i would like to ask if anyone out there has tied to adapt a
pyrometer to a hand held crucible for torch melting?
Yes, I have… What you will find is that if the Thermocouple goes
into the top of the crucible, It gets affected by the Torch flame
hitting the thermo-well no matter what the thermo-well is made of.
This gives you faulty readings… You could play around with this
idea and get frustrated… You could drill a hole into the bottom or
side of the crucible and you will end up with the crucible
temperature… Then have all the fun of connecting the wires in a
manner that won’t allow them to break.
What are you going to do when you change Crucibles for different
metals ? If you are not changing crucibles for each of your metal
alloys, your metal will not be the correct Karat and will suffer cross
Optical pyrometers won’t help much as the flame from the torch will
give the wrong readings.
If you could heat the crucible from Underneath, then, you could use
a thermocouple in the top…
But… the side effect of this is that you will use a massive amount
of gas/ oxygen and the entire process would be a royal pain. Again,
you would need a different thermo-well and crucible for ea. metal.
With torch melting, you don’t need to read the temp… you need to
pay attention to how the metal melts, when the metal is nearly ready
and anticipate having the flask on the casting vacuum table or
centrifugal machine at the correct time. For Vacuum casting, you want
the metal to have just melted when the flask is put on the Vacuum…
Bring the crucible over with the torch on the metal… sprinkle some
borax to clean the surface… now, the surface should look like a
mirror and it’s ready… Pour it !!!