Casting thermometer

[Gundogblue]

I’ve just gotten back into casting after a 37 yr layoff . I just bought a Lee production pot that holds 10 lbs of lead, my question is, is a casting thermometer really necessary? I ask this because I read that 700 degrees is about right for casting, and with the heat control on the Lee furnace it goes from 1 to 10, it’s almost like guessing which temp setting is right. Any advice will be greatly appreciated.
Paul

[MT Gianni]

IME, the lee temp setting gives you one temp at full pot, +or- 100 F at half full and who knows what in between. Many cast without one. I like one for it's repeatability.

[Acidia609]

MT Gianni is correct. Also Temps vary between pots. What I do for me at first is crank the pot to 8 untill it melts throughly. Flux with saw dust then dial down to 5, Wait for it to cycle then go to town. 5 seems to be about 680-700 ish.

If you really get back into it and want better results I'd suggest building a PID controller. Cost is not very much more then a Thermometer and boolits become more uniform and easier to cast. Johnny Reloading Bench has a great build series here:
https://youtu.be/AgixJeF0vEU

Or if your computer savey you can build a self contained unit like I did using Arduino. Its a little more cheaper:
https://youtu.be/Mh-85vxrT3o

[trixter]

I started a Lee pot and then an RCBS, (which was borrowed) and then I bought a Lyman Mag 25. I had a manual Lyman casting thermometer and then the temp control on Mag 25 and then purchased the Lyman Digital Lead Casting Thermometer, which was only about 5° off from the Mag 25. The manual Lyman was way off, so I set it right in between the other two. Now I am pretty sure that my melting temps are very close to what I want. Having the ability to regulate the temp of what I am melting helps a lot to make accurate boolits.

[mdi]

I have one, somewhere. I got it for Christmas a few years ago and used it a few times. I wrote down the temps for specific molds and kept that data in my Casting Log. Soon I reverted to my methods used for 14 years prior to the thermometer and just watch what the bullets look like as they drop outta the mold...

[Boolseye]

My Lee 4-20 will go over 900º if I keep it set at 7. Maybe 1000.
My pot "idles" between 3-4 after getting up to temp and keeps the temp right where I like it, between 700 and 800º
I use my thermometer whenever I cast.

[lightman]

A thermometer is nice to have but its not strictly necessary. Its just one of those tools that can make life easier. If you decide to get one, look at the Tel-True.

[10x]

Build a PID. Set the temperature on the PID and never worry about alloy temperature again. More accurate than a bimetallic thermometer and the Sam price or less

[John Boy]

Gundog - to maintain a small Bell Curve of the bullets for a casting session, a thermometer is needed to maintain the pot melt at constant temperature
Spend the money & enjoy ... https://www.teltru.com/p-272-big-green-egg-primo-komodo-grill-dome-or-other-kamado-style-replacement-thermometer-lt225r-5-inch-stem-2001000-degrees-f.aspx

[Boolseye]

I got mine from Rotometals back when I started casting. They were selling the same one that RCBS uses but with no markings. Have never had a problem with it in 7 years of steady use.

[country gent]

While not a real have to item the thermometer helps you to "know" for sure where your at and to replicate results with a given alloy and mould. Its a nice tool in the box for making things easier and trouble shoot when problems arise.

[slim1836]

I stopped using a thermometer once I built a PID. It compensates for the lead level drops and fill-ups so you know what the temp is at any time. Call me spoiled, but I will only use a thermometer if the PID quits, and only until I fix it.

Slim

[RED BEAR]

Lee pots heat up as lead levels fall so would recommend one I use an rcbs and seems to do a good job. My Lee pot will go a good bit over 1000 degrees .

