Please help! I am having problems getting a second coat to stick to a cast aluminum timing cover. I shot columbia’s OGF primer for a first coat. The second coat is columbia’s hemi orange, if I can ever get it to stick. Another part shot (minus the primer) with the same powder turned out great. I have blown the cover off twice now after getting amazingly crappy results. I am using the hypersmooth gun, if that matters. Also using a bolt threaded into the cover for ground attachment. Any suggestions would be greatly appreciated. Thanks!