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Basic Technique of TIG Welding

TIG stands for Tungsten Inert Gas Welding and is also known as Gas Tungsten Arc Welding (GTAW). It is a commonly used high quality welding process. TIG welding has become a popular choice of welding processes where high quality and precision welding can be achieved.

In TIG welding an arc is formed between a non-consumable tungsten electrode and the metal being welded. Gas is fed through the torch to shield the electrode and molten weld pool. Sometimes a filler wire is used and added to the weld pool separately.

basic-technique-of-TIG-welding

 

Advantages of TIG welding:

  • Superior quality welds
  • Welds can be made with or without filler metal
  • Precise control of welding variables (heat)
  • Free of spatter
  • Low distortion

 

Disadvantages of TIG welding:

  • Undercutting
  • Tungsten inclusions
  • Porosity
  • Weld metal cracks
  • Heat affected zone cracks

 

TIG welding process

In TIG welding, the key thing to take note is how the filler rod is fed and kept in the shielded gas area to avoid contaminating the filler wire. Most of the other factors have to do with how the arc is started. As a rule of thumb, the torch is generally held at about 20 degrees from vertical, tilted so the tungsten points in the direction of the weld. The purpose of the tilt is to enable the weld pool to form ahead of the torch, so as to permit easy access for filler rod. The gap between the tungsten and the work should be maintained at between 1 and 1.5 times the tungsten diameter.

 

Things to take note in TIG welding

  • Erratic arc
  • Excessive electrode consumption
  • Oxidized weld deposit
  • Arc wandering
  • Porosity
  • Difficult arc starting