Preparing Tungsten - Weldclass Weldforce 202T Operating Instructions Manual

12.1.2 Preparing Tungsten

The electrode should be pointed (tapered) according to the welding current.
Grind end of tungsten on fine grit, hard abrasive wheel before welding. Do not use wheel for other jobs
or tungsten can become contaminated causing lower weld quality.
Rule of thumb is that the taper section should be 2.5 times the Electrode Diameter.
Figure 44
Ideal Tungsten Preparation = Stable ARC
Diameter of the flat left on the end of the Electrode determines amperage capacity.
Figure 45
Wrong Tungsten Preparation = Wandering ARC
Figure 46
Pointing the Tungsten Electrode
The electrode should be pointed according to the welding current.
Figure 47
Note that when welding in AC Mode the tungsten should automatically form a 'ball' shape on the end.
This is perfectly normal and this is what is required for AC TIG welding.
Electrode Angles
Angle @ Range of Current (Amps)
30° 0 – 30
60-90° 30 -120
90-120° 120 - 250
120° ≥250
Table 12