I realize I'm new here and don't have much credibility, but I'll put my two cents in. My "second" job is refinishing guns. Any of the spray and bake finishes are light years ahead of regular spray paint. Some spray and bakes are better than others, but they are all (for the most part) formulated to stand up to cleaning solvents and be much more resistant to wear. Please don't spray your frame with krylon. In my experience, air cure firearms finishes are only marginally better than hardware store spray paint.
If you are on a budget you can get decent results with midway's wheeler engineering aerosol spray and bake finish.
As with any finishing, prep is 90% of the job. With degreasing being 90% of the prep.