If you want something that's available in a rattle can, try Zero-Rust. It claims to "neutralize" the rust and create a barrier against further rusting. I primed my whole truck with it. No far, no rust thru.
I bought it at an auto paint supply store. You can go to these web sites:
www.zero-rust.com www.zerorust.com One of them has an 800 number you can call to find a dealer in your area.
Good luck,
