Co2 argon mix ratios

[minimutly]

I took my argon/co2 bottle to the motor factors for changing this morning (Adams gas supplier I think). I'm nearly sure the old one was 5%. The new one is 12%. Am I likely to see a huge difference?
Have to say I've welded with CO2 quite happily in the past, recently used neat argon for a small job when the mix ran out...

 

[Erie Fred]

IIRC the change over happens around 80% Argon.
Under that you'll not get into spray mode.
If your doing thin metal, your in short arc anyways, so not such a big difference.
Some one else can add some more information, as I'm not doing sheet metal
with a mix (100% CO2 here)

 

[My Old Landy]

I run 80/20 as it was purchased by mistake. It works ok for me.

 

[Munkul]

You'll want either a bit higher voltage or a bit lower wirespeed with the heavier CO2 mix, and it will give slightly more penetration. Other than that, you won't notice it too much.

 

[minimutly]

Interesting how you phrase that - heavier Co2 mix. To my mind 5% to 12% is an increase in argon? I would term that a lighter Co2 mix. Or have I got this wrong?

 

[AVI_8]

Interesting how you phrase that - heavier Co2 mix. To my mind 5% to 12% is an increase in argon? I would term that a lighter Co2 mix. Or have I got this wrong?

It’s the other way around, 5% Co2 to 12%
Im using hobby weld 5 which is 93% Argon 5% Co2 and 2% Oxygen

 

[steve t]

You won't notice much difference really

 

[Munkul]

We found that on the Miller XMT we ran approx 3-4 volts higher for the same wirespeed, going from sureshield 5 (5% CO2, 2% O2) to Sureshield 15 (15% CO2, 2% O2)

ie a nice short arc setting at 18v on 5% needed 21-22 volts at 15%.

It created loads of spatter otherwise due to a buried arc. More volts lengthens the arc again and cleans up the transfer. And we always start the volts low and increase until minimal spatter is created, as the easiest way to find the optimal setting.

I was surprised at how many extra volts were needed, but this would be masked on a transformer MIG as you just turn the tap one higher and tweak the wirespeed a little.