Inconsistent Results

Question:

I have recently started a small powder coating business and am having trouble figuring out a few problems. On some items I am having trouble with bubbles or a wrinkled look of cured parts—some of the parts turn out perfect though and I am using the same process on both parts. Another problem I am having is a grainy or dull look on some parts, and again some parts turn out fine using the same process. Could it be that the parts are cooling too fast? Should I let the parts cool in the oven to a certain temperature before pulling them out?

I am also having some trouble with fish-eye spots and thin spots in the powder. I have noticed the spots more on some of the parts we have done. I look for them while spraying and everything looks perfect but until they come out of the oven. M.G.

Answer:

Most all of your problems (except for the light coverage) is caused by contamination of one or more items. You first must find the source(s) of this contamination and then stop it. Things to look for are: Oil or water in the compressed air, solvent in the cure oven, airborne solvents, silicone, chemicals, etc. in the surrounding area and lastly contaminants on your personnel . Good luck in isolating the source and removing it.