TIG welding (inert gas-tungsten electrode arc welding) an electric arc is ignited between a non-melting electrode (pure tungsten or its alloy) and the part to be welded in an inert gas (argon) protective environment. A scraping contact igniter is used to start the TIG arc. This process does not guarantee a high-quality weld at the beginning of the weld bead (compared to contact welding or an arc produced by a high-frequency generator).
TIG welding is used where an optimally finished appearance and minimal post-processing is required. This requires proper preparation and cleaning of the edges of the workpiece to be welded. The material of the fusible rod electrode must have similar mechanical properties to the material to be welded. Pure argon is always used as shielding gas. The amount of gas varies depending on the selected welding current.
The welders are certified and have the EN287-1,141,T,BW certificate and perform welding procedures in accordance with the European standard EN 288-3:1992+A1:1997, which has been introduced as the Estonian Standard EVS-EN 288-3:1998 and has been approved by the directive of the Standards Board 28.04.1998 No. 22.