Technically, CO2 isn't inert. So, when CO2 is used, they call it GMAW. Gas Metal Arc Welding. But, it is still used as a shielding gas, so I'll give you partial credit.BC Pneumatics wrote:CO2 is used in Inert Gas welding, hence being available at welding shot.
It costed me about $15 to exchange my 20lb tank last year. So, it shouldn't be very much. And just use the 5lb bottle instead of filling smaller ones. A 5lb bottle isn't that big, and you lose about 4 ounces or so every time you fill a tank since it needs to be chilled to accept more gas. Plus, you have to buy a scale and the fill station, plus at least a single small tank. If you had like a big K tank, then I could understand filling small tanks, but not when you have a 5 pounder. Hell, I thought about strapping an old 5lb tank to my back before for paintball.