Lee Pro 4 20 furnace ?

[edmehlig]

For those who have a Lee Pro 4 30 Furnace, what setting 7, 8, 9 or Hi do you use to get your lead to the correct temperature? I'm using either pure or 40:1 mix lead and cast 465 gr connical bullets for my ML.

Thanks..Ed

[birdadly]

I've read here that it ranges from pot to pot. I believe the only answer is for you to get a pot thermometer.

I've only used my pot 3 times so far, twice with a thermometer now, and it seem quite finicky. I've started around 8, but then once it's molten, it seems to stay at a nice temp for some time, even with me lowering it down to like 4. I wish to make one of those PID things you may read about here; they seem way nice. -Brad

[dragonrider]

Yup no two are the same in my experience, a thermometer will end all doubt.

[Mk42gunner]

Mine is setting between 7 and 8 right now, that usually gets me pretty close to the right temperture. I use WW and vary the dial according to the Lyman thermometer.

The temp will rise as the alloy level goes down, so I don't have to worry about it once the boolits are dropping right unless I don't add ingots to keep the pot full.

Robert

[Sonnypie]

I run mine at 7-7.5 normally.
My new thermometer is in the mail as we speak.
If you want one, from a forum sponcer, I'll pass along what Gearnasher passed along to me:
NOE Lead pot Thermometer (http://castboolits.gunloads.com/showthread.php?t=102777)

I was kind of torn about getting a pot thermometer. But I think you should have one.
Whether or not you use it all the time, or just during the learning curve for YOUR furnace, is up to you.
But without one, it's a guess at best.
Good tooling pays you back.

But I'm a sprout at this. I only have about 4000 bullets under my belt so far. :castmine:

[edmehlig]

Thanks for the replies. What temp is recommended for 40:1 mix to pure lead?

[shotman]

ed your fill out will tell you that. pure dont tend to frost. unless you heat it real hot

[HDS]

For those who have a Lee Pro 4 30 Furnace, what setting 7, 8, 9 or Hi do you use to get your lead to the correct temperature? I'm using either pure or 40:1 mix lead and cast 465 gr connical bullets for my ML.

Thanks..Ed

According to my temp the pot likes to run hot even when I got it down to the 2nd setting when its full, then as it empites, the smelt gets cooler and I gotta up the heat, weird. I got a NOE thermometer as well.

[Old Caster]

A Lee pot has a rheostat which varies how much electricity goes to the elements at any given time. In other words it is not off and on like a thermostat. For this reason the temperature will get to be less and less at the same setting as the rheostat wears because the connection at a given temperature will become less from wear and eventually fail and the hotter the pot is kept the quicker the failure will occur. Their rheostats are cheap and easy to replace however so it isn't much of a problem. The reason I don't use a Lee pot is because it is too difficult to keep the temperature the same and if you want real quality bullets for competition, it is pretty important. -- Bill --

[Mal Paso]

For a couple bucks more than a thermometer you can build a PID Controller. http://castboolits.gunloads.com/showthread.php?t=115724 I've seen real deals on this forum if Auber ($100) is over your budget. :coffee:

[Frozone]

A Lee pot has a rheostat which varies how much electricity goes to the elements at any given time.

The modern 4-20 pot does NOT use a rheostat! A rheostat is a current modulating device, you have one in an analog volume controls for your TV or radio.


It has a temperature sensitive Thermostat (http://leeprecision.com/xcart/THERMOSTAT-110V-20LB.html) Just like all the other (lyman,rcbs,seaco) pots do. The difference in the LEE is the thermostat is in an aluminum box and it does not directly read the lead temp.
This means that as the ambient temp, wind, ect. effects the Al housing, It will also effect the thermostat's setting.

[Mal Paso]

The modern 4-20 pot does NOT use a rheostat! A rheostat is a current modulating device, you have one in an analog volume controls for your TV or radio.


It has a temperature sensitive Thermostat (http://leeprecision.com/xcart/THERMOSTAT-110V-20LB.html) Just like all the other (lyman,rcbs,seaco) pots do. The difference in the LEE is the thermostat is in an aluminum box and it does not directly read the lead temp.
This means that as the ambient temp, wind, ect. effects the Al housing, It will also effect the thermostat's setting.

