Tuesday Welding question on a Saturday

[ORTitan]

I have some 304 and 316 stainless .062" exhaust tubing to weld. What gas mixes have you had the best results MIG weling with? I have been reading about "tri-mix" or 98/2 mixes. I have tried straight Argon which is not recommended. It had a weird arc and left a gray weld. 75/25 ar/co2 was also not pleasing.

I do have access to a tig machine, but am not skilled and this needs to be completed before I could achieve the skill.

 

[cj3a]

I would say it’s time to learn to tig or have someone do it for you.

 

[Gravy]

Tri mix

 

[kf4zht]

How much do you need to weld?

I wouldn't buy or rent a trimix tank for 1-2 joints. Just use argon and accept that it will suck some. A whole exhaust, I would learn tig. Tig stainless really isn't that hard especially if you have a machine with proper HF or lift start.

 

[stjames151]

I usually run 3% CO2, 2% O2, and 95% enriched methane for my exhaust, but it varies depending on the input fuel. Although, for tube that thin, im thinking you wouldn't want to run something that potentially in includes its own filler cause you definitely dont want to lay lumpy beads.



....Oh, and the trickiest part is getting the arc wave to line up with the variable gas flow.

 

[ORTitan]

Ok, so like, how many 7-11 chilli dogs are needed to get the 95% enriched methane?

I usually run 3% CO2, 2% O2, and 95% enriched methane for my exhaust, but it varies depending on the input fuel. Although, for tube that thin, im thinking you wouldn't want to run something that potentially in includes its own filler cause you definitely dont want to lay lumpy beads.



....Oh, and the trickiest part is getting the arc wave to line up with the variable gas flow.

 

[bdkw1]

Just hit it with mig mix. It will work just fine. No need to invest in another tank unless your going into production.

 

[Gatorgrizz27]

Back purge?

 

[bdkw1]

Back purge?

For MIG? I guess if you really wanted to.