I am new to sandblasting on my own but have an opportunity to get into some potentially big money I will be bidding on sandblasting oil tanks and rigs. But I don't really know the going rate or what medium is required to use on the tanks. I know it's not sand. And what do you do with the spent material etc. I'm thinking 7-8$ sq ft. 400 CFM. With 3/8 or 1/2" nozzle. Any advise? Pro are you here. You seem very knowledgeable.