Welding Tips and Tricks

Hey guys I've welded standard steel all my life and now I am thrust into a spot where I have to learn how to weld Stainless, specifically cast Stainless. The last welder before me just used TIG on everything. I did some TIG on a cast Stainless part last week and I think it turned out ok.

But I would like to setup my MIG machine to do it. I am welding on 1/4-1/2" cast Stainless, sometimes 316L, sometimes ASTM A743 GR CA6NM. Possibly others. The old welder told me he used Tri-mix 90-Helium, 7.5-Argon, 2.5-CO2 with spray arc on the 316L. However according to Millers website it says Tri-mix is for short circuit and I need a 98-argon, 2-O2 for spray.

I currently have nothing but 75-Argon/25-CO2 and I'd like to know what gas or if I need 2 what gasses to order.

I think you need the tri mix or 95-5.

my book here recommends 38% helium, 2% co2 and 60% argon.
that will handle short and spray for 1/2' or more.

In Australia we have Stainshield heavy and light... (proprietary names) oxygen, carbon dioxide and helium in argon in various parts depending on the thickness of the material you are working with.

You need a 95 argon and the rest is usually co2 maybe some 02 I use 95-4-1 argon co2 02 mix for everything it's a little more but welds clean you can spray mild and thin ss with this mix it's an all purpose blend so I just use it when ss needs repair all I do is swap wire just remember it's hot so thin mild needs to be backed off

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