SoTexRattler

R-22 does an excellent job of degreasing the interior of the DAC (Dispose-A-Can) that any moisture plus any acidic contamination really makes that bare steel rust quick when exposed to air. The DAC's are actually quite clean and dry straight from the tank mfgr but some of the foreign mfg'd sources of cheap refrigerants have a little more residual trace acid in their product. Add a little moisture from an air compressor, and voila'!...Rust.
BTW, The old black **** DAC's would easily work for refrigerant recovery(or air tanks)and therefore the powers-at-be fixed that... All the new green **** DAC's now have a permanent check valve built into them to prevent backflow or re-use.
Some of those older ones that got used for recovery of some contaminated refrigerant from a previous hermetic compressor burnout would REALLY rust up when used as an air tank afterwards.

K.

Jfaulkner

Acutally a small shot of propane in an air conditioner system does wonders. Too much though and it freezes.

SoTexRattler

I think propane's vapor pressure is more like R-12 than R-22. Not near as high a vapor pressure as R-22.
Some of the "drop-in" car A/C refrigerant replacements for R-12 were propane & a few other LPG's blended to get the exact vapor press of R-12. They did work, but with that much LPG components in the blend, it was awfully hard to get away from that pesky flammability problem...
Can you imagine a slight leak of LPG in the evaporator and going out to your car and unlocking the door and the domelight comes on? BOOM!!!!

K

P.J

I happened to see a rack in the Hardware store today, it was full of those new(er) OFPD (overfill prevention device) valves. The pressure relief on the backside of it said "Do-Not Adjust--375psi" I don't hink you have to worry about blowing one!

Bart Timothy

You're right it's r12 and not r22.

93w250

I took an old 20lb tank and made an inflator out of it. Replaced the valve with a 1 inch ball valve to a piece of copper pipe flattened on the end. It works great. It has a fitting so I can use it as an air tank also.

Haulin_in_Dixie

Propane is used regularly as a refridgerant especially on old vehicles.

Dieseldude4x4

Can yo say "kaaaaaaaaaaaaaaaboooooooooooom".
Yes, I thought you could.

Haulin_in_Dixie

But does not change what I stated... I don't run it