Thermometers and PIDs

[TXTad]

I'm getting serious enough about casting that I need a thermometer. I also know that I need a PID on my pot. I'll get there. In the meantime, do we like the Lyman digital, or should I get a analog one, or both?

The Lyman in question:
https://www.amazon.com/Lyman-Digital-Lead-Casting-Thermometer/dp/B01MZ7O109

[Maven]

I've been using Tel Tru (analog) dial thermometers for 25+ years and find them to be quite reliable + no batteries, probes, or wires to worry about.

[GregLaROCHE]

Strongly consider a PID if you want to keep close control on your lead temperature.

[Mk42gunner]

I've used a tel tru manufactured thermometer for several years, I don't remember if it is marked Lyman or RCBS. I haven't used it for four or five years though, I had a large enough supply of one alloy that I just set my pot dial and left it alone.

It is not calibrated, but it works well enough that a few degrees aren't going to matter.

One thing about the bi-metallic thermometers is there are no batteries to go bad and ruin it.

I have not gotten a PID yet, maybe one of these years.

Robert

[dannyd]

I have that Lyman Digital Thermometer and if I was you I will put that 35.00 dollars towards a PID unit. I have Three PID's and love them. Look up Hatch in the Vender for sale section; he makes a quality product well worth the money. You can also use the PID as a thermometer.

[Sasquatch-1]

This is about $30.00 on Amazon.

https://www.amazon.com/Tel-Tru-LT225R-Replacement-Thermometer-degrees/dp/B0055777EU/ref=sr_1_3?crid=3DZ5E9RGKHDI8&keywords=1000+degree+lead+thermometer&qid=1674134218&sprefix=1000+degree+lead+thermometer%2Caps%2C66&sr=8-3

[Hossfly]

The main thing with a dial thermometer is they are most accurate in the middle of their scale, not so much at the bottom or top. Also get one you can adjust, some have a hex nut on bottom of dial that can be held with wrench and dial turned to fine tune the indicator. Also analog thermometers don't have a cussedness of a battery. But on the other hand you lose the ability of reading temp out to tenths or even hundredths of a degree, if that matters.

[OS OK]

Go with a PID to control the pot...why half-step?

But if you do half-step, go with a digital thermometer as they are fast...analogue is slow to indicate temps.
If you pay attention to either method...you will be surprised at how much that pot will vary, especially so when putting sprue cuts back in...don't do that while casting :bigsmyl2:

[huntinlever]

I got my analog thermometer from Rotometals, and I am very happy with it. I have a Lee Magnum Furnace but still confirm temps with it.

For those of you who use PIDs, while not using them in casting, I've built quite a few for brewing and cheesemaking, including making and cellaring on both. Better for maintaining cellar temps, I've never been satisfied with temp control during mashing, or raising milk temps to fabrication stages. Mostly, overruns, even if setting parameters more tightly.

Probably not as critical here, but do you guys have issues with overrun temps?

[Froogal]

I've never felt the need for either one. When the lead flows into the mold, it is hot enough. If the bullets come out with a frosty appearance, it is too hot. If the bullets have wrinkles, it is not hot enough.

[TXTad]

I went ahead and ordered a RotoMetals 1000°F dial thermometer.

I'll see how I do with that before deciding on the PID, which I'll probably get anyway eventually.

I gave my old Lee bottom pour pot a good cleaning. It came to me used and has a little bit of rust in the bowl. I did the best I could with a scotch-brite. I took the valve rod out and cleaned it up well and did the best I could with the spout. It's not perfect, but it's quite a bit better now.

I poured a few Lee 429-214 and Lyman 429383 last night and it was a bit easier than before I cleaned up the pot. I still can't seem to get good fill-out unless the bullets come out with a hint of being frosty, so a thermometer may help a little to figure out what's going on with that.

[dannyd]

If your Lee pot is a 20 lbs one; this worked for me to stop the drip. I use a Lyman 25 and RCBS pot now, but did use Lee pot for about 20 years.

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[lightman]

A thermometer is one of those things that you can do without but thats nice to have. I cast for a long time without one and finally bought an RCBS analog 1000º thermometer when Midway put them on sale years ago. I run my ProMelt on a PID now and reserve the RCBS thermometer for my smelting pot. Its nice knowing the temp!

[Bentstick]

+ On pid controlled made my life easier, and casting more consistent.

[Sasquatch-1]

I gave my old Lee bottom pour pot a good cleaning. It came to me used and has a little bit of rust in the bowl. I did the best I could with a scotch-brite. I took the valve rod out and cleaned it up well and did the best I could with the spout. It's not perfect, but it's quite a bit better now.



When cleaning the pot, take an old brass brush on a short piece of cleaning rod mounted in a drill. Run this around the sidewalls of the pot. Harbor freight sells small brushes that will fit in the spout although a paperclip will do the same thing.

[JonB_in_Glencoe]

I recommend both for a Lee pot...here's why.

I've found that a analog thermometer is a good tool for casting with a Lee, as the alloy will get hotter as the level gets lower. The Thermometer will tell you the status and allow you to adjust the temperature control during your casting session.

Now, a PID on a Lee pot, solves the problem of temp change as level lowers. A PID will maintain a constant temp throughout your casting session, Making it a wonderful solution to a troublesome problem that the Lee has.

If you build your own PID controller, then a analog thermometer is a good thing to have, to double check your PID...until you trust your build.

Good Luck.

[jeepyj]

I have that Lyman Digital Thermometer and if I was you I will put that 35.00 dollars towards a PID unit. I have Three PID's and love them. Look up Hatch in the Vender for sale section; he makes a quality product well worth the money. You can also use the PID as a thermometer.

^^^ My recommendation as well^^^

[BamaNapper]

I skipped the thermometer step. I picked up a PID controller and appropriate thermocouple from eBay a few years ago. It took me a couple hours to cut up an old project box and get it all wired up using part of an old extension cord I had laying around. I could have spent $30 for a thermometer, but instead spent the same $30 to build the PID. It works great. It took me a little experimenting with the different alloys, but I now know the temp setting I need for each that works with my casting tempo and the molds I'm using.

[Walter Laich]

▲ I built my own PID, too. Easy with instructions for this site.

only problem is after casting straight for 45 minutes making 200 gr RNFPs my pot is usually empty :smile:

[Larry Gibson]

The furnaces (Lee, Lyman and RCBS) that I am aware of all have the heating element around the circumference of the pot at the bottom. With my Lyman Mag20 it means if I have a PID or thermometer on the top half of the alloy it can show a very low temp when the pot gets half empty. Turing up the pot only increases the temp on the bottom half so that temp can be considerably too high.

I use two thermometers of two different lengths. One measures the temp of the bottom half of the alloy and the other the top half. I can easily moniter the total alloy temp that way and add alloy when necessary or adjust the thermostat to maintain the casting temp I want.

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[popper]

I just stick my PID probe in the liquid alloy so it measures alloy temp. It does overshoot when melting but holds temp @ 725 where I set it during casting.

[huntinlever]

Convinced.

[dannyd]

PID's work for heating your sizer too.

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