MIG Welding Gas Review

The test

All welds were made in the same hour with the same welder settings on 1.5mm steel using a curving ziz-zag motion. The gases were sourced from a DIY store and were all used at the same regulator setting, apart from the Argoshield Light which was in a big bottle with a different regulator.

CO2 vs Argon/CO2 Mix

The weld to the right was made using 80% Argon, 20% CO2 shielding gas. It was nice and easy to do. The arc was very stable and controllable and the weld turned out quite neat.

100% CO2 gas was used for the weld on the left. The arc felt much less stable with CO2 shielding gas, and the weld progressed in a stuttering fashion with blobs of molten weld (spatter) being blown off at regular intervals. That's a bit of spatter stuck to the weld about half way up on the left. The arc also seemed slightly brighter than with the argon mix.

For much more detail - Shenion from the forum has a page comparing various percentage mixes of CO2 and Argon.

Argon/CO2 Mix vs BOC Argoshield Light

There wasn't much to choose between the Argon/CO2 mix from Halfords and Argoshield Light from BOC. That's not too surprising as their composition is similar. Argoshield Light is approximately 93% Argon, 5% CO2 and 2% oxygen.

The oxygen in Argoshield is supposed to improve wetting and make the weld smoother, and indeed the weld made using Argoshield is very slightly smoother than the other weld.

Pure Argon Gas

Pure Argon is intended for aluminium welding rather than for steel, but I had a bottle so it's included for completeness.

The arc was slightly less even than the Argon/CO2 mixes, but still very good. The weld build up was much higher than with any of the other shielding gasses (bad), and there was an odd roughness around the edge of the weld - possibly due to stray arcing. The difference was enough for me to trade in a half full bottle of Argon for a new bottle of Argoshield now that my aluminium welding is finished.