Gas differences

[Single-phase]

Hello all, I have enjoyed reading many great posts on this forum, and have a question for you.

I have a mig welder - occasional / hobby use - it is an older Uni-Mig 235 (max 250 amps).
Mild steel use (0.6 wire and 0.9 wire) and used Argoshield light in the past.
Welding the lighter stuff up to 6mm. Dip-Transfer

I am looking to hire a cylinder of shielding gas (E size) which - if I don't forget to turn off the tap - will last me a long time.

Comparing the different suppliers and mixes that might suit gives me several to choose from.
BOC have
Argoshield Light= 3% Oxygen, 5% CO2, 92% Argon
Argoshield 40= 5% Oxygen, 95% Argon

Supagas has
Supa Argon 52= 2% Oxygen, 5% CO2, 93% Argon
Supa Argon 07= 7% Oxygen, 93% Argon

If I remember rightly, CO2 gives a bit more "bite" so better penetration.
What differences would I expect to see between Argoshield 40 and SupaArgon 07?
Is this a case of suppliers being different in their mixes just for the sake of it?

Are the Tri-mixes generally more expensive?
I have not price-shopped as yet.

[Grahame Collins]

If Argoshield light worked for you in the past, I would stick with what you know.
If thats not viable at least something close to it.in gas% ratios.

Grahame

[Single-phase]

thanks - something I did not consider was my adjusting to a different gas. I am not yet consistent enough to pick the gas changes over my own variations, but was keen to understand the reason behind very slight mix differences. At least if I stick with argoshield light, and my shed power point, my setting notes should be valid.

[Grahame Collins]

The other mixtures are used in industry to gain a specific outcome and often used in a set procedure with a particular wire.

With what we are doing for home welding operations you will find that the argoshield light or its equivalent will be just fine.

Grahame