Using an air compressor for sandblasting metal or etching glass can be a lucrative profession or a satisfying hobby. Sandblasting in itself will use a large amount of compressed air in the process. By follow a basic procedure and understanding the usage, you can size an air compressor for sandblasting.
Gather all the pneumatic equipment you have or are going to purchase and find the total amount of air consumed you will need for each listed device. Make this list as you start the search. Although the greatest amounts of air maybe for sandblasting, chances are that you may also want to use other equipment at the same time.
Understand that most tools that use compressed air must also operate at a certain pressure. The pressure combined with the CFM will create the total supply that an air compressor can deliver. In general most tools will operate in the area of 90 to 100 pounds per square inch (PSI).
Realize that the orifice opening on a sandblaster nozzle will have a lot to do with the demands on an air compressor. The sand grit size also will have demands and the distance at which the blasting must take place from the sandblasting unit itself. In general, a sandblasting nozzle unit can consume in excess of 300 CFM.
Size the compressor with a 20 to 30 PSI oversize in the pressure regulator as a back up in the compressors receiver or storage tank. Most manufacturers build their air compressors on a rule of that for every one horsepower (HP) the compressor will provide 4 CFM at 90 PSI. So even a moderately sized sandblasting nozzle at 200 CFM may require a 50 HP power unit.
Remember that for great volumes of air generated in an air compressor there is also a large amount of water generated in that process. You should plan to add water removing systems or drainage as part of an air compressor system for sandblasting.