I'm facing paint peel off / lack of adhesion problem in one sheet metal cover being used in automotive application. This part is a cylindrical cup where both surfaces - inside and outside are to be corrosion resistant. We decided to have MFZn-8G plating first and then the external surface is painted in assembled condition. After painting we find the finish not too good and also some peel-off problem. Is the green passivation (MFNz-8G) the correct one or should we go for another passivation with different thickness? Can someone please suggest the countermeasure?
