Argon/CO2 mix & pure CO2

MIG Gas

MIG gas for mild steel is usually an argon/CO2 mix for a smooth arc and low spatter; pure CO2 is a cheaper alternative with more spatter. Adams Gas stocks both, rent-free, in hobby to trade sizes.

Why Adams Gas

Benefits & features

Full MIG/TIG/mix range

Pure argon for TIG and aluminium, argon/CO2 mix for MIG on steel, and pure CO2 as the budget option — all in stock.

Rent-free cylinders

No monthly hire and no contract, unlike the big-brand rental model. Pay for the gas plus a one-off refundable deposit only.

Fast cylinder exchange

Swap an empty for a full cylinder of the same gas and size in minutes — no waiting on a slow on-site refill.

Which gas for which job

Choosing your MIG gas

  • Argon/CO2 mix — the go-to for clean MIG welds on mild steel. Argon stabilises the arc, the CO2 adds penetration, and spatter stays low.
  • Pure CO2 — the budget option for mild steel. Deeper penetration but a harsher arc and noticeably more spatter to clean up.
  • Pure argon — for MIG on aluminium, where any CO2 in the mix would contaminate the weld.

Welding stainless or aluminium, or thinking about TIG instead? See our TIG gas guide or shop MIG welding gas →

How it works

What the shielding gas does

In MIG welding the gas flows from the torch to blanket the molten weld pool, keeping the oxygen and nitrogen in the surrounding air off the hot metal. Without that shield the weld turns porous and weak.

The gas you choose also shapes the arc: argon keeps it smooth and stable, while CO2 runs hotter for deeper penetration but a harsher, spattier arc. An argon/CO2 mix balances the two, which is why it is the workshop standard for mild steel.

Good to know

Frequently asked questions

Argon/CO2 or pure CO2 for MIG?

Argon/CO2 mix gives the cleaner weld with less spatter; pure CO2 is cheaper but spatters more and runs a harsher arc. Most workshops choose the mix for mild steel.

What gas for MIG on aluminium?

Pure argon. CO2 in the mix would contaminate an aluminium weld, so aluminium MIG runs on pure argon — the same gas used for TIG.

Can I exchange empty MIG cylinders?

Yes — bring back your empty Adams Gas cylinder and swap it for a full one of the same gas and size in minutes. Rent-free, with no hire contract.

Rent-free welding gas, ready when you are

Shop MIG, TIG and mixes online, or find your nearest stockist.

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