hey mike, try using "dupli color" self etching primer or primer sealer from "xim". they both work very well, the dupli color is less expensive. you will need to scuff the aluminum with sandpaper or a scotch brite pad first before you prime.
Mike we use this product by Moeller which bought out the Tempo line after they closed. Anything that comes out of our blast cabinet gets this in the zinc chromate green.