" writes:

How about nylon tubing? This is similar to what I use:

http://www.wicksaircraft.com/catalog...hp/subid=1745/

425psi working pressure, 1700psi burst, it connects easily with brass
compression fittings and it's flexible making routing easy. All for
$0.91/ft.

There is also DOT air hose used in trucks/buses with air brakes. You can
buy it at any heavy truck dealer and you can also get compression
fittings. The 1/2" diameter should carry enough air for the average shop.

Brian Elfert