Author Topic: Stainless mig welding  (Read 234 times)

Carpenter84

Stainless mig welding
« on: November 19, 2023, 08:11:50 PM »
I only ever tig weld stainless. I recently did a very large fixture job which resulted in a solid week of stainless tig welding. Turns out that same job is coming up again in December. I know you can mig weld stainless. I need to do that next time to cut the weld time down.
Has anyone done enough stainless mig welding to offer any suggestions or opinions?

I am running an old dinosaur Airco large transformer multi-process machine. Its a big old beast that I have Frankensteined into a half decent production machine. Capable of around 160 amps DC mig. I also have the matching high frequency unit.
I have any and every gas and accessory available at the order desk.

So, whos done it? And what do I need to know?
Ill ask the gas supplier what gas I need. Im very familiar with my machine and every type of welding its capable of - but Ive never mig welded stainless. I know cleanliness is going to be key. Ill also ask the supplier what wire to use.

Im looking for more experience based suggestions. Is there a certain technique to use? Is there anything I need to watch for? Are there certain products I should have on hand?
Believe the stainless is 304. It will be coming in 6mm sheet (form bent), 1/2 & 5/8 plate I will machine to necessary dimensions. The last order tig welded just fine (as fine as a butcher was capable of) but Im a slooowww tig welder.
Thanks
Shawn

Terrywerm

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Re: Stainless mig welding
« Reply #1 on: November 19, 2023, 10:30:42 PM »
I have done a small amount of MIG welding on stainless but a lot of TIG which is just slow by nature, but a much higher quality weld in my opinion.


Anyway, the little bit of stainless MIG that I've done is not enough to qualify me to really say much on the subject. I can say that it would be faster, but that is about it. 


 :coffee2:


 
Terry

Making chips with old machines!

Carpenter84

Re: Stainless mig welding
« Reply #2 on: November 19, 2023, 10:56:25 PM »
This is by no means structural or pipe welding. They are assembly fixtures for the auto industry. Likely to be abused and welded back together countless times.
Shawn

4GSR

Re: Stainless mig welding
« Reply #3 on: November 21, 2023, 07:37:31 AM »
I recall they use 308 wire to MIG 300 series stainless with.  Speeds, feeds, voltage, play with until you get something that works. Follow the same as you do for steel and adjust accordingly.  High frequency not needed.  Practice on scrap until you get something that works.  Sorry I can't say much more than that.
Ken

Carpenter84

Re: Stainless mig welding
« Reply #4 on: November 21, 2023, 09:37:42 AM »
I recall they use 308 wire to MIG 300 series stainless with.  Speeds, feeds, voltage, play with until you get something that works. Follow the same as you do for steel and adjust accordingly.  High frequency not needed.  Practice on scrap until you get something that works.  Sorry I can't say much more than that.
Ok, that's fine.
But what I'm understanding is there isn't any major difference to mild steel? Figure out your settings, point and shoot? No special consumables (aside from gas and wire), or accessories?

4GSR

Re: Stainless mig welding
« Reply #5 on: November 21, 2023, 01:11:32 PM »
That's correct. nothing special other than the wire. No change in your gas either.  Now, if you want to whine a little, there may be a slightly different gas from your common 75/25 that may be recommended and available. :97:
Ken

Carpenter84

Re: Stainless mig welding
« Reply #6 on: November 21, 2023, 02:24:16 PM »
That's correct. nothing special other than the wire. No change in your gas either.  Now, if you want to whine a little, there may be a slightly different gas from your common 75/25 that may be recommended and available. :97:

Really! I read it has to have carbon dioxide.
Shawn

Carpenter84

Re: Stainless mig welding
« Reply #7 on: November 21, 2023, 02:25:29 PM »
I'll likely replace my tips and diffuser/nozel. Should I replace my liner too? For cleanliness?
Shawn

4GSR

Re: Stainless mig welding
« Reply #8 on: November 22, 2023, 03:26:44 PM »
"I'll likely replace my tips and diffuser/nozel. Should I replace my liner too? For cleanliness?"

I wouldn't worry about it unless it's needed. I'm no expert on the gas.  Try it with what you have first.  If it's not working, then change gas supply. Diffuser/nozzle/liner should not make a difference unless its bad to begin with.
Ken

Carpenter84

Re: Stainless mig welding
« Reply #9 on: November 22, 2023, 04:37:14 PM »
Diffuser/nozzle/liner should not make a difference unless its bad to begin with.

Yeahhhhhh...

Carpenter84

Re: Stainless mig welding
« Reply #10 on: November 22, 2023, 04:37:36 PM »
Thanks for the info, Ken. Appreciated.

PJB

Re: Stainless mig welding
« Reply #11 on: December 02, 2023, 10:37:13 AM »
No hands on experience here MIG-ing SS Shawn but I would think MIG will put a lot more heat in compared to TIG and in stainless that can be fun times. 


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Carpenter84

Re: Stainless mig welding
« Reply #12 on: December 02, 2023, 05:04:25 PM »
Yes, MIG puts out a lot more heat... However, so do I when I tig weld...  :a102: lol