Tim,
Years ago, right after dirt was invented, I painted the aluminum body of a Super Modified
race car that ran at the "Indy of the East" track located in Oswego NY.
The paint products used for the project were all Rust-oleum products of various types.
There was available a primer for use exclusively on aluminum metal, and as I remember,
it was basically clear, but with a slight blue tint.
If you Google Rust-oleum paints, you will find that there are many products defined
exclusively for this application. Don't be confused by the paints that are advertised as
aluminum color.
Of course, any project with unknown variables requires a couple of experiments just to
be safe.
It was quite a thrill to sit up in the grandstands and watch that car in races, knowing that
I painted that good ole #37. That car was also the largest paint job I ever did.....it makes
model airplanes look so small by comparison. The finish looked great from that distance !!
Cheers.
Warren Wagner