I have been blasting for years many whole cars large parts . Never have seen warping . I use a large compressor { compressor size has nothing to do with warping its the pressure } I use about 110 LBs With alarge Maco Blaster . Have done panls on a 1916 Overland , 1972 MGB this summer . I It is dirty job , I use a pressure fed helmet off a second compressor . Kings32