Interesting that you mention this. I've been looking at stuff like
this myself lately.
This is called Resistance Welding or Spot Welding. Jewelers call it
a fusion welder.
I've seen one in the Frei and Borrel catalog.
I wouldn't recomend you trying to construct it without some
experience with electronics, especially high voltage electronics.
The power involved can very easily kill you if you shock yourself
with one. Definately enough to give you severe burns and/or stop
your heart. Anything that has enough juice to melt metal is best
treated with lots of respect.
Basicly, we are talking about a power source that turns 220 v and
converts the current down to 4v and a crapload of amps, on the order
of several hundered, using a either a transformer, a capacitor, or
A useful URL is: http://www.frii.com/~katana/spotweld.html
Ken "Wirehead" Wronkiewicz \ \ \/
http://www.wirewd.com/wh/ \ \