I had send my coating board to the test lab for adhesion coating test. 3 times send, the result 3times fail. The coating chemical use is Humiseal 1B31. The process is clean the boards at washing process use the Vigon A200 saponifier mix with DI water, Test the cleanlines of teh boards with Omega meter, Result pass, then kept the board at baking for 6 hour with temp 85 degC, finish that then coating the boards use the PVA coating machine with humiseal 1B31 coating material. cure the boards with PVA curing machine. Upon finish that process the I send teh boards to the 3rd part test lab on the adhesion coating test. the result come out from the test labs is all my boards was fail and the coating was peel off.
Any one knowing what's teh problem to my process ? and how to solve it ?