Mine is 21cuft, up to 200 PSI. The problem is the compressor can’t keep up, not the storage. I can run a nail gun all day. A brad nailer might make it come on twice in a day. But if break out the air gun to blow sawdust off something, it sucks the bottom out of the tank in no time. A plasma cutter melts the steel with an arc, then relies on butt-load of air to blow the molten metal out of the cut at high pressure and volume. Pretty much, any time it’s cutting, it’s blowing. That takes a LOT of air. I could possibly use one intermittently, but if I have to wait for the compressor to catch up, it’s hardly going to be any faster than an OxyAcetyline rig. Cleaner/less slag/cherries, probably, but horribly slow. I’d already have one if I didn’t need to replace a compressor I just bought.