Lee pot + thermocouple

[Junior1942]

Anybody ever rigged a thermocouple control to a Lee pot? Looks to me like it could keep the melt temperature +- 25 degrees from the setting. You could drill & tap the side and permanently attach a thermocouple or you could take a removeable guage such as the Lyman and rig a tiny RF transmitter keyed by a magnet on the guage needle.

[Frank46]

junior, back when I worked for a living we used to epoxy thermocouples to some of out oil lines. We had this gizmo that read out in degrees when connected to the thermocouple. Any of the plastic steels won't work as the high temps will destroy the resins in the epoxy. What you may need is something like the stuff thats used to repair exhaust manifolds. Try eastwood as they just might have a high temp epoxy. Oh yeah, regular plastic steels with resin will leave on heckuva smoke trail. One guy at work used one on his car to save a few bucks. Looked like a destroyer doing 30knots
and had the fuel air mix wrong. Frank

[Junior1942]

Frank, I've found a couple of places online with screw-in thermocouples which will work in molten lead. However, they're about $400. That's about $390 too much!

Looks like the way to go might be to add a magnet and a transmitter to a Lyman thermometer.

My idea is to build a maybe 6" X 6" box with a male electrical cord on one side and a female electrical plug on the other side. Plug the box's cord into the wall. Plug the pot into the box.

The box contains circuitry which, via a triac, supplys 110 VAC to the Lee pot. The circuitry triggers the triac via a signal from the tiny transmitter on the Lyman thermometer.

[Frank46]

Junior, I may be wrong but seem to remember that heat can destroy a magnets magnetism. Your contact with the thermocouple will most likely have to be a physical one. Maybe try band clamps like those for auto water hoses only bigger. Just curious,why go through all this trouble to try and get a more consistent pot temp?. Maybe I missed something. Frank

[kenjuudo]

Frank you are right, heat will destroy a normal magnet, but a rare earth magnet will hold up, and they are among the strongest for their size.

Junior, ya get to the point of constuction I'll mail ya a couple magnets to play with.

jim

[HTRN]

Why go to all that trouble? why not just make a clamp arrangement that holds the thermocouple in the molten lead?


HTRN

[Junior1942]

>Just curious,why go through all this trouble to try and get a more consistent pot temp?

Because a consistent pot temperature means a consistent bullet.

>Why go to all that trouble? why not just make a clamp arrangement that holds the thermocouple in the molten lead?

Because a screw-in thermocouple would be more permanent.

If I could figure out the thermocouple problem, I think this thing could be built for less than $50. One big advantage to using a probe like the Lyman guage is that the control unit could be easily installed into another pot. Just stick the guage/thermocouple/transmitter into the new pot and plug the new pot into the control box.

[Frank46]

Junior, not to get you off track but sears sells a infrared temp measuring gun for about $90.00. I'm pretty sure that if you check other sites you may get one for less.
Frank

[Oldfeller]

Doesn't anybody else 'round here cast fast enough to cause their LEE pot to climb up to the full "on" postion and the pot temperature is then being completely metered and paced and controlled by the melting of the continuously added ingot and just barely hardened as dumped back in sprue lines?

By definition, your pot must stay exactly at the melting point of your WW alloy, extremely consistent "free" temperature control as one extra erg melts one dollop of alloy with ZERO temperature change of your liquid pool of metal.

Your alloy pool can't change temperature appreciably until your lead is all melted.

You guys are really talking about variation in your MOLD temperature, not your lead pool -- and Bruce B. has a method of keeping that lowered synthetically as well.

<g>

Oldfeller

(I'm talking six bangers molds of course, I would never admit to owning a ****ty LEE two banger or one banger mold ever again -- it would be like admitting to a having a mental deficency if you did)