Before we had a the 60 gallon stand up compressor, I used a 20 gallon 3 1/2 hp Craftsmans. That little sucker just won't die. It's got to be 20 years old and I did a lot of body work with it (running a DA, paint gun etc...). It did okay with the DA for 5-10 minutes at a time then I'd have to let it catch up.