“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?”
“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.”