[Gundogblue]

Thanks for the info, Midway has the Lyman digital on clearance right now for about $15.00 plus shipping. I just ordered one.
Paul

[Walter Laich]

As noted above it makes the production of lead bullets easier and for me that up's the enjoyment factor and as this is a hobby I want to maximize that happiness wherever I can

[Ed_Shot]

Gundog - to maintain a small Bell Curve of the bullets for a casting session, a thermometer is needed to maintain the pot melt at constant temperature
Spend the money & enjoy ... https://www.teltru.com/p-272-big-green-egg-primo-komodo-grill-dome-or-other-kamado-style-replacement-thermometer-lt225r-5-inch-stem-2001000-degrees-f.aspx

+1 If you are not going to build a PID this teltru is the way to go.

[mdi]

Reading all the replies I'm impressed how complicated we can make a simple process. I believe buffalo hunters used a frying pan over a wood or buffalo chip fire and cast plenty of good bullets (they managed to wipe out millions of buffalo with them). I started casting with a Coleman stove and got plenty of good bullets for my 44 Magnums. Now we "need" electronic temperature controls for electric melting pots to keep temps withing a 10 degree spread, just to cast lead bullets...:popcorn:

[Mike W1]

And I prefer the modern automobiles to the Model T

[10x]

Reading all the replies I'm impressed how complicated we can make a simple process. I believe buffalo hunters used a frying pan over a wood or buffalo chip fire and cast plenty of good bullets (they managed to wipe out millions of buffalo with them). I started casting with a Coleman stove and got plenty of good bullets for my 44 Magnums. Now we "need" electronic temperature controls for electric melting pots to keep temps withing a 10 degree spread, just to cast lead bullets...:popcorn:

Minute of buffalo was needed back then. About the size of a wash tub.
Our current needs reflect our personal goals. Some of those goals are under an inch or less with bullets that are 0.220" in diameter and under 40 grains.

A Coleman stove has a great deal more control than casting over a fire of buffalo chips.

The whole purpose of a PID controlled electric casting pot is to make casting an almost perfect bullet less complicated.
Plug it in, get it up to temperature, and cast. No wondering if those wrinkles are oil in the mold, a cold mold, or a cool alloy.
I cast over a coal fired forge under a cast iron pot in the late 1960s with the need to turn the blower crank every fifteen to twenty seconds to keep alloy heat up. The quality of bullets was not as easy to achieve as today.

[dragon813gt]

Reading all the replies I'm impressed how complicated we can make a simple process. I believe buffalo hunters used a frying pan over a wood or buffalo chip fire and cast plenty of good bullets (they managed to wipe out millions of buffalo with them). I started casting with a Coleman stove and got plenty of good bullets for my 44 Magnums. Now we "need" electronic temperature controls for electric melting pots to keep temps withing a 10 degree spread, just to cast lead bullets...:popcorn:

10 degrees is a large spread and you will have significant weight variations. I try to keep it w/in two degrees. I'm one of the guys that actually cast w/ and w/out a PID and then plotted bell curves. The tighter control of the PID produced significantly less weight variation.

Do you need a thermometer? No you don't but it sure helps. Do you need a PID? Absolutely not but it helps you focus on every other aspect of casting. When you're not chasing temp you can focus solely on cadence which decreases weight variations. You don't need an electric pot but it sure is a lot easier then casting over an open fire.

I prefer to embrace technology because it almost always makes what I'm doing raiser. There are exceptions. I find digital refrigerant gauge to be annoying. I prefer my analog manifolds. But I've been using them less and less since getting a Bluetooth set of gauges. Connects to my iPhone and I can see everything at once. Technology can be a gift and a curse.

[Victor N TN]

I started casting in the mid to late 1970s. A Coleman stove and a steel pot with a covered ladle for pouring into the molds was a big help.

Several years later I got a Lee 10 pound bottom drop leak... er pot.

A few years ago I got a little money from the government. I immediately bought some new molds and a RCBS 22 pound pot and a thermometer. But I've been sick for a little over 2 years now. If I ever get better health, I'll try to use what I have. A PID just may not be in my future.

