A few weeks ago I was watching a welding video where the guy actually talked about hooking up his welder to a tank of oxygen to use as a shielding gas. The comments, as you may expect, exploded. He thankfully didn't, as he'd only mispoken. He wasn't MIG welding with oxygen. He meant to talk about CO2, the gas that welders use as a shielding gas for MIG welding. Sometimes welders mix CO2 with argon, and that's what we're going to discuss today.
At Welding Tips and Tricks, Jody put together a MIG welding video that compares how CO2 and argon stack up. Though CO2 is sometimes avoided because it may cause more spatter, it is usually cheaper than a CO2/Argon 25/75 mixture. Check out this video for more than a lesson in shielding gases. You'll also learn a lot about MIG welding in the process.
Jody's test concluded that both gases performed quite well and that the test didn't show a clear winner. He wrote, "if the voltage and wire speed are balanced to find the sweet spot, CO2 gas can actually run very smoothly with little or no spatter. Especially when using inverter power sources that have an inductance setting favorable to Co2 shielding gas."
Throughout the video the one thing that stood out is that a welder's technique, metal prep, and welder settings can make a significant difference. For finer work on thin metal a CO2/Argon mixture may produce a cleaner weld, but if appearance isn't as significant a factor, then CO2 works just fine for experienced welders who know how to position their torch, run the wire at the optimal speed, and travel fast enough to penetrate the metal without creating a crown on the weld.
Besides teaching good welding techniques, this video also teaches welders how to cut apart their test welds and to examine them to ensure they're prenetrating the metal properly. Learning how to diagnose problems in your weld with these tests make this video especially valuable for beginning welders who may need to work on their technique.
