What can occur if filler metal is exposed to air for too long during GTAW?

When filler metal is exposed to air for an extended period during Gas Tungsten Arc Welding (GTAW), it can become oxidized. This oxidation occurs because the surface of the filler metal reacts with oxygen in the air, forming oxides. The presence of these oxides on the surface can contaminate the weld by introducing impurities, which compromise the integrity and quality of the weld. The oxidation can lead to issues such as poor fusion, reduced ductility, and the potential for cracking in the weld joint.

In the context of GTAW, maintaining a clean and uncontaminated filler metal is crucial for achieving strong and sound welds. That is why it is essential to store and handle filler metals appropriately, minimizing their exposure to air, to ensure optimal performance during the welding process.