[country gent]

I still cast over a propane burner and a bigger pot ( 125;bs or so). The frying pan or pot the Buff hunters used would probably fell between the 20 lb electrics and mine capacity wise. My pot once set varies very little in temp, that much mass takes awhile to change temp. Once I get it dialed in and going it runs there pretty consistently. Same as the Buff hunters probably did and as the pot emptied the fire was burning down getting cooler also. Mass of the pot is the big equalizer. I do have a lyman thermometer mounted in my pot to track temps and adjust it as needed. The propane burner don't burn down like wood fires do. But it maintains temps well enough for me.

[Boolseye]

Since we’re on PIDs here, can soneone point me in a good direction on how to make one? I’m no electrician, just mechanically apt.

[lightman]

There are several stickies about PID's. Some of them have parts list also.

[Boolseye]

I did look at a couple of them, one no longer had images. I'll search some more.

[gwpercle]

Victor,
I've been casting 50 years now....I don't have a thermometer or a PID and don't plan on getting one.
You can cast good boolits with a Lyman ladle and open top pot. Just by looking at the bullets you cast you can tell if the alloy is too hot, too cold or just right.
I pressure cast mine and keep the temperature of the alloy so they drop just below or a little frosty.
After 40 years of casting that experience should put you in the " I don't need no stinking PID" category !
Fire up that pot and go to casting...when they get frosty...ease the dial cooler, wrinkly boolits, jack the heat up...don't let no PID or thermometer stop you...it's not rocket science !
Gary

[Boolseye]

...now where'd them buffaloes get to...:Fire:

[David2011]

I’ve just gotten back into casting after a 37 yr layoff . I just bought a Lee production pot that holds 10 lbs of lead, my question is, is a casting thermometer really necessary? I ask this because I read that 700 degrees is about right for casting, and with the heat control on the Lee furnace it goes from 1 to 10, it’s almost like guessing which temp setting is right. Any advice will be greatly appreciated.
Paul

Paul,

There have been many responses and all were valid for the responder. I found that consistent casting got easier when I bought a thermometer. It works and I make boolits that shoot well. Since I use a 22 pound furnace and try to keep it at least half full I don't have a huge temperature swing but I will add a PID one of these days. I want one for my lubrisizer anyway so might as well PID the furnace, too.

You can cast without a thermometer but it's also useful as a diagnostic tool if you have unknown metal, especially if you are trying to determine if it's pretty much pure tin or pure lead as they have known melting points. I always use my thermometer just to keep tabs on what the pot is actually doing.

The bimetal thermostats are inexpensive, less than precision devices and any correlation between the settings between two different pots would IMO be purely coincidental.

Welcome back!
David

[toallmy]

I found the thermometer helpful in casting , and smelting possible not necessary , but very helpful . I originally got a thermometer to use when melting coww to keep the zink from melting . You would be surprised at the temperature swings with a lee pot .

[nun2kute]

For casting out of one of my pots, a PID would be nice. But I am no longer chasing one as "I gotta have" one. But on the other hand, if you are gonna smelt WW for casting I won't ever go without again. I got couple of half buckets of biscuits and bars that I made when I first started casting and didn't get all the zinc sorted out. Too gung-ho without knowledge. So now I use a thermometer to keep just enough heat to melt lead and skim the zinc and $**t off the top.

[mdi]

I figgered I'd get more "Yer full of it" posts claiming I'm stuck in the '30s. But I ain't. I worked for 25 years on Automotive electronic systems on passenger vehicles and electronic systems on heavy construction equipment (from electric Toyotas to 50 ton hydro cranes). I understand working for "new and improved" products and often there is reason (someone mentioned model T vs new auto and some should stick with '30s automotive technology) some for safety reasons. But how much of new technology just robs us of knowledge (I asked my wife where the starter was in her car and she pointed to the key switch) and making us more lazy (I remember the first auto trans car I drove, 5 years after I got my license. Anybody drive vehicle without power steering, power windows, power brakes?). Not condemning new improved technology, just offering my perspective...

