Dealing with Rust

(Also go read the "Buying Advice" section)

Best (only) way of rust proofing: remove and replace cancerous metal.

Second best: sandblast, degrease, (optional) acid etch with phosphoric acid, topcoat with zinc rich epoxy primer (3 coats). Many epoxy primers now have an etching component in them.

If you can spray the affected area, why not throw a finish coat on it? Modern basecoat/clear or urethane paints are very durable.

POR-15 is a decent product but it won't stick well to smooth metal.

There is much snake oil out there.

Rust proofing has a spotty record, especially if drain holes get plugged.

Marty