Sandblaster?

[MaxKlinger]

Ok, so how much air, in CFM, would I be looking for? How much would really be necessary for sandblasting? 16 CFM? 20CFM? 30CFM?

I realized from the beginning I'm going to need another compressor to do this. I'm just trying to get an idea of what I'm really looking for (and can I afford it?).

[FORDification]

My compressor is a 60-gallon upright rated at 13 CFM. I set up a large squirrel-cage fan blowing directly at the compressor pump while using it, to help with keeping it cool. I use the 40-lb Harbor Freight blaster, and with this setup the compressor will kick in after the blaster tank is about 20% emptied,
and I'll typically just start running low on air about the time the tank is empty and have to stop. That's about 10 minutes worth of blasting. Since I recover my sand, it'll take me another 15-20 minutes to sweep it up and sift it back into my recovery barrel, during which time the compressor is recovering.

What I'm trying to say is, this setup is probably the absolute minimum...and I'm probably working my compressor a bit hard....but it's worked for me so far.