Use something other than sand if you're planning to blast sheet metal. Getting all the ripples out of a large flat panel like a bedside or a door after sandblasting will give you ulcers and make all your kids be born naked. Glass beads or other soft media work a lot better than sand on sheet metal. Sand is OK for heavy metal like a frame rail, rear end housing, etc.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!