Colin, the guy I use has a huge setup, he mainly does commercial tanks and equipment. When he does my sheetmetel he turns the pressure way down but it still cleans at the speed u would use a spray gun, he also angles the blast head so the grit wont hit at a 90 degree angle. He's been doing it for alot of years. At first I was worried that my panels would warp but the guy knows his stuff.
