material introduced to the market? "11.06.16More
"Prepainted materials offer high quality coverage at a low cost. However, they do not have the same properties of powder coating which can outlast prepainted stock. Additionally, tool life can be reduced with prepainted stock (abrasion and dulling of punches an dies).
Furthermore, the raw edges of prepainted stock after shearing can be a problem on some parts. Prepaint stock has not substantially affected the powder coating market to date and has been around for more than 20 years."
- 215. "What companies do cryogenic grinding of paint powders? What do the polymer powders cost per kg typically? Where can I get a description of the cryogenic grinding process?"11.06.16More
"Cryogenic grinding is sometimes used in the manufacture of low temperature powders. This technology is employed by only a few powder formulators. Who is specifically doing this at this time is hard to say. We suggest that you contact the Powder Coating Institute, Alexandria, VA for more information."
- 216. "Is it possible to create a very thin (.001 - .0015") fluoropolymer film (PTFE, FEP or PFA) by the electrostatic powder coating process in a way that the film will not stick to the metal base material and can be removed from it?"11.06.16More
"PTFE powders can be applied by electrostatic spray to substrates at 1.5 mils or greater. PTFE powders usually need a liquid primer for adhesion to the substrate. Knowing these two facts, can it be assumed that a 1.5 mil coating of PTFE material, applied at 1.5 mils without a primer and allowed to flow into a continuous film be removed (peeled) to form a sheet? I don't think so, since the film would probably tear during removal. But it sounds like an interesting experiment to try."
- 217. "We are currently purchasing a complete used automated powder paint line. As we intend to do local work plus our own I am interested if there is an industry standard for pricing; i.e., time, per sq.inch or overall size. Any info on this would be greatly appreciated."11.06.16More
"Sorry, but all custom job shops price their work as any other business. They charge according to their market, competition, cost, etc. You are going to have to determine what price you can charge for your service to remain competitive, and make a profit."
- 218. "I know you'll think me simple, but I noticed a truck here in Melbourne advertising powder coating and I'm intrigued. Being an office worker, I've no idea what the process is. I remember once at a school meeting, we arranged to have some security mesh "powder coated", but what it is and what it means is beyond me. I know this sounds silly but I'm simply curious."11.06.16More
"Powder coating is a manufacturing process whereby an organic coating is applied to a substrate and cured to a durable finish. Parts to be coated are cleaned, pretreated, and dried before coating. The powder coating material, as the name suggests, is in particulate (dust) form. This material is applied by either dip or spray techniques. The parts are cured using heat, resulting in a very durable and high quality finish that resembles liquid paint without the solvent problems. There are several books on the subject. The best one is "Powder Coating; The Complete Finisher's Handbook", which is published by the Powder Coating Institute. Copies are available from them for $75.00 plus shipping and handling. We sell this book at a discount for $60.00 plus shipping and handling."
- 219. "We have some stainless steel pipes and valves located at the Cape Kennedy launch facility. They are corroding; some are developing minor pin holes. The items are outside and subject to the normal salt environment. Additionally, they are exposed to Solid Rocket Motor residue. They are washed off after each launch with fresh water. The fluid running through the items is liquid oxygen. The valves and some pipes can get below -300�F.
Is there some coating which can be applied. First preference would be without removing the items. The second would be to coat the replacement items."11.06.16More
"The best method for coating these pipes and valve in place is to use a system called "flame spray". The equipment for this process is sold by Plastic Flame Coat in Big Spring, TX. This process has been very effective at applying thermoplastic powder coatings on large objects that require a corrosion barrier. For instance, rail cars, water tanks, bridges, etc. I would suggest that you drain the oxygen from the pipes before you use this process. Contact them for further information."
- 220. "I am interested in restoring an '83 Harley Davidson. Some of the aluminum covers have been chromed and all covers have been in use for 15 years. Can these covers be stripped and powder coated successfully? If powder coated with a high gloss color should they also be covered with a clear? "11.06.16More
"Chrome plating can be stripped by an informed plater. Many powder coatings have high gloss characteristics that do not require a clear top coat. However, if you are looking for that deep depth of finish, like the old laquer jobs, a clear coat can offer that look, although with more orange peel."
- 221. "What advantage does powder coating provide over galvanized or painted plated metals in terms of resistance to weathering? What type of adhesive would be recommended to bond rubber or neoprene material to a powder coated metal object?"11.06.16More
"The advantages of powder (an organic finish) over plating or galvanizing (an inorganic finish) are all on the application side. Powder coating can be applied without the hazardous waste associated with the plating or galvanizing. However, organic powder coating, although superior to other organic finishes, will not perform as well as inorganic finishes. Knowing this, you should test powder coatings for the specific weathering, and any other performance characteristics, that you require for your product before considering a switch to powder coating.
As for adhesives, check with your adhesive supplier for an appropriate rubber or neoprene bond; that is an adhesive that will not degrade those materials. Most powder coatings are fairly impervious to most adhesives. Remember: you can always test the adhesive and powder coat for suitability before introducing the combination to full scale production."
- 222. "In Denmark the Powder Coating Companies have problems with yellowing of white coatings in gas fired curing ovens that have direct contact between the exhaust gasses and coated surfaces. We would like to know if this is a common problem in other countries, which parameters in the curing process affects the yellowing tendency, and what has been done to solve the problem? "11.06.16More
"In the US, direct gas fired cure ovens are exhausted at 12 air changes per hour, or higher, to eliminate yellowing of light colored powder coatings. Exhausting of the combustion gases is important for light colored powders used on high quality parts. If the exhaust rate is 12 or more air changes per hour, look to overbaking the powder as the next most contributory cause of yellowing.
Upon occasion, although rare, indirect fired gas ovens, electric convection and IR ovens, or gas fired IR ovens are used to eliminate all problems with combustion gasses. Be aware, that US manufacturers of white powder coated products such as fluorescent lights, appliances, etc. cure their products with direct fired gas combustion ovens without yellowing problems."
- 223. "Could you provide information on the powder coating process. I wish to apply this technique to my exhaust system."11.06.16More
"I suggest that you contact a local job shop that offers powder coating services. If you are going to coat your exhaust system, choose a silicone formulated powder manufactured for high-temperature applications."
- 224. "Looking for a highly reflective powder coat. Application will be on either aluminum or steel round bar(.50"dia)Must reflect light (i.e. traffic markers) Color either white or silver."11.06.16More
"There are over 70 suppliers of powder coating materials in the US. Most of these companies will have what you need. I suggest that you contact the Powder Coating Institute for a list and start calling them for samples."
- 225. "We are looking for a spring or finger rack manufacturer for racking light weight, short aluminum extrusions without holes (ie secured from the ends leaving minimal marks). We would prefer racks made of stainless steel."11.06.16More
"Call a plating rack manufacturer, like Associated Rack. They have the technology you want."