In article , Jim Wilkins
wrote:

"Joe Gwinn" wrote in message
...
In article , Jim Wilkins
wrote:



http://www.ctmuzzleloaders.com/ctml_...tempering.html
The thermocouple adapter on his DVM looks like an expensive Fluke
80TK. The inexpensive TM-902C thermocouple readout I would have
suggested is out of stock at Amazon. Omega's GG-K-24 thermocouple
wire
is a good choice to make your own. Wood stove gasket cement will
bind
the cut ends of the insulation. Do you have or know someone with an
acetylene torch to fuse the end?
http://www.omega.com/pptst/XC_K_TC_WIRE.html


No TIG required. The old hack is a 100-watt incandescent lamp in
series with the TC and a carbon rod from a D-cell, across 110 Vac.
The
TC wires are twisted together, heated in a flame, and dipped into
borax.

The arc from the lamp turn-on surge will weld the ends of the wire
together. Tap the weld bead with a hammer on an anvil to crack the
fused borax off the bead.

What also works is a charged photoflash capacitor discharged through
the same twisted wire and carbon electrode.

Commercial TC welders are the photoflash capacitor et al, but with
an
argon blanket and no borax.

Joe Gwinn

How do you safely clamp everything into position?

The TC is held in a vise, and the carbon is held in an insulated holder
which is held in hand. There is 110 Vac between vise and carbon, with
the 100W bulb as the current limiter.

The vise should be clamped to a wooden bench, and ideally is on the
cold side (white wire in the US) of the 110 v line and the 100w bulb is
in series with the carbon rod, so if carbon touches the vise, the bulb
lights up, but no big bang.

Joe Gwinn