Joe; Your idea of the refrigerator compressor won't work because of the oil problem you already noticed. It's the design of the compressor to pump a little oil as it operates, actually you would run it out of oil eventually. I don't know a lot about air brushing. But it sounds as if you could purchase an refillable air tank, (big box store). I've made them out of old "r" type refrigerant tanks, a 50 pounder is ideal, but I don't know if the make them that size anymore. And than you can fill them at a gas station, their compressors are usually big enough to give you all the air you'd need. Pedro Contrero