Which method is commonly used to create a weld pool in TIG welding?

In TIG welding, a weld pool is created by the arc generated between the non-consumable tungsten electrode and the base metal. This arc produces intense heat, which melts the base metal to form the weld pool. The ability of the arc to be precisely controlled in TIG welding allows for this method to produce high-quality welds with minimal contamination and distortion, making it highly effective for working with various metals and thicknesses.

The other methods mentioned do not directly establish the welding arc necessary for creating the weld pool. While direct contact may seem relevant, it actually does not apply since the tungsten electrode does not touch the base metal. Instead, it maintains a short distance to facilitate the arc. Gas pressure, on the other hand, pertains more to shielding gas protection rather than weld pool creation. Lastly, electrode extension refers to the distance the tungsten electrode extends from the torch, which affects the arc characteristics but does not directly create the weld pool. Understanding this foundational aspect of TIG welding is essential for achieving effective and precise welds.