I agree with Pugly. It is primer sealer that should address your needs.
My advice is to go down to your local auto paint supply store. I don't mean a NAPA-type store, I mean someone that specializes in body supplies.
Talk to a good counter man (this usually means an older guy - in my experience) about your application. There are so many options out there, he should be able to make a sound recommendation for you and his advice is FREE!
