So I looked on the web, but there is no Thermotrol. If this type of unit is so good, why are they not in the catalogs? Are they extinct?
Thermotrol machines, if I recall correctly stopped being made
sometime in the early 80’s. Dunno why, or who made them. One of the
dental machine manufacturers, I think. I do recall something about
their reputation though. They did a decent job, melting metal in much
the same way the kerr electromelt furnaces do. The graphite melting
crucible helped much with oxidation of the metal, reducing some types
of porosity. The trouble with them was that the graphite crucibles
weren’t cleap, and didn’t last long, and like some of the
electromelts, sometimes tended to overshoot the desired melt temp
before settling back down to the setting. So some alloys would loose
more of their deoxidizers than with torch melting, which mostly
affected how much new metal to old metal you needed to use. I might
be remembering this last bit wrong, but that’s what I recall…
Hope that helps.