If you are the point of painting, you shouldn't have any bare metal showing. Blow the vehicle off, tack and apply your epoxy sealer. They you are ready for your high fill primer for blocking.

You should never have bare metal when it is time to apply the paint.

Frank

No better smell than that of fresh paint. I've been building and painting cars/trucks for 47 years. Not gonna stop now.
http://www.coxcustomcars.com/