Sizing a compressor that keeps up with the tool

A compressor is sized by the tool with the highest continuous demand, not by the tool you use most often. An impact wrench takes short bursts; a sander takes everything the pump can give, without pause.

Receiver volume buys time, not air

A larger receiver lets the motor rest between bursts. It does not increase the air the pump produces, so a continuous tool empties a large receiver as surely as a small one.

Oil-free where finish matters

An oil-free pump carries no oil into the line. For spraying and for inflation that is the difference between a clean surface and a day of rework.