Refill an Argon/CO2 cylinder with just Argon?

[cuban11182]

Looking at purchasing a used cylinder but it's for an Argon/CO2 mix and I'll be purchasing a TIG Welder.

I've never welded, but thought that I could purchase the Argon/CO2 used cylinder that is half filed and waste that gas to start the learning process. Once that was done I would set it up with a straight ARGON fill.

When purchasing a used cylinder I'm assuming that you look over the bottle for rust and corrosion and for an up-to-date hydro test correct? I'm also guessing they are good for what, 10 year?

Thanks

[welderShane]

Nope don't even think you can learn/use 75/25 for tig. Save yourself the major trouble and get the right gas, 100% argon. Yea they will have numbers stamped on them telling you the year and such.

[cuban11182]

Thank you.

[Stick-man]

You can purchase the tank. You can refill THAT tank with 100% AR. You just don't want to tig with 75/25 AR/CO2. So if the tank is cheap, buy it, dump the 75/25 or use it with mig, and then have it filled or exchanged for 100% AR.

[DSW]

Theres a sticky that shows what happens when you tryto use mig gas for tig. It's not good.

As far as the cyl, depending on the size, most places will swap it out for a similar sized cyl of a different gas no problem. If the cyl is out of hydro, they may just charge a small fee and swap the cyl anyways. Not many places fill on site any longer or send out cyl for refills, they just take yours and give you a similar cylinder with a current hydro and what ever gas you asked for and send you on your merry way.

Larger cylinders do cause some issues. In many places cyl larger than say 150cf are usually rental/lease cylinders, and some places are a bit more picky about swaps. I have an account where I get mine swapped, and they've never had any issues even when I took in cylinders I'd borrowed from a friend and are not on my account. Have cyl from same company to swap, have account, no problem, off I go... My guys don't even bother to check my hydro dates, so if I get a "new" cyl from CL or an auction, as long as it's smaller than 150cf or has a tag from them I'm good to go.