I had my wheels coated last winter, and all of the shops I talked to offered prep services. The guy I gave the job to complained that he didn't like to sandblast aluminum, so he had them dipped instead. He claimed it was too easy to damage while blasting.
It is, but it depends on what medium you are using to blast. Ive taken chunks of a cast alluminum clutch cover once. That was using silica.
I am actually thinking about stripping hte paint of my rim as well since there are already large chips and paint missing from rocks etc. I was however, thinking of using aircraft grade paint stripper instead of blasting. I can do that at home instead of having to bring it and sneak it in to my brothers workplace just to do it.
