"Mike Marlow" writes:


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.


Holy Cow Brian... $$$$$$$$

I just did a quick search online and found 1/2" DOT air line for 71 cents
per foot. This was at a street rod place, so a truck dealer should be
less.

71 cents a foot is a lot less than copper. don't know what black pipe
goes for these days.

There is a 500 foot roll on ebay for 35 cents a foot plus shipping.

Brian Elfert