I had some engine pieces lying around waiting to be cleaned. One day I saw a truck in the parking lot across the road depainting a Corvette so I asked the operator if he could do my engine stuff. He was using soda - baking soda powder, it is gentle enough not to eat the fibreglas body. He did my covers and the finish was excellent, no real abrasion of the metal but the crap and old clearcoat completely removed. He said they also did dry ice blasting, similar effect to soda but no dust problem (except for the removed old paint or whatever) and much more expensive.
The nice thing about soda is that it's water soluble, so washing the parts removes all the "abrasive" unlike bead or sand blasting where getting the crud out is a nightmare.
I agree with BODI, that the clean-up is a real PITA when using glass bead. Problem with most blasting material is it's too aggressive, and causes problems with aluminum alloy. The stuff tends to get stuck in the tinyest of places, threaded holes, and screws up finely machined surfaces, and can even distort the parts. I would recommend either the soda blasting as mentioned before, or
plastic media. I had my engine plastic media blasted, and it came out perfectly bare of all paint and crud, and the base metal was not harmed in any way. It will, however, mess-up any palstic or rubber parts if not careful, or when used with too much air pressure.
