Grateful11
Veteran Member
ZEP Industrial Purple available at Home Depot. Use full strength but don't let it on for more than about 2 minutes. It will take the paint off if left on too long.
You can dilute it 4 parts water to 1 part purple cleaner and it will work just as well.
BTW: Most of the cleaners of this type say not to use on bare aluminum or at least it use too.