My neighbor bought a 2-gallon air compressor at Harbor Fright - the Central Pneumatic model shown here.
In other words, when he uses the blow gun adaptor, he empties the tank faster than the compressor can refill it and after a very short period of time, he has to put the blow gun down and wait until the pressure builds back up.
Is this to be expected of an inexpensive compressor or is his unit defective?