For Baked Finishes on metal -- Yes, it can be done but it requires great understanding of surface prep and specialty coating products. Do NOT try it unless you can spray automotive paint on cars. If you can, then you would have chance.
For Fiberglass, we have had great success using Bio-Control Prime & Seal followed by 2 coats Graffiti No More Paint (like on PIER 39 in San Francisco). It take lots of sanding, cleaning with Wax & Grease Removers and spraying of the primers Topcoats. Finish is eggshell.
