My latest realization is that you can compensate for low cfm with tank volume, to some extent. Feel free to correct this. :)
What are some good (read: safe *and* free) options for makeup tanks? Propane -- as in BBQ? Oxygen? Acetylene? Others? I see many substantial-sized tanks in the dump that look neither Ox nor acet, thicker than your 5-ft tallish Ox tanks. Iny idear what these are?
One problem I can foresee is finding/making adapters to these tanks, as I'm pretty sure there are no standard plumbing threads, no adapters that I am aware of. How does one attack this problem?
I hesitate to have welding done on a tank, altho I think with piddling 120 psi air in an oxy/acet rated in the 1,000s of psi, mebbe welding "welded couplings" is not so dicey.