Clean the aluminum thoroughly with soap and water
Remove grease, oil, and dirt with a degreaser or rubbing alcohol
Rinse and dry completely
Sand the surface lightly with fine-grit sandpaper
Wipe away all sanding dust with a clean cloth
Apply an aluminum-compatible primer
Let the primer dry fully
Apply thin, even coats of paint
Allow each coat to dry before adding the next
Add additional coats as needed for full coverage
Let the final coat cure completely
Apply a clear protective topcoat if desired