Tri Mix of any use for Tig?

[robzr]

I have a 20 cf bottle of Tri-Mix (91% Helium 8% Argon 1% CO2) that I got for using with MIG welding stainless. Is this usable for TIG, any benefits of this over 100% Argon?

I think I can get full credit on the bottle if I trade it in, would any other mixes (helium/argon) or gasses (helium) be good to have on hand? Or maybe I can get a transfill pigtail and keep it as a backup/portable unit for Argon.

FWIW, I'm just getting familiar with TIG on (stainless) steel now, I'd like to do aluminum projects, and maybe even some copper.

Rob

[MAC702]

ANY CO2 is detrimental to a hot tungsten, but that is the lowest CO2 content of any Tri-mix I've seen before, most are 2.5%. I would say that it MIGHT be worth experimenting with, but it's not something you'd want to do on purpose if you had a choice. You really need an inert gas for most TIG welding, so argon does most things, and a 75/25 He/Ar is good for upper capabilites.

[Darmik]

Argon is the best for ms,ss,alu,
Helium is okay but thats about it i have never used a tri mix gas
i should have used a tri mix in school to see what happens

[Rocky D]

Helium mixes generally are used for aluminum, on straight polarity, and no thinner than 3/8"...it creates a hotter arc and will punch through thicker aluminum. I would think that your mix is used for automatic welding aliminum.

[Engloid]

ANY amount of CO2 is not good for tig welding. You will have trash all over your weld, and the tungsten will not stay sharp for even a few seconds.

Heil trailers used to use Argon/CO2 mix, and I went through **** getting them to change... buncha idiots!!!