TIG Mild Steel with Stainshield?

I have a gas bottle here that says Stainshield. I think it's mostly Argon, an Argon regulator fits the bottle. Not sure if this was for TIG or MIG. Anyway, can I use this gas to TIG mild steel?

Try it and report back

Peter

what does the manuf say ?
https://www.boc.com.au/shop/en/au/stainshield

Peter from Holland said:

Try it and report back

Peter

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I hope to this weekend. But since I don't know how to TIG weld just wondering in advance if I'll be able to blame the crappy results on the gas or if it's entirely me.

I’ve TIGed mild steel with 75/25 Argon/CO2. It’s definitely dirtier, but it’ll work.

My guess is that whatever comprises the “Stainshield” gas in question will be a lot cleaner than 75/25. I imagine it’s a tri-mix gas, probably mostly marketed for MIG-welding stainless alloys. Argon primarily, with Helium and CO2 making the balance, sometimes a tiny bit of oxygen instead of the argon.




Be safe




Jeremy

I found two different versions on Google, but both should work for stainless, from what I could tell. If you are a Tig beginner, you can ALWAYS blame the gas...

jermfab said:

. . .I imagine it’s a tri-mix gas . . .

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This one is Argon with 1.5% O2. I suspect there is enough oxygen to have a detrimental effect on most ordinary steels. It'll be interesting to see how it turns out.

With TIG the gas isn't just shielding the weld, it is also shielding the tungsten. My experience TIG welding with 75/25 resulted in a tungsten ruined the length extended from the collet, not just a bad weld. In fact I found this out when I was showing my brother in law how to TIG weld. It turns out it wasn't his technique ruining the tungsten it was the gas he was using.

You can give it a try but if you are trying to learn I would use the correct gas and remove that variable.

The Stainshield mentioned are active gases for mig/mag machines. The middle letter means inert or active gas.

TIG only uses argon($) argon/helium($$) or helium($$$$). If you put Co2 or O2 in the shield it eats the tungsten and reduces the weld puddle of some iron% and carbon% while leaving some iron oxide behind.

Good luck,
Matt

Gordon Heaton said:

This one is Argon with 1.5% O2. I suspect there is enough oxygen to have a detrimental effect on most ordinary steels. It'll be interesting to see how it turns out.

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I thought about that a bit more after I made my first response. Oxygen… and it’s oxidizing effect… will likely play hell with both tungsten electrode AND the weld. I would definitely assume I’d be dressing the tungsten regularly. Likely after every weld.

I do remember clearly the first time I learned that you could even make a TIG weld with 75/25. I came back to do some contract work in a shop I had worked at previously. The guy I trained to replace me had taken over and it was his shop at that point. I noticed that I was having trouble with arc wander and cleanliness and finally troubleshot the issue to the gas bottle.

When I asked my replacement why that tank was on the machine his response was: “you taught me to use 75/25 for mild steel…”

God knows how much mild steel he had TIG welded on 75/25.

Knowing that it COULD happen, I’ve done it once or twice since… but it has definitely been an “any port in a storm” option… definitely not ideal.




Be safe



Jeremy

there is 1.5% oxygen in it, it will react with the weld pool to make mig welding hotter and faster. but will make it dirtier to weld and 99% sure it wont turn out well for TIG.
in mig it works well for mild steel with the oxygen, my big mig i have a tri blend of gasses 92.5 argon, 5% co2 and 2.5% oxygen for thick metals.