thought i would put my two cents in on this topic regarding the blasting with grit or sand and the smaller booth systems used. i used to work for a sanblasting company and i was asked several times to sand blast car panels including a pair of front aluminuim guards off some car from the 20's...
Anyways if its done right blasting shouldn't warp panels....i was taught to lower air pressure and sand feed and work in larger circle type motions at a 30-45 degree angle and to move over the area quickly as to reduce heat which is why most panels warp in the first place.
had the job of blasting a 2 door HQ GTS coupe once and the owner came in with me to watch what i was doing, he seemed happy with the work gave me a 50 dollar tip on top of the job cost...was stoked....
the smaller booth type units with the gloves you put your hands through are really good for like everyone has said use with small parts, i do suggest however if you are going to do alloy parts that you use a glass type grit instead of garnet or bead.m it looks like really fine sugar and does not pit the surface of the alloy as much as garnet does and brings it up perfect every time.
cheers