What is the method to start the TIG arc?

• A. Manual crude start
• B. Low frequency start
• C. High frequency (HF) start or lift start
• D. Scratch start

Answer: (C)

Starting the TIG arc cleanly means initiating the arc without touching the tungsten to the workpiece and without introducing contamination. The best way to do this is using a high-frequency start, which uses a high-frequency signal to ionize the shielding gas and jump-start the arc as soon as the electrode is near the metal. This lets you start the arc quickly and with a stable, clean ignition, avoiding tungsten contamination and tip erosion.

If high-frequency start isn’t available, a lift start is a good alternative: you briefly touch the electrode to the workpiece to establish contact, then lift the electrode away while maintaining current to ignite the arc. This approach also minimizes contamination compared to methods that involve dragging or scratching the electrode across the surface.

Methods that involve crude touching or scratching the workpiece to start the arc can contaminate the tungsten and the weld area, lead to irregular arc ignition, and worsen weld quality.