Actually it isn't a rheostat or a thermostat it's an Infinite Control like an electric range. While the contacts are closed and electricity is going to the heater, a Resistor heats a bi-metal strip attached to the switch contacts. When the bi-metal switch gets hot enough the contacts open stopping electricity to the heater and Resistor. The bi-metal strip cools and bends the other way until the contacts close and heating starts again. The heater is full on or off, just the on time changes and the Adjustment knob applies pressure to the bi-metal strip to change on time. The switch is somewhat affected by the temperature of the pot but not enough to consider it a thermostat as the switch generates most of it's own heat. No two people have the same temperature setting because no two people have Exactly the same switch.

And it's so 1940s

Go to the the "Project-PID on Lee Pro 4 20 furnace" Sticky above. You don need no estinking thermometer.

[2wheelDuke]

I turn mine up to full until the alloy starts melting, then I back it off and check with Dad's old thermometer.

I'm casting with it down around 6 or so.

[timkelley]

Mine starts at 7 and I back it off as I cast, depends on what boolit I am casting.

[Sonnypie]

Since I got mine therminomommeter (say that 10 times fast) I cast about 500 30 cal boolits in the last session. (Lyman #2 alloy)
It was fun and interesting to learn what I had been doing WRONG so far. My Pro 4-20 will bob along at 850 F at a setting around 7-7.5.
As things went along casting, I kept reducing the heat until I was getting fairly fast setting of my sprue at 650 F.
So back up to 700 F, and I was happy with my boolits, at my cyclic rate of pouring.
My furnace pulses along with longer pulses during warm up, and much shorter ones during working. And it holds well. Well enough for a lump that is going downrange and likely to never be seen again.
But without a thermometer, you are shooting into the dark. Even with a PID controller. You have to have references to check things. Just to see if everything is in the ball park. ;-)

[MikeS]

As others here have said, a thermometer is important to have. It's important when using ANY pot, not just a Lee. Using a PID controller is an even better way to go for controlling the temp of you lead, but it's more of a luxury item, where a thermometer is really a necessity item IMHO.

[41mag]

Well since getting my thermometer, I have found a few things out while pouring up my boolits.

When I get ready to pour I fill the pot with ingots and set the knob to 6 and fiddle with getting everything else ready until things get slushy. Then I start to stir and flux. Once fluxed I set it to around 4, and get ready to pour. This usually leaves me with the alloy temp in the 650'ish range and it will creep up if left alone. Once I start throwing boolits however I usually regulate it down a bit as the level drops.

Before I got it I had made a few marks on my dial settings showing between around 4 and 6 being what to use with different molds to get them to fill out properly. However since getting the thermometer I have found that my above method was like sad a shot in the dark. With the pot full within a 1/4" of the top, the thermometer settled out at 750 with the setting on 5. When I cast using the same techniques as before I found that my boolits came out pretty frosty and I had to keep an eye on my alloy to be sure I had it stirred and fluxed more often.

Since getting the thermometer, and regulating my temps in the range between 650 and 700 on the high end, my boolits have all come out better, and my alloy has not needed the attentions it did when I started out.

I also have the mold thermometer as well ans I use this to keep my molds at or around 325 - 250 which seems to be the sweet spot for fill out and frosting, with my pour rate. This is using the Lee 6 bangers and pouring 200 thru 300gr .452 boolits. This range of temps keeps my boolits very consistent in both size and weight from start to finish with the WW alloy I am using.

Just my situation your will probably vary.

[Mal Paso]

Before Anything Else a PID Is a Thermometer. More accurate than any analog like lyman. If $30 is all you have to spend at the moment analog is better than being without. I am climbing the equipment ladder too. What I am saying is for a few bucks more you can have unbelievably tight temperature control. If I were to do it now I would get a PID first and a second PID or Analog Thermometer for backup.

I have one of those $7 K probes permanently mounted in both my Lee 4-20s, 1/2 inch off the bottom and right next to the spout. I don't throw sprues back or add alloy during a session. I think Gear is right about introducing oxides. I get tight temperature control right to the bottom.

( I use the mold guide and allow 3/8" between the mold and spout. Alloy 95/3/2 @ 730 degrees F running a single 4c H&G 503 mold. I preheat the mold. Still looking for better ways. )