Short answer, you're machine's capacity for amperage/voltage isn't high enough to produce the spray transfer that is required of that wire/gas combination. That's it in a nutshell. Best regards, Allan

 

Thanks Allan+Dan, I was thinking that could be it too. Although, I was welding 26 ga (0.018") stainless sheet. It really should have enough juice to weld that thin of a sheet (or not?).

I also saw this thread where a guy used a 110v to weld stainless sheet, he was having problems and realized it was the wire. After getting different brand wire it worked fine:

http://www.thesmokering.com/forum/v...?t=55593&postdays=0&postorder=asc&start=20&sid=a4b7e39731f5fb0536699af0efcbfb17

 

Due to the helium in the mix, Tri-mix requires more voltage then 75/25. The metal transfer with the helium tri-mix is still going to be short circuit transfer.

 

Looks like you are right. In the link i just posted the guy wasnt using trimix. I also just tried the stainless wire with 75-25 and it worked fine, minus the black soot. I'll be going back to airgas tomorrow and swapping out for another mix.

Would 98% Ar - 2% CO2 work with my 110v mig for stainless? I heard this mix also works well for stainless. Assuming that since it has no helium, my 110v can handle it?

 

I've never tried 98/2CO2 with stainless to know how well it performs. I suspect you should have the voltage available to run .024 solid wire with it. Puddle wet out may be on the sluggish side. A high silicon stainless wire would help improve puddle wet out.

 

I'm by no means an expert, but with aluminum TIG welding, the He gives you extra heat, not less, so I would have thought it would play nice with the tri-mix.
I wonder if the lower percentage of CO2 is causing the trouble, since high Argon levels run cooler and require more amperage, from what I've understood. If that is the case in your situation, the 98%/2% probably will still behave poorly.

This is just my $0.02 though, and definitely to be taken with a grain or ten of salt!

 

The helium addition in the gas mix does help increase heat input and weld puddle fluidity. However, as I pointed out the addition of helium requires more voltage. The little 120 unit, this thread is based on, may not be able to out put the necessary voltage. I haven't ran the unit to know it limitations.

With Stainless steel you want to keep the CO2 content in the gas mix low. To high of a CO2 content can lead to corrosion issues or cracking

 

You are only pushing 70 amps...I am not sure about the voltage. But I'm guessing since Campbell says the welder can do stainless...That maybe it can with the correct mix. So maybe its that you have the wrong Tri-mix

Campbell Hausfeld WG2160 MIG/Flux Core Wire Welder
Product Description
115 Volt, 70 Amp DC output, 20 Amp input and built-in gas liner and valve. Welder is MIG ready and requires no additional parts. Start your project in minutes! WG2160 has four heat settings to match your metal thickness.
The WF2150 says it does stainless....
Capable of welding mild and stainless steel from 18-ga. to 3/16"; 4 heat settings for varying metal thicknesses


FWIW...On my Tweco 141i....which is a 120volt -140 amp unit also...they recommend a tri-mix of 90% argon 7.5% Co2, and 2.5% O2 set at 17 volts


I found this on the Hobart website discussing this mix.

The trimix gas that Mustang referred to is an Argon/CO2/Oxygen blend. The oxygen content being around 2%. This gas is commonly sold where a customer may want to achieve a spray transfer. With 75/25 best you can get is a globular transfer. With the Ar/CO2/O2 blend you can short arc as well as spray arc.

http://www.hobartwelders.com/weldtalk/archive/index.php/t-5066.html

Maybe if you switch to this mix without the helium....you'll get better results. I have not tried my welder with any stainless yet....So thats all I can offer.
If you switch gasses to the above mix of Ar/Co2/O2 and it works better...Let me know please because I would be curious as to the affect of that mix and your results. Good luck.

 

Like Dan said you cannot get enough voltage for helium tri-mix out of a 120V welder. You can use 98% Ar/2% CO2 but you will find it difficult to weld out-of-
position.

The gas that TIM9 refers to, 90% argon 7.5% Co2, and 2.5% O2, is too oxidizing for good results on stainless, not much better than 75/25.

If you are limited to 120V power, you will have to compromise somewhere.

John

 

Yeah been there done that, it's frustrating to say the least. If you really want to weld stainless but don't have the budget get a stick welder. HF has their 80 amp inverter on sale right now for like 150$. It will run 3/32 308l rods surprisingly well at 55-65 amps. Which is right around 30% duty cycle, not too shabby for cheap. Be sure to get the extended warranty you'll need it lol. Good luck!

 

Are you all saying stainless has to be spray transfer? It seems like normal steel, short circuit transfer, even with tri-mix.

 

stainless steel with the helium tri-mix will be short arc or globular transfer. 98/2 oxy is a common gas mix for spray arc on stainless.

 

You need about 100 amps to weld 14 gauge, your machine only puts out 70, that puts in the range of 18 gauge SS.