Dartin for Divorce
Its 15 gallons. Ive had it forever and got it for free
I had trouble keeping up with grinders with my old craftsman 30g (direct drive "rattler" pump).
I now have a husky belt drive piston pumped, two stage 60g and it will keep up, but only because of the start-stop to clear off debris and such. If it was a constant-on situation, I'd definitely run out of air with grinders or cutoff tools. Keeps up with most everything else though!
If I were you, I'd use the shortest and biggest diameter hose you can get that will work for your application.. Even if the end fittings wind up needing to be "stepped down". A larger hose helps get the most out of the compressor you have. Otherwise it takes more pressure to get the same "cfm", and direct drive pumps aren't the best at the higher pressures.
My old 30g had a hard time keeping up with an air ratchet while I used a cheap hose (one of those plastic coil style jobbers, they suck). I then went and got a rubber 1/2" hose and made a step down coupler at the tool end to mount a 3/8" quick attach - it made a bigger difference than it should have! Since then I try to keep the hose as big as I can to ensure max flow. A good quality rubber 3/8" hose also works well. I still use several for tools that need more mobility (1/2" hoses are bulky), and I use a cheap HF 3/8" hose for blasting work (don't want to ruin the good stuff) and it seems to do OK with that task.