Help -- weld mild steel with Tri-Mix or Argon

[rgentry]

For reasons that are not clear to me, our MIG welder has just been set up with a full bottle of pure argon and another with Helium tri-mix. What I mostly need to to is weld mild steel. I know that the argon is for aluminum and the tri-mix is for stainless steel (which we almost never encounter). What should I use for welding mild steel?

Given that I need to use the tri-mx up, can I use it with mild steel? Any suggestions on how to change the voltage and wire-speed settings from the suggested argon/CO2 mix?

Thanks.

[urch55]

Gentry. Use neither one. If you are sure you cannot use the shielding gas that you have. Trade the bottle back in and get some gas that you can use like for mild steel Argon/CO2 or strait CO2 but if you use the CO2 you will need a special CO2 regulator. So I would just use the 75/25 Argon/CO2 mix.

[rgentry]

OK. Not what I wanted to hear but good advice I suppose. We are a bit short on $$$ right now, and would like to use what we have.

[urch55]

OK. Not what I wanted to hear but good advice I suppose. We are a bit short on $$$ right now, and would like to use what we have.

It should not cost a thing. I have changed bottles from one gas to another and it did not cost me anything. But I relize not all LWS are the same. It would not hurt to ask. Who ordered it in the first place?, maybe it was just a mistake no big deal. In fact you should get money back because tri-mix cost more than C25, at least where I am located.

[rgentry]

I just talked to my boss and he said the same thing. We have not used any of the gas but it was delivered 4 months ago! Thanks again for your help. RG