i have been painting parts under the hood. air cleaner etc. every part i take off after i get them down to bare metal i primer then paint. my question is the block has about 90% paint an only a few rusted spots do i have to primer the whole motor or just clean up the spots and primer them.
I've never used primer on an engine. I always use that rattle can engine paint from Plasticoat and never had a problem.
I agree ... I did primer my valve covers first ... but nothing else. The paint actually chips fairly easy on the valve covers now so I probably shouldn't have primered them either ...
We never primered an engine either. Just degreased it as good as possible and sprayed it with rattle-can engine paint. Now the valve covers and aircleaner cover we stripped and primered and then used the rattle-can paint on them too. But we also clear-coated them with urathane clear and they have never chipped or peeled.