I picked up an oxy/acetylene tank set for free at an estate sale a few years ago, oxy tank was a K size and out of date. Talked to 'my guy' at the local welding supply about converting to argon and he was amenable to it, took a while but only cost me around $80 for test, new valve and fill.
For some reason no one wants anything to do with the big acetylene tank though, not that I really need it...
Around here most companies won't sell you anything over an 80cf, though I've heard some will do 120's.
Never get a straight answer as to why, just cuz...
Earlier this year I ran across a nice deal on an idealarc sp-200 mig, big beast for what it is but for $400 came with two partway filled 120's, one 75/25 and the other straight argon. Also came with a nice spoolgun, regulator, tips, helmets, etc in addition to a pile of unrelated misc stuff, tools/tooling.
I'm due to fill the 120 argon so I'll soon find out what the $'s are these days, goes up a bit every time it seems.
Have a 60 with 75/25 and an 80 argon and just fill them myself off the 120 and/or K tank as the bigger tanks have always been a much better deal to fill.
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