75/25 with Tig?

[aircraft]

roger is right. no.

Must use inert shielding gas for TIG welding to protect tungsten. Argon or Helium and mix of Helium and Argon are OK. Can't use CO2 in TIG shielding gas mix because it isn't inert and breaks down in arc to CO and O2.

[Mike W]

I know you are supposed to use 100% argon. But how would the 75/25 work on steel? Just curious.