The type of gas used can significantly affect the weld’s quality. TIG and MIG welding each require their own different gas to produce the best possible welds.

TIG welding requires pure argon gas, which will provide a clean weld with no oxidization.

MIG welding requires an argon, CO2 and/or oxygen mixture for more penetration and heat.

Pure argon gas is needed when TIG welding because, as a noble gas, it doesn’t react to other elements during the welding process. That way, you’re left with a clean weld free of oxidisation and other defects.

A gas mixture is needed when MIG welding because the addition of CO2 and/or oxygen provides the necessary heat and penetration required for a successful weld. The only time you would need pure argon when MIG welding is if you’re working with aluminium.

Comparing the Effects of Different Gases on Weld Quality

As demonstrated in our quick, thirty-second video, you can see the visual differences when using the wrong and right welding gas.

Pure argon in TIG welding: With pure argon in TIG welding, a nice, clean, unoxidised finish is achieved.

Argon mixture in TIG welding: Conversely, using an argon mixture intended for MIG welding while TIG welding can lead to subpar results, including defects within the weld that compromise its integrity.

Argon mixture in MIG welding: Using a gas mixture while MIG welding results in a hot, penetrating weld.

Pure argon in MIG welding: If pure argon is used in MIG welding, the result is a cold, non-penetrating weld. This highlights how pure argon is not suitable for MIG welding due to its inability to provide the necessary heat and penetration.

For the best results, make sure you’re using the right gas.