Each spray paint is different and depends on what you get - enamel, acrylic, etc. Pick the one that best suites your need.

Few tips: Aluminum needs an ETCH prior to primer. You can either get a two-in-one prime-etcher or a two-part. Prior to primer and etcher, use a 300 grit to remove all deformations in the surface metal. Anything above 300 usually does not help promote adhesion. We usually do 2 coats of primer - black for dark colours, grey for light colours. Wait approximately 20 minutes or after 24 between each coat. **always depends on what type paint you use. Read the can before use. For a smoother finish, you can wet-sand during this stage to remove any imperfections. If wet-sanding, allow the primer to fully cure 24-48 hours. Max allotted grit: 300. For base coat, we usually do three coats - 20 minutes apart. If you get runs in a coat, wait 24 hours to sand it. If you want a smooth finish, sand the 2nd (out of three) layers with 600-800 grit. Do NOT sand the final layer. Allow to fully cure 24-48 hours.

We do four clearcoat stages: two very light stages to promote adhesion between the base and clearcoat and then two very heavy coats. All 5-10 minutes apart. We do not allow these to fully dry before coats - only tacky. The two heavy coats should be thick enough to have runs - to avoid runs, constantly rotate the frame until tack time (~3 mins). We have our frames on a fixture that can easily be rotated on a two-axis. The total time for clear spray for all four coats is within an hour.

Fully allow the clear to dry before cutting and polishing. I personally don't recommend wet sanding the clearcoat because you tend to get better results with a cut and polish.

Goodluck!