Which method should you use to start the TIG arc?

• A. Scratch like stick welding
• B. Increase current instantly
• C. Use HF start or lift start, don't scratch like stick welding
• D. Tap the tungsten on the base metal

Answer: (C)

Starting the TIG arc cleanly means initiating the arc without contaminating the tungsten or the workpiece and with a stable, controlled ignition. Using high-frequency start or lift start achieves this by guiding the arc into existence without dragging the tungsten across the metal.

High-frequency start uses an RF signal to ionize a path so the arc can form instantly when you bring the electrode close, without touching the base metal. Lift start accomplishes a similar effect by lightly touching the tungsten to the metal and then lifting away to strike the arc, which avoids contaminating the tungsten tip. Both methods keep the tungsten clean and reduce the chance of inclusions or oxidation entering the weld, leading to a smoother start and better overall weld quality.

Scratch starting, like in stick welding, involves dragging the tungsten along the surface to create an arc. This can contaminate the tip and the work, leading to tungsten inclusions, a rough start, and unstable ignition. Jumping the current too high at the instant of start can also cause an unstable arc, spatter, and crater formation.

So the recommended approach is to use high-frequency start or lift start, as they provide a clean, controlled arc initiation without the drawbacks of scratch starting. If your machine lacks high-frequency capability, lift start is the best practical alternative.