“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?”
“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”.”