I will be painting an exterior metal tank that has been previously painted with some type of thick paint. I have removed most of the paint w/stripper (Citristrip, works great!). The stripper left a lot of the original paint and primer. I have started sanding it down w/a RO sander to smooth it out and expose any rust (I am not trying to remove additional paint/primer or remove all rust). In some places there is leftover rust (pits/surface, not deep/heavy) and in some places the RO went through to bare metal. This is not to be a show piece, just something that won't bubble rust up in a couple of years.

My plan is to coat the tank w/rust converter (ex: Krudcutter). Then prime and topcoat. I'm a little unsure however whether a primer will be needed after the rust converter as most stated you can paint directly over it. Those places where the rust converter isn't needed will have the original paint or primer still there.

If primer is needed, water or oil based (recommendations)? If oil based, can a latex paint be sprayed over it?

Thanks!

 

Primer is always good to use, Rustoleum rusty metal primer with same brand top coat is a decent choice!

 

Latex paints have practically no rust inhibiting properties. You want to use solvent based primer and finish paint. I agree that Rustoleum primer and paint would be a good choice.