[QUOTE=Iwanttolearn]Why am I buying an undersized compressor? QUOTE]
Go back and reread my 1st post. The only thing that counts is the output of the compressor. Determine how much air you are going to use and buy a compressor that will produce more.
A 60 gal tank is all you need for a reserve if the compressor is sized right.
A 7" air sander will require 11-12 cfm
22cfm will run a bead blaster or a very small sand blaster satisfactorily with occasional rests to let the compressor cool.
My 105 cfm Jeager just bearly keeps up with my 90lb pressurized sandblaster