BTW you did say sand blasting... These are cheaper Harbor Freight jobs...

This is a cabinet style...
http://www.harborfreight.com/40-lb-c...net-93608.html
Requires a 5 HP compressor with minimum 12 CFM at 40-80 PSI

And here is a portable...
http://www.harborfreight.com/40-lb-p...ter-68992.html
Air consumption: 6-25 CFM

I use one like this...
http://www.harborfreight.com/portabl...kit-37025.html
Minimum air requirement: 3.5 CFM @ 50 PSI

Mine uses a lot of air... I run mine at a full pressure... It works great, until the pressure drops (few minutes) and then efficiency drops and use more air. Just giving you an idea of what air a sand blaster uses... Probably the highest air using tool. Btw at the moment I have a medium compressor.