What is the correct procedure to start the TIG arc?

• A. Scratch like stick welding
• B. Use HF start or lift start, don't scratch like stick welding
• C. Strike the arc by tapping the tungsten on the work
• D. Increase current slowly after contact

Answer: (B)

Starting the TIG arc cleanly means initiating the arc without dragging the electrode across the work or contaminating the tungsten, all while keeping shielding gas flowing. The best way to do this is with either a high-frequency start or a lift start. A high-frequency start uses a built‑in oscillator to ionize the gas and strike the arc instantly, so there’s no contact between tungsten and work and the weld remains well shielded. A lift start involves briefly touching the tungsten to the work to establish a path and then lifting the tungsten away to form the arc; this also avoids contamination and keeps the shielding gas on.

Scratch starting, like in stick welding, would drag the tungsten across the surface, which can contaminate the tungsten tip and the weld with oxides or tungsten inclusions, disrupt the shielding gas, and lead to an unstable arc. That’s why the preferred approach is to start with high-frequency or lift start rather than scratching. Once the arc is established, set the current to the weld condition you need.