Hand machined mechanical pencils

Arc lamp attachment for TIG welder (11/06/11)

This is a little attachment which slides over the end of a TIG torch nozzle and turns it into a rudimentary arc lamp. The entire assembly is connected to the ground lead. In the centre of the water-cooled brass holder there is an 8mm silver rod (silver, because of the high thermal conductivity and ease of cooling). The arc is formed between the tungsten tip in the torch and the end of the silver rod. Although it heats up quite a bit, it doesn't melt so long as there is water cooling present. Argon gas, and the emitted light, exit through the hole in the side of the stainless tube. A small tubular nozzle can be fitted to narrow the beam of light. To give some idea of scale, the main tubular body is ¾" diameter.

The most I can run it at is about 40A; any more, and the silver rod overheats. At this current, the power draw is approximately 600W (measured with a plug-top power meter in the welder's mains plug).

Silver rod in foreground

Collimating nozzle

Tip of tungsten just visible through the hole

Torch mounted. Note ground lead clamped to the tubular body.

Running without the collimator in place

With the collimator