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View Full Version : Lead Thermometer?


Jector
October 11, 2009, 10:09 AM
Well I've been bitten by the casting bug... I've ordered some of the basics, pot, mold, handles, and was wondering about lead thermometers. I see Midway has a couple a Lyman at ~$32 and a higher-rated (more stars) RCBS at ~$50. These prices got me thinking... How about a non-contact IR thermometer like this one...
IR Thermometer at Amazon (http://www.amazon.com/Mastercool-52225A-SP-Temperature-Thermometer-Immersion/dp/B000OCKHGQ/ref=sr_1_1?ie=UTF8&s=automotive&qid=1255272975&sr=8-1)

For $40 bucks more this would seem infinitely more versatile, could even use the thermocouple probe to monitor the Thanksgiving turkey (so long as I didn't stick it in lead beforehand).

Has anyone used one of these for molten lead? I'm guessing it would work fine as long as there is not a stagnant crust floating on top insulating the lead from the surface reading. Seems that a stir or a skim would solve that problem. Also, would it be useful to get a temperature reading of the mold from time to time, to avoid frosted bullets from a too hot mold?

Crosshair
October 11, 2009, 10:22 AM
I'm guessing it would work fine as long as there is not a stagnant crust floating on top insulating the lead from the surface reading.
In a lead pot you are going to have a coating of oxide on the surface. It's good to leave it there and let it build. It prevents further oxidation and does provide a layer of insulation. Your temp readings will not be accurate without an immersion probe. If you skim it off another layer will quickly form.

Also, would it be useful to get a temperature reading of the mold from time to time, to avoid frosted bullets from a too hot mold?
Frosted bullets are not an issue. If anything they tend to make the lube stick better. I only have a simple RCBS Immersion probe and It is easy for me to control the melt temperature to keep the mould at the proper temperature.

For $40 bucks more this would seem infinitely more versatile, could even use the thermocouple probe to monitor the Thanksgiving turkey (so long as I didn't stick it in lead beforehand).

The moment you stick the probe in lead is the moment you no longer use it for food. Same reason why you don't use the toilet brush in the bathroom to wash your oversize pots and pans.

I'm nerdier than most, but you are really over engineering this. Get an RCBS immersion thermometer and call it a day.

Pahoo
October 11, 2009, 11:37 AM
You need to consider the "Range" of the temperature probe. In this case, You will need an upper range of 850deg. F. or higher and most kitchen TI's do not have this range rating. The lower range will not start at 0Deg.F. but much higher. Will have to look at the Lyman to see what it's range rating is as I only use a digital TI. Good luck and I too would suggest a dedicated TI for casting.



Be Safe !!!!