TIG Welding Company

Some older welders still refer to TIG as "heliarc," which is what the process originally was called.

Heliarc was perfected around 1941 and was used to weld on magnesium, aluminum, and stainless. It was especially helpful in the war effort for welding on airplanes.

Heliarc used pure helium as an inert (meaning it won't combine with other elements) shielding gas to protect the weld pool from the atmosphere. (Nitrogen, hydrogen, oxygen, carbon dioxide, and other elements cause weld defects if introduced to the weld pool.)

Enter Argon

After a while it was discovered that argon has some advantages over helium. Because argon is heavier than helium, less flow rate is needed. (We use about 20 to 25 cubic feet per hour (CFH) in our shop.) The lower flow rate requirement makes argon better for flat welding. Helium is good for overhead, because it is lighter and thus flows upward.

Argon allows easier arc starting and a smoother, more stable arc than helium does. Actually, argon pretty much is the most widely used shielding gas nowadays.

Since the heliarc process no longer used only helium, someone decided to rename it TIG for tungsten inert gas welding.

Later the same guy who changed the "library" to the "learning resource center" must have decided TIG was too easy, so he named it gas tungsten arc welding (GTAW). But most everyone I know in the shop and field still call the process TIG.

Non-consumable Electrode

TIG uses a tungsten electrode that is non-consumable. In other words it does not burn up like an electrode in stick welding or the wire in metal inert gas (MIG) welding does. The tungsten acts as the torch - it generates heat, which melts the metal and/or filler metal. Thin metals can be joined by TIG welding without using filler metal. Joining thicker metals requires using an approximately 3-ft.-long filler rod of various diameters that is fed into the weld pool with one hand, while the torch is manipulated with the other.