We found powder peeling off parts. After talking to the shop supervisor he informed me that he had to put a second application of powder on some parts. We are using polyester, could you tell us the best way to recoat over powder? D. A
To maximize intercoat adhesion on a two-coat powder coating several steps should be taken:
First, ensure that there are no additives in the powder that can be an impediment to adhesion (i.e. slip additives, gloss reducers, etc.). Some powder formulations cannot be re-coated without severe adhesion failure.
Second, scuff sand the surface between coats for a good bond. Be careful to remove any sanding dust.
Third, do not allow the powder coated part to be pretreated by the washer a second time, as this will cause spotting and other problems. Rinsing with fresh water is perfectly acceptable.
Lastly, ensure that both coats are fully cured.