Thoriated tungsten electrodes belong to tungsten electrodes, so they should be prepared according to tungsten electrodes preparation.
The tungsten electrode is the crucial carrier in the welding process and must be ground and cut properly. An improperly prepared electrode leads to arc wander, splitting, shedding, inconsistencies, or expensive mistakes. Properly ground and cut electrodes improve arc starting and stability.
Tip (Flat) preparation. Depending on the welding process, flat preparation might be on a new electrode or a previously used electrode. If the end of a used electrode is very contaminated, it should be removed before flat preparation. To recondition an electrode that has minimal contamination, either new or cut off, place the electrode at an exact 90-degree angle to the side of the wheel.
Taper Grinding. The most important element of proper electrode grinding is that the electrode be ground longitudinally. Tungsten electrodes are manufactured with the molecular structure of the grain running lengthwise, so grinding crosswise is grinding against the grain. So do thoriated tungsten electrodes.
Cutting to Length. A contaminated electrode produces an erratic arc and a contaminated weld. The best way to ensure that all contamination is removed from the tip is to cut off that part of tungsten. Grinding the tip when it's contaminated may not remove all of the contamination and will deposit the contamination on the grinding wheel, only to be picked up again in future grinding.
Electrode angle Surface Finish. The smoothness of the finish on the prepared tip of the electrode determines some of the characteristics of the welding process. In general, points should be ground as fine as possible to improve welding properties and increase the service life of the electrode. Electrodes that are ground too coarse result in unstable arcs.
There are lots of points that should be concentrated during preparation. Do as instructions in order to keep longer lifespan of tungsten electrodes.