I have a small part that is 6061 billet aluminum, polished and very pretty. Problem is I want it black. What can I paint it with? It does not have to be perfect, but it needs to be weather resistant. And should I rough up the polish or...? edit: BTW this is an electrical switch and I cannot disassemble it. I thought about POR, but I don't know if it will stick to nonferrous metals.