A: I wouldn’t. While there are special epoxy coatings made for coating metal (notably beer cans and paint cans), they are not the same thing as the hobby or marine epoxies available to you. There are, however, specialty coatings specifically for dealing with rust that are widely available.

You mentioned using Rust-Oleum, but that is a brand under which many different coatings are sold. That does not assume that you used the right product. Personally, I think that’s the key to this problem. The line you want is Rust-Oleum’s Stops Rust line, which includes, among other offerings, such things as Rust Reformer, which instantly converts rust to a non-rusting surface; Rust Stripper, which as its name implies, removes rust; Rusty Metal Primer, which can be applied to already rusted surfaces; Clean Metal Primer, for clean metal surfaces; and a variety of protective enamels in colors, textures and clear.