Sandblasting Compressor advice please

[Keith Avery]

Wanted some advice from those with some experience in this area. My interests are in both restoring old machinery and woodworking. I have an old Quincy 108 compressor on a 60 gallon tank, it will put out about 6 cfm continously at 100psi and can pump up to 150 psi if used intermittantly. I also recently acquired a used duplex Quincy 325s with 80 a gallon tank. The motor on one was bad so only one compressor has a motor that is functional. My good motor 325 is putting out about 13 cfm on its 3 hp motor. It can take a 5hp and max's out at about 200 psi and 18 cfm at 900 rpms. So here is the question. Should I add a 3 hp motor to the other 325 and have about 25 cfm continous? I have compressor head, belt guards, hoses, starter, and pressure switch. I would just need motor, 2 belts and a pulley. Or I could sell the 108 and the 325 and just keep the single compressor. I could at some point upgrade to 5 hp if necessary but would also need a stronger starter. Would you guys keep both 325s or is 13 cfm gonna be plenty. I will add that a Quincy 325 is the biggest most impressive 3-5hp compressor I have ever seen, and having 2 sitting on one tank is both cool and ridiculous. Each head weighs around 285 lbs.

[Stephen Cherry]

Keith, I would say that the one compressor would get you sarted just fine. You would need to choose your tip size to accomidate the air you have available, or just wait for the tank to pump up. I've used a IR 7.5 hp compressor with a small sandblaster, and it was fine. With less power, you would just need to wait a little. The average woodworking machine would be blasted relatively easily. Quincy compressors are pretty robust, and make a similar IR t30 look small.

[Richard Wolf]

Long ago, before I started building stairs, I owned a sandblasting company. My largest compressor was a Quincy 850, which put out 850 cfm's at 100psi. I know I blasted large building, steel ships and bridges, but with sandblasting, it's all about cfm or volume, not so much pressure. Set yourself up for the most volume you can and size your tip to what you have, a small tip working continuously will get more work done than always waiting for your compressor to catch up.

[Scott T Smith]

but with sandblasting, it's all about cfm or volume, not so much pressure. Set yourself up for the most volume you can and size your tip to what you have, a small tip working continuously will get more work done than always waiting for your compressor to catch up.

+1, although if you are blasting in smaller batches increased tank pressure provides you with greater storage.

If I were in your shoes, I would opt for the 25 CFM combination. I have a 27 CFM compressor that I use for a glass bead blasting cabinet as well as a small, portable sandblaster, and it works well. For larger jobs (such as sandblasting a trailer chassis), I borrow/rent a large sandblasting rig with a 500 CFM compressor.