Faithful Lyman pot slow to heat

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  • Last Post 26 September 2013
Michael K posted this 01 December 2012

I am need of some guidance here. Fired up my 30yr old 20# Lyman pot this afternoon and it took more time than usual to get up to temp or to recover when fresh metal was added. I usually add new metal when down half way and was taking the better part of an hour to get back up to 700F from 500F :taz:

I am trying to determine if it is the heating element or the thermostat that may be the culprit. I am inclined to go with the thermostat. A couple of years ago I had a couple of droplets of lead splatter find their way thru the top vents on the control box on the left side of the pot, has luck would have it it shorted out the thermostat (Murphy's Law in action). After letting the pot cool I removed the thermostat, a few minutes with a file and a dremel things were cleaned up and working fine, at least until this afternoon. Does anyone out there know if there is a suitable 120V replacement thermostat one could pick up that could serve well as a replacement? Lyman won't do squat or even offer any form of suggestion to touble shoot, I have to send the pot in (blah blah blah).

Many thanks for the assistance.

Michael

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onondaga posted this 01 December 2012

http://www.castbulletassoc.org/view_user.php?id=3427>Black and Blue:

I can't understand that, it is practically brand new.

Gary

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Dale53 posted this 01 December 2012

I would try an Industrial Supply place. Remove the thermostat and take it with you if possible so that they can match it.

In years gone by I have done this. However, my supplier is no longer in business so I cannot direct you to a particular place.

Be sure and check the cord inside where it fastens. It is common for a high resistance connection to develop over time, overheat, and damage the connection. It will be obvious if that is the problem.

Good luck! Dale53

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CB posted this 01 December 2012

With Lyman, the trick seems to be to talk with an actual service tech, rather than the girls who answer the main phone. This is how I've been able to get replacement heating elements for my Mag 20 for the last couple of years. Another option may be to bypass the factory thermostat by going to a PID setup. If all else fails, the thermostat in my Mag 20 was made by a company named Robertshaw:

http://www.robertshawtstats.com/Login.aspx

They may be able to sort this out for you too.

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tturner53 posted this 01 December 2012

Or, ask Santa for a new pot.

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Pigslayer posted this 02 December 2012

Bypass the thermostat to see if it heats up quickly. If it does, of course the problem is with the thermostat. If not then you've got an element problem. Go from there. A bad thermostat is easily fixed with a PID if parts are not available from Lyman. A heating element . . . will have to come from Lyman.

If someone else had of done to me what I did to myself . . . I'd have killed him. Humility is an asset. Heh - heh.

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Michael K posted this 02 December 2012

PM sent to “Santa"

Thanks for all if the suggestions. One other query at the risk to sounding stupid, What is a PID set up and how would go about putting it together. I have never tinkered much with electrical stuff much beyond hooking the red wire to + and black wire to - , or very basic stuff

Thanks again, Michael.

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Uncle Russ posted this 02 December 2012

Mr. B & B; PID is proportional, integeral, dirivative control. Glad you ask right? A control scheme that is extremely complex and has been truly mastered by few. For lead melting you use the P and a small bit of the I portion and forget the D. It is all in the programming of the controler when you buy it. Make sure you get instructions as a good portion of the chinese ones do not have instructions and if you get on line to download I hope you are fluent in chinese because they are hopeless in english. Even the Queens own. Even after the Brits lived there for boo-coo years.

Basic settings are preprogrammed but the rest is up to you. Don't let this scare you away as I would help if I can and I'll take a chance to say Pigslayer would too. Better check first on that one.

To start with I go with the poor connection idea as a high resistance connection is off color and even burned looking. Thats an easy fix. Clip it back to a clean area and reconnect. If you use a fork or spade terminal be sure to use a nickle high temp one as a regular one or automotive type will expand on heat increase and make your problem worse. If you need a longer wire make sure it is high temp rated or the insulation may melt and fall off. I know picky, picky, picky. wnk:

A lot of the problems with fixing the old stuff is the old stuff is not UL listed anymore. If it ever was. With obummer and his ilk breathing down everybodies neck no business wants any undo liability. Lets face it UL approval means one item of the same type was tested to meet certain printed standards and passed. Nothing more. These pieces are usually tested to distruction. But in the state of washington the law says you will not install any item that is not UL approved. Other testing agency standards are accepted but damn few, such as Canadian or European. Our shop had a UL standards listing so we could build custom control panels but it is not cheap to belong to the “Good Ol Boys Club".

