I would not sand blast aluminum!

too easy to make peeks and valleys in the aluminum that will oxidize later on and make it
look worse faster, plus you will need to sand to make it smooth again. Best is paint striper if your going to remove the paint...
spray on, scrape off... toxic stuff so delute it if your going to flush it down the drain

LOTS!... fish die easy from that stuff
(humans too

) anyways... if you sand, remember one thing. Aluminum contains oils in the metal... you need to clean it with
Methyl hydrate before you apply primer. A zink rich primer is best... or an etching primer for aluminum. Then top coat with paint,
I would use a durable paint (urethane), but if you don't have spray equipment, your left to a rattle can

should still look good.
-Rebel