painting aluminum

Not sure if this is the right place to post this, but since you guys might know about this kind of thing, here goes. I bought a stoplight off ebay a little while back, and it is made out of cast aluminum. It needs to repainted, and I sanded a small part of it down to the metal, its had about 5 or 6 coats over the last 40 years. My question is, what do I need to do to it to prep it? The freshest coat of paint on it (still pretty old) is in pretty bad shape. If theres a better place to post this on AF, please advise

I think it goes for the same thing as diecasts... Someone correct me if Im wrong.. Buy a flat color (I.e. flat white, flat grey, those are the best for light colored projects which is yellow in your project) spray paint and prime it with that.. I would say about five coats.. Then get the shade of yellow you want for the stoplight and paint about 6 to 10 coats on there then get a clear coat and 1 or 2 coats and Wa-La!! Its a stoplight!

but will I need to sand at least some of the surface paint off before I prime it, or should I get it chemically stripped or what?

Just paint the flat white over the paint thats on now... Then smooth out any thing w/ sandpaper after each coat dries

Its hard to say where it should have been, we have an Auto Painting subforum in Car Detail under Cars in General.

Anyway, Prime it with some high build sandable primer. Then shoot with the basecoat, then clear.