Jim Cathey wrote: > I think it's about the same as the homebrew test refrigerant. > (Which I have been pleased with.)
Yep, I'm pretty sure it's propane/isobutane, sure enough I'm not going to look it up. I was surprised a couple of years ago when I called a gas dealer to buy propane and isobutatne by the refrigerant numbers (R290=propane R600a=iso) that they wanted several dollars a pound for refrigerant grade hydrocarbons. Furnace grade propane has a bit of H2O in it, as well as a nasty stink ingredient for leak detection, so it's less than ideal, but the idea of paying three figures for a 20lb can of R290 propane makes me choke.
