How Do I tell If A Part Is Clean Enough To Powder Coat
Posted: March 21, 2019 By: MattM
Cleaning Metal Before Powder Coating
One of the most important steps of the powder coating process is cleaning and preparing an item before you even heat the oven up. A lot of times you won’t know your part isn’t cleaned well enough until it’s already too late and there are bubbles or fisheyes in the cured powder. Powder coated surfaces are difficult to strip so you want to save any risk of imperfections due to impurities in the surface. We decided to give you a few quick things you can do to assure parts are clean enough to powder coat.
- The White Glove (or Rag) treatment- Nothing tells the story of the surface of metal than a clean, white rag. If you wipe the surface with a rag and you come up with dirt or grease on it; you need to take the time to clean it better. Start with a degreaser or Paint Prep like Eastwood PRE. Sometimes a “clean” part can get dirt or oil on it just from handling it or sitting around the shop. Always give a a part one final wipe down with a clean, lint-free rag before applying your powder.
- The Water Test- If you’re worried about hidden oils still being on the surface you can do a quick, easy test of a part before coating it. pour water over the surface and see if it just runs off or does it bead up like a freshly detailed/waxed car? If water beads up on the surface you can be sure there’s an oily substance on the surface and it would cause an imperfection in your powder coated finish. After cleaning the surface with water you can spray the part with Eastwood After Blast to clean and etch the surface from flash rust.
- Pre-Bake Metal- Another sure fire way to get a part clean after the standard process of stripping old paint and dirt/grease is to bake the part in an oven and bring the part up beyond the curing temperature of the powder. This process will recreate the curing process and will “outgas” and impurities on the surface or in the pores of the metal. After the part has cooled down you can then follow the white rag and PRE cleaning method above to be sure its fully clean again.
If you follow these three quick steps you can be 99% sure your parts will come out with a beautiful powdered finish. To see all of our powder coating supplies visit our site HERE.