Got a smallish tank with inert MIG gas. It still has gas in it. The label is gone, but for the part that says "non-flammable gas". I am pretty sure that it is MIG gas because the guy from whom I bought this tank, had only a MIG welder.
My first question is, I suspect that it is 75/25% mix, but how can I be sure of this.
My second question is, can I fill this tank with CO2 or do I need a special CO2 tank for CO2.
Thanks
i