Mast paint
The critical part for any paint job is perparation of the substrate (the surface of the mast) for adherence. If the mast is anodized, it will have a "toothy" surface for the paint to adhere. If not, an etching chemical is needed to get a bond. Be a fanatic about following the manufacturers' instructions and avoid any surface contamination (including finger prints) I would use a top quality epoxy paint. Airplanes and aluminum boats are painted all the time and someone in a maintenance company would have a painter, who could give great advice for local conditions such as salt air etc. Maybe you wanted to do a more simple job, but in spite of the advertising, even Rustoleum will perform better if you pay strict attention to preparation.