- To create a TIG weld, the welder holds the electrode at a 10 degree angle from vertical, with the electrode pointed in the direction of the weld. This is called the "push" method, and the process "pushes" the metal along the weld. This position also maintains optimal coverage of the shielding gas, resulting in a clean, consistent weld. The welder must maintain a short distance between the electrode and the work piece while preventing physical contact. TIG welding is considered more difficult than MIG welding or gas welding processes. The welder moves the electrode around in a small circle until a pool of metal is formed, and then he begins a cyclic process of moving the electrode forward and adding filler material as needed. The process continues until the end of the weld is reached, and the welder pulls the electrode away from the work piece, allowing it to cool.
- The hot wire technique includes pre-heating the filler wire to increase the rate of melt of the filler material, resulting in more material being deposited into the weld. The energy from the arc is used solely to heat the work piece, rather than requiring a diversion of some of the energy to melt the filler wire. This method is used for thick welds where a significant amount of filler material is added.
- Pulsed current TIG welding is used on thin pieces such as sheet metal where excess heat can cause burn through or warping. The power supply cycles through two levels of voltage. The higher level of voltage causes the material to melt, and is then allowed to cool during the period of lower voltage. This process can be automatically programmed for specific weld rates to maintain lower heat levels in the work piece.
