Originally Posted by 001mustang
1/2" copper will be sufficient if you use only one tool at a time. You can run a healthy sand blaster or paint gun using the 100' 1/2 Cu line. You can run 3/4" Cu if you have overkill tendencies.
If you run one tool at a time you will be hard pressed to use all the air a 100ft 1/2" line can provide, regardless of compressor size..
100' 1/2" pipe will flow 54 SCFM at 100 PSI with a 10% DP.