Rattle can primer?

Southern Polyurethanes sells their epoxy in quarts (1qt part A, 1 qt part B). I bet you could get them to sell you less than a quart, like a couple pints. Then you can mix what you need for the job and save the rest for other jobs. Prep your metal as much as humanly possible and brush it on. Lays down smooth with a gun and probably would lay down nice with a brush. It is etching epoxy. Rock solid foundation coat and excellent quality.