Excellent bullets can be cast using a teaspoon as a ladle dipping out of an old stainless steel pot heated over a campfire. if the caster has patience and physical ability to practice...

[dragon813gt]

Excellent bullets can be cast using a teaspoon as a ladle dipping out of an old stainless steel pot heated over a campfire. if the caster has patience and physical ability to practice...
I don't think anyone is saying otherwise. If one wanted "perfect" cast bullets they'd use a single cavity mold. Multiple cavity molds are never cut exactly the same from cavity to cavity. Most people will sacrifice slight variations for the speed of a multi cavity mold.

A PID and Thermometer aren't needed. Just like power steering and a backup camera on a car aren't needed. But they make things easier.

[HangFireW8]

Gundogblue,

Using a Lyman casting thermometer is useful for tracking your own alloys and what temps work best against your molds... but don't expect any meaningful comparisons with other people's thermometers.
http://castboolits.gunloads.com/attachment.php?attachmentid=169543&d=1465014164

[marek313]

There seems to be two different schools as far as casting equipment is concerned.

"Old school" casters can cast perfect bullets with a pot over wood burning stove using some old rusty ladle. That usually requires some time and trial and error to get to this point but it works and many people use simple equipment to cast perfect boolits.

"New school" of engineers and tinkerers likes to use technology with thermometers and PIDs to get better consistency. Nothing wrong with that just expect to pay little more for fancy PIDs and expensive bottom pour smelting pots. This group of people like to tinker just because but to be fair things like PIDs do help.

Me? I'm kind of in the middle I ordered all parts for my PID and I actually got it working just not put together in a pretty box yet. At the same time as I kept casting with my Lee 20lb bottom pour and mostly Lee molds. My thermometer died but honestly I'm to the point that I dont need it nor do I need that PID. If you watch your lead and your molds you can figure out that happy spot that drops perfect boolits.

[wmitty]

Hangfire
You nailed it. Accuracy / variation at 7-800 degrees is obviously ballpark with bimetallic thermometer.

[Gundogblue]

Again thanks for all the advice. My dad never used a thermometer, I remember my dad telling me frosted is too hot, wrinkles are too cold. But my thinking is with a thermometer it will give me a good base point to work with.
Paul

[pworley1]

I have been using a Lee pot since they first started making one without a thermometer and have not had any problems. It is easy to tell from the way the bullets look it the pot is too hot or not hot enough.

[dragon813gt]

I have been using a Lee pot since they first started making one without a thermometer and have not had any problems. It is easy to tell from the way the bullets look it the pot is too hot or not hot enough.

Out of curiosity have you weighed each bullet from a batch and plotted a bell curve? W/ pistol bullets it's not going to matter. W/ 55 grain 22cal bullets it really matters.

The Lee pot can vary by over 100 degrees if left to do its own thing. The 7 setting doesn't mean 750 degrees. That's just a random number. As the lead level in the pot lowers that temp will rise drastically.

I'm not saying you can't cast good bullets w/out a thermometer. Just that if you haven't weighed each one you don't know how "perfect" they are. You will have a larger weight variation if the pot temp isn't controlled.

[D Crockett]

Boolseye if you are having you pot at 1000 deg. you are in great DANGER you are boiling the lead and at that temp you are exposing your self to some dangerous fumes that can do some nasty stuff to your body never let you pot get past 800 deg. for your safety that is why a thermometer is so important in our bullet making D Crockett

[Boolseye]

I never go that high, I was just describing the settings in my 4-20. Also another reason to have a thermometer-thanks for your concern, though.

[Boolseye]

Another consideration is that mold temp is more important than alloy temp for good boolits. With a hot mold I can get good bullets from 650 deg. and up. With a cold one 900 degree alloy will wrinkle.