XtechX speaking for myself, all I do is use a metal prep / clean parts good /let dry /blow off lightly and use a good epoxy primer, prime your parts.If in dought try a small part and let it dry good and put some duct tape on it, press down hard and pull off fast to see if primer took I remember 30 years ago we blasted some lower fenders and used lacquer primer and after some time the paint and primer flaked off the blasted area paints have come a long way every painter has his ways
