About twenty years ago I had an opportunity to use a "plasma cutter"
that consisted of two carbon rods held near each other by a sort of
mechanism that was operated by a pair of handles like pliers. Give the
handles a squeeze and the rods came together to start an arc. Another
motion turned on the air and a stream of air blowing through the arc (200 +
amps, IIRC) would cut just about anything you set your mind to, metal or
not. Not necessarily cleanly, but for demo work the cutter didn't care what
was in front of it.
Has anyone ever seen or used this device? Has a modern plasma cutter
replaced this widget? If this is still around, then perhaps all one needs
is a good power supply to do what a plasma cutter does now.
The difference is immense. Get some hands-on with a real modern plasma
cutter and you'll be convinced. The cut quality is vastly better, and
the cut capacity for a given current is also much improved.
I used to use a single carbon rod with air or an "Air Arc" that would really
work well for gouging out welds. My plasma cutter works well for gouging
smaller welds but can't hold a candle to the amount of metal it can turn
into a molten stream compared to the Air Arc. I really liked the way you
could see the crack under the bead. As far as severing a peice of steel the
OA torch worked better but for thinner iron not as well as the plasma
cutters do now. I have my plasma cutter on a CNC table and very seldom run
it by hand.
Some of the things I make, posted on eBay