Inexpensive digital thermometers for smelting

[901S]

I have only smelted wheel weights 3 times, so I am a beginner. Although I do examine wheel weights I would like to not have to be so concerned there might be zinc that I missed. As of now I'm only smelting 5 to 10 lbs at a time, so the molten metal is not deep in a 10" cast iron pan.

I would like to be able to dip a digital probe into the molten metal and have a temperature in 3, 4, 5 (at most 10) seconds. The depth in the pan might only be about 1" so a probe that should be in several inches is not an option.

From my automotive days in the 80's and 90's I have Fluke meters and can buy their thermocouples, but they are rediculously expensive for my limited lead smelting use.

Can you recommend a viable **DIGITAL** meter and probe that I can dip into the molten metal (or even leave in the smelting pan) that is not very expensive? Accuracy is not my issue. Just avoiding melting zinc is my only concern.

TIA

[redhawk0]

Make a PID unit. It will read your temperature digitally. Of course it won't control the smelter if its in a pan using propane for a fuel source, but it will still read the temp.

redhawk

[901S]

I'm using propane. Even if it was electric I don't want a PID for this. I want a standalone digital thermometer. Preferably something reasonably usable and not super expensive.

[bangerjim]

Check the world’s source for everything...........Amazon. Just be sure the range covers the melt temps you anticipate using.

I presonally do NOT use any kind of casting thermometer. Not needed. Experience is the best thermometer. Only one in my PC baking oven to check the survey range.

If you get any of those K t/c’s, they will plug into your FLUKE as long as you have the FLUKE connector! Those ChiCom t/c’s on ebay are dirt cheap. Those cheap t/c’s are what all this PID madness is based upon. A good quality American-made t/c will cost you $100-150........I sell them!

Bangerjim

[marlin39a]

I've got the Lyman digital. Works for me.

[JonB_in_Glencoe]

I've seen a few super cheap (like $5) high temp controllers (not PID style) come with a probe, but that probe is not suitable for smelting lead alloys.

BUT you can get a PID that comes with a suitable/protected K-type TC probe, and use it just for temp reading, for about $12 on flea-bay.
just search "PID temp controller K type"

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Also, you could buy a cheap K type thermocoupler for $5, that will work on most multimeters, if you still have your Fluke? You will probably have to make a protective sleeve for it.
just search "Tekpower TC-1 K Type Thermo Probe for Multimeters "

[Dragonheart]

901s, you really don't need a thermometer or PID for smelting, when it melts it melts. Debris floats to the top. Flux the metal before you cast your ingots so it blends.

[bangerjim]

Glad you said that!^^^^^^^^^^^^^^^

I agree 120%.

Experience counts......PID’s don’t.

[Geezer in NH]

Melting scrap? I melt till it is all liquid then flux it a couple of times, skim and make ingots.

When I have clean ingots, that's what I have tested to see what they are. I have a big advantage my buddy is a metal scraper and he shoots them with his gun that tells what every thing is in the ingot.

It costs me a couple shots of single malt he would have anyway.

All a thermometer will do is give you a guees if you pay attention ALL THE WAY. Sorry but that has never happened for me it goes from slug to melted without my visible attention. Some can do it but not me.

[Dragonheart]

Getting clean ingots is much prefered and that is the reason when I made my smelting pot I made it a bottom pour.

[wjham77]

Ebay, search k type thermometer, some under $10, and some look identical to the Lyman digital one. If its cheap, its made in china, and can be found on ebay, amazon, wish etc , even cheaper.

[Dragonheart]

There is a reason they are so cheap.

[bangerjim]

There is a reason they are so cheap.

YES! Mine cost on average, $100-150 per t/c. But they are accurate, come with an NIST cert, and have a 1 year warranty! Industry demands quality and repeatability. Hobbyists don’t give a carp.

Banger

[randyrat]

Keep in mind, the temp difference between top of the melt and where it touches the bottom of the pot can very. This is why I don't use a thermometer.

To prevent the melt, slurry, lead from getting too hot, STIR the bottom of the pot, at the right temp the floaters will float up and you will notice a change in the lead fast, hurry and scoop out the turds. If you do this you will never melt any Zinc.

Also to prevent lead in your scrap, dip your slotted spoon a bit before you scoop, keep it hot, lead won't stick to it.

[William Yanda]

It is not digital, but I found-after advice I got here- a barbecue thermometer with a 6-8 inch stem. It confirms 450ish melting point when I melt pewter and goes past lead melting temps. Around $10-12 as I recall.

[901S]

Keep in mind, the temp difference between top of the melt and where it touches the bottom of the pot can very. This is why I don't use a thermometer.

To prevent the melt, slurry, lead from getting too hot, STIR the bottom of the pot, at the right temp the floaters will float up and you will notice a change in the lead fast, hurry and scoop out the turds. If you do this you will never melt any Zinc.

Also to prevent lead in your scrap, dip your slotted spoon a bit before you scoop, keep it hot, lead won't stick to it.

Understood, but until I have some more experience I will feel more comfortable with a thermometer.

I stumbled upon a Lyman digital from Amazon warehouse for $18 shipped. (yeah I know it has mixed reviews, but I can ship it back if it doesn't work well). Got it today. Over less than a minute I warmed it up with a torch to 700+ and it worked fine. Will compare it to a Lyman mechanical when I have time.

For now I plan to use the digital when smelting to take a occasional readings in my smelting pan. I will use the mechanical in my Lee 4-20.

I view it no differently than using a torque wrench. Initially it is necessary, but over time with experience it becomes less necessary. There was a time a couple of decades ago I could torque with feel to within a few foot pounds (or inch pounds). When it was critical I continued to use a torque wrench, but for day to day stuff I found I did not need it after years of experience.

[901S]

Tried the Lyman digital for a few seconds while smelting lead with poor results. Wide temperature fluctuations over short periods of time. Then tried it alongside a Lyman mechanical in my Lee 4-20. Same problem. This Lyman digital lives up to all the negative reviews I have read. Back it is going to Amazon.

[EDG]

Check your digital with boiling water for another data point.
If that is off you have a terrible instrument.

[KenT7021]

Call Lyman customer service about the digital thermometer.They will ship you a new one no charge.They normally work fine.