Originally Posted by Warhammer
Interesting.... What is the minimum generally needed?
You don't have to run pipe to remove the water. But, it really helps and saves your tools. Run as much as you feel comfortable with. The larger the compressor the more you should run because it is the compressing of the air that causes the moisture as it expands through the pipes and rusts out the innards of your tools or comes out in the spray of your paint guns or the exhaust of your tools.
Take your compressor run a air gun and spray into a jar for 10 minutes or so and see how moist it is in. Might be a good test to prove we are correct. I am sure someone has a better proof test.