No such thing as a chemical cure for a mechanical problem.
If you have rust, cut it out and replace the metal.
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Yes the best solution is the elimination of any cancer.
However the problem is chemical. Rust is a chemical reaction. In particular its the formation of certain iron oxides and iron hydroxides. Chemically or electrochemically, they are reversible. However the steel will never be the same again. The hydroxides are a major problem - the flakey rusts that form tiny pockets where moisture is retained. These are a key part of the rusts that grow and grow.
Its the tiny pockets and the dust that will cause a film forming polymer to fail even if it seals out new moisture. However,
if there is a good surface to adhere to, a rust converter or rusty metal primer has a good chance of working when topped with a non-permeable coating.
