After being blown off with compressed air the fender can be primed. The primer we are using here is a high build 2K with a 2.1 VOC rating, which is the max for us here in California. At press time, all of Summit's primers had a higher VOC rating so they couldn't ship them into California, but now they fall into compliance. Back to the primer at hand, this stuff is designed to go over bare metal and still be a high build. It was mixed 4:1 before being poured into Vic's DeVilbiss PRI gun with a 1.8 tip. He applied 3 heavy coats, 10 to 12-inches from the panel being sprayed with a 50-percent overlap on each stroke/pass.