What must be done to the tungsten electrode before starting the GTAW process?

Before starting the Gas Tungsten Arc Welding (GTAW) process, it is essential to ensure that the tungsten electrode is cleaned and grounded. Cleaning the tungsten electrode is crucial because contaminants such as oils, dirt, or oxidation can impact the stability of the arc and the quality of the weld. A clean electrode allows for a more precise arc, leading to better heat control and fusion of the materials being welded.

Grounding the tungsten electrode is equally important, as it creates a complete electrical circuit necessary for the welding process. Without proper grounding, the electrode may not produce a consistent arc, which could lead to welding defects or difficulties in achieving the desired weld quality.

Coating the tungsten electrode is not a standard practice in GTAW. Tungsten is typically used in its pure form or alloyed with small amounts of other materials (like thorium or zirconium) to improve performance, but it should not be coated. Heating the electrode before use is unnecessary and could degrade its performance. Bending the electrode is generally not recommended as it can lead to mechanical failure or improper arc generation.