Shielding gas for S/S

[richardnadolny]

Hello
Not a welder, but have been known to stick a few pieces of metal together over the years. My question is, do you have to use the tri-gas mix for 304 S/S, or will 75/25 argon mixture do in a pinch? I'm welding a patent dipper to use for trotline crabbing, so it does not need to be pretty...it just needs to work. Any help would be appreciated.

[urch55]

Two gas mixtures are the most popular #1 Tri-Mix=(90% He/7.5% Ar/2.5% CO2) #2 C2 98% Ar/2% CO2. If you use C25 (75% Ar/25% CO2) you will have rust problems so it will defeat the purpose of having stainless in the first place...

[Rottguinness]

No Prob

I made grates for my grill using 75/25 and 304 SS rods. CO2 makes weld hotter and a little more spatter but works just fine.

RG

[Northweldor]

Since this thread was brought up again, and may be confusing, all of the above are correct. If you are using GMAW in short-circuit transfer on a non-critical job, you will likely be ok, but the gas of choice on a production run using spray transfer would be different as would the gas for GTAW. The choice of gas is dependent on process, transfer, and quality needed, but, "in a pinch", C25 wil do.

[Northweldor]

co2 is regular and better

Same wrong information as you posted in another thread! Doing some ignorant trolling?

[aametalmaster]

There is some gas flux core SS wires that are great and you don't need tri mix. Co2 or 75/25 will work just fine. They are avail in 2# spools so you don't need to buy a giant spool. Lots of shops are going to it since they already have CO2. We sell lots of it and I will get some 2# spools to sell. Its avail in 308 and 309 which should cover lots of different SS. I now work for my LWS and know first hand...Bob

[Tape]

Two gas mixtures are the most popular #1 Tri-Mix=(90% He/7.5% Ar/2.5% CO2) #2 C2 98% Ar/2% CO2. If you use C25 (75% Ar/25% CO2) you will have rust problems so it will defeat the purpose of having stainless in the first place...

There is some gas flux core SS wires that are great and you don't need tri mix. Co2 or 75/25 will work just fine. ...Bob

What about what urch55 it's saying? I just got done using stainless wire with C25 (75% Ar/25% CO2) installing 304 stainless muffler on my car, am I in for a rustfest?

[shreejisteel]

While a tri-gas mix is often recommended for welding stainless steel (like 304 S/S) to achieve the best results, a 75/25 argon mixture (75% argon and 25% carbon dioxide) can be used for welding stainless steel sometimes, especially for less critical applications where appearance is not a primary concern.

The choice of shielding gas depends on several factors, including the specific stainless steel alloy, the thickness of the material, and the welding process, you're using (e.g., MIG, TIG, or stick welding). In your case, since you're welding a patent dipper for trotline crabbing and appearance is not a priority, using a 75/25 argon mixture should suffice for basic functionality.

However, keep in mind that the weld may not be as clean or aesthetically pleasing as it would be with a tri-gas mix. It's essential to practice on scrap pieces first to get a feel for how the 75/25 argon mixture performs with your specific setup and stainless steel material.

Always follow proper safety precautions when welding, and if you have any doubts or encounter issues, it's a good idea to consult with a professional welder or seek guidance from a welding supply store for your specific project. Good luck with your crabbing invention!