First off you will not "get rid of the rust" by coating it in oil. Rust doesn't react with motor oil. If you ever heard that someone sprayed their under carriage with oil it needs to be thicker than used motor oil and its a preventative method its doesn't not react or get rid of rust. Now since you must live in an area where they use salt the rustoleum method will not work that well for you. Rattle can paint is cheap and the best "rust reformer" will not completely react with rust, all it really does is cover it up. My frame is pretty clean for a Chicago car and i wouldn't think of painting with and rattle can paint because it will just bleed through. If your really serious about cleaning up your frame there are a couple products. Por 15 and rust bullet. They are expensive but the formula uses actual chemical reactions to convert rust to a stable form that doesn't spread. A friend of mine who owns his own business uses rust bullet to paint old rusted grain silos. Like I said its pricey, around 600 or so for 5 gallons, I'm not sure of thr prices for smaller containers but in any area that uses salt I wouldn't trust many other products. My plan is to jack the car up this summer, wire brush the whole frame so its free of surface rust, and then coat the frame with black rust bullet. If you want to ask someone who has actually done it I believe I saw that toytec's shop painted a customers frame with por 15.
