Got a SS welding question...

[rick]

I need to mig some flat bar & angles to my stainless rigging to mount a few things ie., fuel pump & filter, gas tank, battery tray, etc.. I have a little Lincoln Pro 135 welder with a bottle of 75/25 argon/co2 and a bottle of 100% argon.

Pretty sure that neither bottle is best to mig SS, but just wondering if I can get by with either and which one might be best.

Appreciate any/all advice.

Rick

[unforgiven11B]

The 100% Argon will not weld good. If it was me and those two were my choices I’d use the 75/25, it will rust but not much and not like carbon steel but the CO2 introduces impurities should be no problems as it’s not a structural piece from what I gather. With CO2 run your machine 3-5% higher

[Whiskers]

The correct gas is a tri-mix. 90% Helium / 7.5% Argon / 2.5% Co2.

[Gladesman06]

The correct gas is a tri-mix. 90% Helium / 7.5% Argon / 2.5% Co2.

What Whiskers said is correct. With that said yes you can use 75/25. I use it all the time to mig weld stainless. It's definitely not the best option but it will definitely work.

Like Unforgiven said, make sure you turn your machine a little hotter and run the flow of gas a little more when using 75/25 on Stainless.

[Smuggler]

The 75/25 will do the job just fine. I built witchys whole stainless rigging with it because at the time they where out of my preferred stainless gas (98% argon 2% CO2) and I refused to pay the outrageous price for the helium that's in tri mix. However to me it seamed the 75/25 got the metal much hotter then my 98/2 does. You'll be fine just don't weld a lot at one time in one area without letting it completely cool back down and this will keep the warpage down.

[John Fenner]

C25 works, tri mix gives a blonde weld and cleaner appearance.

[rick]

Appreciate the help.

I was thinking about buying a high dollar bottle of that tri-mix, but spent the money on a tig welder to go with that bottle of argon instead. I'll either mig with the C25 or tig with the argon.

I tigged a lot of aluminum in my younger years at work, but that was when I could see and had a real steady hand. We'll see how that goes at 61 lol. Might take a beverage or two to help me keep that tungsten out of the puddle

Rick

[Slidin Gator]

Be a lot easier to train up a couple of them grandkids, probably quicker too. That way you don’t have to set the beer down and try figuring out where you set it.

[hdsadey]

Just finished up tiggin my cage and rigging! Man that stainless moves A LOT with heat!!!! 100% argon for shielding. If you got a sizable chunk of aluminum or copper that you can visegrip to the tubing it'll help act as a heat sink and reduce the warping. After I'm using pickling paste to clean up the weld discoloration and prevent corrosion.

[rick]

Looks good hdsadey.

Those tig welds look cleaner than the mig welds on my rigging. Might have to consider that pickling paste myself.

Rick

[hdsadey]

Thanks Rick! Welds ain't as pretty as I'd like but they'll do the job. Pic after pickling.

[kwanjangnihm]

hdsadey cage looks good man! what gauge is the wire on the cage?

[hdsadey]

3/16 sir spaced at 4 inches

[Prototype]

Rick, Maybe too late but I'll give it from knowledge and post use.
100% argon is safe and corrosion friendly to a possible salt use boat or rigging. Assuming it's maybe polished welds and such? 75/25 also works but pits rust in a couple years. Tri-mix is freaking grand to weld and cleanup, but again deposits co2 into the weld in a corrosive environment!
I don't see the use of rig close to or near salt or corrosives so most don't know what gasses do in following years?
It's not expense in my opinion at all..
But great point to gas used on every single weld that will rust pit if co2 is used in any combo of single or tri mix to exposed corrosives such as salt.
Yeah my ladies drink that much patron for cloths to fall off with a salt ring!
100 % argon if at all possible to retain all that initial work to weld and polish looks!

[Sniper]

Been A welder in the Aircraft Industry for 43 yrs and FAA Certified on 8 different metals, we tig everything and I agree with prototype we use nothing but 100 % Argon if you can get a gas lens for your cup on your tig machine it will give you a beautiful clean weld

[unforgiven11B]

He didn’t ask which gas to use for stainless or say he was GTAW anything. Rick stated given this equipment and these two gases which should he use. Out of the two stated gases and his Pro Mig 135 the C25 is the best choice. Obviously if he was going to TIg it 100% argon is the right choice. Had everyone answered the question asked and not throw out there opinions this thread wouldn’t have drifted from the original question.

[Murdogg]

E312.................