This would almost be worth it's own setup. I have the stick welder, now
how much would I need for an argon regulator and bottle plus some spare
How much carbon contamination could one expect, I wonder?
I am not sure I fully understand your question. For myself, since I
have argon. electrodes and whatnot, I can always make a separate
electric melting setup using tungsten electrodes and argon, and my welder.
Yep. I figure, I have plenty of stuff to experiment with. Flowerpots,
100% duty cycle 200 A welder, argon, tungsten electrodes, wires etc.
I have other mechanical things on my todo list, on top of which is
making a DC -> AC inverter for the welder. But maybe in winter I may
have a tiny bit of time.
I would have thought that would work fine providing you can put in
sufficient heat to melt the volume contained in the crucible. At higher
temps you would probably wants to insulate the crucible to reduce the
heat loss and power consumed. I may try this for melting pewter
(britannia metal), it TIG welds beautifully but when casting and heating
with propane some dross in produced. Even trying an argon shield might
be worth my while trying.
It sounds like it could work. One possible problem I can foresee is this:
The arc will generate heat at the top of the metal, and melting down into
the crucible will be sort of equivalent to "penetration." There is a
likelihood that before you get all the metal heated up and melted, you will
overheat the electrode and damage it.
Just curious and throwing gas on the fire here....due to the localized
heating aspect of the Tig arc, would there be a problem with uneven
thermal expansion of the crucible that could lead to cracking? A
standard oven/furnace heats the crucible fairly uniformly but a tig melt
would have far from uniform heat distribution.
Koz (who is interested in giving it a try...great idea for small melts)
I think you may be slightly confused. A stick welder has no facilities
for putting the argon in the same place as the electrode. The best you
could do would be to spray out the argon somewhere near the electrode.
Does anyone know if argon is a heavier than air gas? I'm guessing it
is, but it may not be much heavier, and thus difficult to completely
cover a crucible.
Absolutely. Later in the thread you say you have 100% duty cycle, and later
still you mention 200 amperes. At a typical arc voltage of say 30V, that's
a good 6kW burning away the argon. (Which BTW is slightly heavier than air;
argon heated to 5000°F however isn't! ;-)
Figure 1kW per pound of steel in a reasonable furnace. You'll need a layer
of high-temp kaowool or fiberfrax or whatever to insulate it good, then a
hard refractory hearth to melt the steel in; a small crucible wouldn't hurt,
but mind if it comes with a protective glaze that'll eat the hell out of the
kaowool! The arc obviously has to be enclosed to save heat (your greatest
loss at lightbulb temperatures here is radiation, and there's about 6kW of
it...), so you'll need another hardened hemisphere enclosing the deal with
no gaps for light (heat) to get through.
Two carbon gouging rods will certainly work well here (at 200A, you'll
probably want 3/8 to 1/2" dia. rods). You can draw one or two arcs off the
metal to each electrode, or use an indirect arc above the melt. Figure a
half hour melt time and remember to adjust the electrodes, as they will
vaporize! Get good clamps, too- nothing worse than melting the electrodes
off the wires!
Speaking of electrodes, they'll give a reducing atmosphere of CO and carbon
vapor in nitrogen, so argon isn't really required.
Deep Fryer: a very philosophical monk.
That's a;; about right.
So, the idea is to just use the arc as a radiating source of heat,
I see. Very interesting. I will look around for suitable materials,
sometime later. I want to finish an interesting project that
Very nice. CO, though, is not a fun gas.
Nah..not really. It burns off suprisingly well once it gets outside.
I've seen a lot of it, for example when adding a load of charcoal to my
furnace (when I used the charcoal fired furnace), the flames from below
would choke out on the cold fuel above and give off lots of CO, which burned
above in wide, thinly blue, whispy flame. Wish I had a picture of it!
Deep Fryer: a very philosophical monk.