310 Stainless Mig Welding

[Cryotech]

I have a trailblazer with a miller S-32p wire feeder hooked to it. I'am trying to weld 16ga. 310 stainless with .035 310 stainless solid wire with a 75% 25% mix for the gas. Can anyone help me with my settings the weld doesnt look the way its suppose to kind of black looks like its running hot but if turned down gets no penetration. Any help would be greatly appreciated. I'm in desperate need.
Thanks,
Chris Williamson

[aametalmaster]

Chris, I have the same problem with my MM185 on thin stainless sheetmetal. Turn it down and it dosen't stick. (this is where a tig is nice) I found my best with the heat up a little and run a downhill pass real quick. You can almost forget water tight. But i can get the parts to hold...Bob

[joebass]

I havent welded 310 before, but for 16ga I would probably TIG it. I have done 304 and used a .030 308Lsi wire and tri-mix gas. You might want to try the smaller wire and the tri-mix should definitley help with the blackness.

[Danny]

Using C-25 is automatically going to result in a gray / black soot covered weld bead. A little lacquer thinner and a SS brush should clean the weld up. They also make chemical cleaners that will remove the soot. If you want as soot free as possible welds, SS tri mix is the way to go.

[Blondie_486]

Hey Guys,

Try using a "Tri Mix" gas it's (I'm not sure so if I'm wrong on the percentages please correct me) 90% Argon 8% Helium and 2% Co2. I've used it before and it doesn't leave that black that you're getting the weld comes out looking a little bronze but will buff out if appearance is of any concequence. I know it works great on stainless exhaust systems and the shop I worked in before we used it on a job we MIG welded because that's what the customer specified. Personally I'd rather TIG or stick weld it but if the customer says they want it MIG welded and you want to keep them happy you MIG weld it for them.

Hope this helps
Blondie

[Revlimit]

Chris, you aren't alone in your frustration. I've seen some extremely talented welders thrown for a loop on thin SS sheet. I'll relay what I know about welding 310 SS. I would buy the Tri-mix. I'm unsure of your application, but the 25% CO2 you're using will negatively affect the corrosion resistance of your product due to carbon introduction in the pool. You may also try a smaller wire. Smaller wire provides you a more manageable arc at the lower Amp settings that thinner sheet needs. Another thing, if you have inductance adjustment, a higher output inductance setting gives you a "wetter" puddle and the bead will lay down a little more . Make sure that you have a good ground as well. Just laying your workpiece on a grounded table can give you an erratic and unpredictable arc. That's all I can think of for now. Good luck. Rev.

[HAWK]

Hey Guys,

Try using a "Tri Mix" gas it's (I'm not sure so if I'm wrong on the percentages please correct me) 90% Argon 8% Helium and 2% Co2. I've used it before and it doesn't leave that black that you're getting the weld comes out looking a little bronze but will buff out if appearance is of any concequence. I know it works great on stainless exhaust systems and the shop I worked in before we used it on a job we MIG welded because that's what the customer specified. Personally I'd rather TIG or stick weld it but if the customer says they want it MIG welded and you want to keep them happy you MIG weld it for them.

Hope this helps
Blondie

Blondie,

On the money! The mix may vary from area to area. I use a 90% Ar, 7.5% He, and 2.5% CO2. It is the best thing for ss short arc I have found. For a spray arc the 98% Ar with 2% O2 is the ticket. It is also less money than the tri-mix.

[Revlimit]

HAWK....I used to know what the 2% O2 was in the mix for, but I've forgotten. Could you tell me a little bit about the 98/2?

[HAWK]

Revlimit,

The oxygen does 2 things: It prevents undercut exhibited by pure argon shield in the GMAW process and it also preheats the wire. This helps achieve the spray at a lower voltage/wire speed. It is not much good for short arc unless you are running a high inductance machine to help wet out the "ropey" puddle.

Hope that helps.

[Revlimit]

Thank you.Rev.

[VBI]

Chris, I wire feed mostly 10 gauge 304L and 316L ss sheet. I use short circuit and Tri-Mix with the respective .035" 308Lsi or 316Lsi wire. I set the gas reg. at just under 20 cfh and adjust the wire speed up a little fast and push the weld at 15 to 30 deg. weld angle.

I welded 16 ga. 316L a while ago with .023" 316Lsi wire and Tri-Mix, but I can't remember the machine settings. I do remember I was able to position the work so I could run a fast vertical down bead with good results.

I would think you would need to go to a smaller wire and a Tri-Mix as suggested by others so as to use short circuit transfer.

[Paul Seaman]

VBI:
I agree, my thought was the wire size seemes too large for thin material, I've welded 16ga with .030 but not any heavier wire than that.

Good luck Cryotech,

[Cryotech]

Thanks Everyone,
I appreciate all the help. Good to know that its not just me that is having these problems. I'm gonna go to the trimix and smaller wire and see what that does. We have been tigging them but it takes so long to do one part and the customer is wanting to try mig to speed up production of them. More more more you all know how that is thanks again for all the help.
Sincerely,
Chris Williamson

[John G. Acosta]

I have a trailblazer with a miller S-32p wire feeder hooked to it. I'am trying to weld 16ga. 310 stainless with .035 310 stainless solid wire with a 75% 25% mix for the gas. Can anyone help me with my settings the weld doesnt look the way its suppose to kind of black looks like its running hot but if turned down gets no penetration. Any help would be greatly appreciated. I'm in desperate need.
Thanks,
Chris Williamson

Chris,
First I would use .030" ER310 wir and 90%He/7.5%Ar/2.5%Co2 shielding gas.
Make sure you are running in a good short arc mode of transfer. Using the .035" wire requires a higher current density than .030". You will notice a difference between the diameters, especially welding 16gage S.S using short arc. Short arc is a low current & voltage process. Transfer of the arc in stainless short arc requires a good setting. Also weld downhill as much as you can position the work. You will have less chance of blowing through. S.S. thermal properties requires good welding technique to keep distortion at a minimum.
Good Luck,
John