GMAW shielding gas question

Date 06-16-2022 10:58

Would like to choose one of these gases for my use. Can you tell me which you would select and why you would choose it over some of the others?

Parameters:
All mild steel, A36.
1/4" up to 1" thicknesses.
Flat, horizontal and vertical down positions.
Fillets, laps and butt joints.
.045 70S-6 wire.
Voltage, whatever I need.

If you have another gas that you prefer please list it and let me know why you prefer it.
Thank you as always.....

Gases:
98%AR / 2%O
95%AR / 5%O
95%AR / 5%CO2

By jwright650 (*****)

Date 06-16-2022 12:10

I know of a fab shop that uses a 85/15 mix and loves it. It still allows for spray transfer on mild steel, like all of the mixes that you mentioned, but it is a bit cheaper due to less argon in the mix.

By louis2

Date 06-16-2022 12:25

Thank you
Is the 15% O or CO2 ?

By jwright650 (*****)

Date 06-16-2022 13:17

C15, 15% CO² the balance in Argon

By 803056

Date 06-27-2022 16:22

First off, I wouldn't use GMAW-S on material greater than 3/16 to 1/4-inch. If you need to weld in all position, consider getting your hands on a machine with pulsing capabilities. That being the case, something with better than 80-90% argon is worth looking into. No more than 12% carbon dioxide. More argon, less spatter, so how much clean-up can you tolerate?

Al