Daily Handy Tips

The “TIG” in TIG welding stands for Tungsten Inert Gas. But before it was named so, it was called “Heliarc” because of the helium that was dominantly used when the process was invented. But then someone discovered that argon worked better and so it was called “TIG” because inert gas could refer to either helium or argon.

Soon later, it was discovered that small additions of hydrogen worked well for some metals. The word “inert” no longer applied to the new discovery. Thus, the technical term for what used to be called TIG and Heliarc is now “GTAW” or Gas Tungsten Arc Welding.

TIG welding, however, is difficult to use compare to the other arc welding processes. It is required to use both hands where the torch is held in one hand and the filter rod in the other. Often times, a foot pedal amperage control is used which makes it more difficult.

The TIG torch can either be water or air cooled. It is designed also to give shielding gas and welding current through a tungsten electrode. A ceramic nozzle leads the shielding gas to the weld puddle and internal copper parts like the collet and the body holds the electrode in place. The tungsten electrode is sharpened for applications where the arc need to be pinpointed and for very low amperage.

The arc that is made between the tungsten electrode and workpiece creates the heat that melts the metal and makes the weld puddle. The arc is shielded by argon, or helium or the mixture of both. Sometimes for certain alloys, hydrogen is added in small percentage to improve the flow of puddle. The arc is very smooth, quiet and clean when DC current is used. However, when the TIG welding machine is set on Alternating current, it is slightly noisier but still clean and smooth.

Here is a list of some popular metals that can be welded using the TIG welding process: Carbon and low alloy steels like 1010 carbon and 4130 chromoly steels; 301, 321 and 17-7ph stainless steels; inconel 718 Nickel alloy and X Hastelloy; Aluminim alloy like 6061 and 5052; az31b Magnesium alloys; 6a14v Titanium alloys and those that are commercially pure; Stellite 6b and 1605 Cobalt alloys; copper alloys like Nibral bronze and pure copper and a whole lot more.