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gunrunner2305 posted this 28 July 2013

You might look inside the shaft for the thermostat. Pull off the knob. My lyman pot has a screw inside the shaft and when I turned it counterclockwise the heat was much quicker and hotter.

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NORMSUTTON posted this 29 July 2013

this is what I did on one of mine when the thermostat. went out , got a electric box and a dimmer switch, put on the cord , works fine, http://s56.photobucket.com/user/NORMSUTTON/media/bent%20bolt%2038/leadpot.jpg.html>

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Uncle Russ posted this 30 July 2013

To the man from KUNKELTOWN;

The screw you jacked with was the calibration screw. The contacts are now allowed to stay together longer before the spring apart due to heat from current flow. And the control is no longer calibrated.

Sorry but the speed and power is still the same, all that 750 watts can produce, no more , no less. Laws of physics you know.

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Uncle Russ posted this 30 July 2013

Mr. NORMSUTTON;

With nothing in the pot how does it know what temperature the lead is? The world wants to know. So do I.

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Michael K posted this 30 July 2013

I have been pondering that very idea.

Just to make sure we are on the same page, this is what is pictured in my mind. The original thermostat is by-passed by running the power supply through the dimmer switch. The dimmer will control the amount of juice to the heating element in the same fashion it does with lighting fixtures. Then of coarse if the element is toast anyway, I won't see any change in how loooong it take to heat.

Are there any potential problems with re-wiring things with this type of system?

As much as I hate to admit it, my electrical knowledge is pretty well limited to red/white wire, black wire, green wire. Don't cross connect. It's not really that bad, but electrical systems and computers are not my strong points, hence instructions need to be more on the detailed side.

I am all ears.

Many thanks, Michael.

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onondaga posted this 30 July 2013

The dimmer could be a switched transistor dimmer circuit that changes pulse rate of the AC. that would work if it is power rated 700 watts continuous. The dimmer could also be a variable resistance that changes voltage--that is not so good because as the voltage goes down the amperage goes up (OHM's Law) and the heating coil would likely be looking at more current than it is rated for. This would shorten coil life substantially; a 700 watt variable resistor is bigger than the box shown in the picture also..

Heating coils are inductive resistors and behave the same way as any resister does, when the voltage goes down, the current goes up (OHM's LAW) and the resistor takes a beating trying to dissipate more current. A current limiting circuit would assist in that area but those are not used in dimmers.

Switching transistors to handle 700 watts are expensive and require a substantial heat sink mounting. The light dimmer in the picture is for home lighting and not rated for anywhere close to 700 watts. It might last a while but its future is dubious.

A speed controller for power tools rated for 700 watts would be fine and handle the duty but it may not handle the surge current turning on the heating element. Harbor Freight has one that is inexpensive, but risky.

The standard thermostats that come in melting pots are just thermostats, they are a variable timing circuit that turns the heating element on at full power for time intervals set by the rotary dial. That is why you can hear or feel the hum when the thermostat switches the coil on and later hear the silence when it turns the coil off at the interval you set the pot at with the rotary dial . The rotary dial itself is a low wattage variable resistor in a timing circuit for the main contact switch for the coil.

An electric hot water tank thermostat does the same thing turning on and off the heating element at full power timed intervals that you set.

A discreet device called a thermistor can also be used for this function and that actually senses temperature, but very impractical for melting pots.

PID controllers do work very well and can be home built if you are accostomed to populating circuit boards with components. They are not a complex circuit, kits are available on the web too, just watch the wattage and duty rating and get one that fits and a temp probe that will work with the kit.

Gary

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Jeff Michel posted this 30 July 2013

The thermostat is likely a Bilbee B200.They are available but not from Lyman. You can fine them on ebay from time to time. They are in stock at the Bilbee website. Last time I checked they were 60.00.

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303PV posted this 30 July 2013

A thermostat is not a timing device. On the lee pot and on the hotplate I have a bimetal is used. It is a on off control. It senses the temp and then switches the power on and off. http://en.wikipedia.org/wiki/Thermostat I use an electronic on off control with a k-type thermocouple. http://www.enda.com.tr/ENG/Products/Urunler.aspx?UrunID=169 It is simple and works very well. A PID controller is much more sophisticated. I have bought one, but I did not use it. I still have to build the box. Ask Uncle Russ for more information on PID controllers. http://auberins.com/images/Manual/SYL-2362%20instruction%201.6.pdf

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Uncle Russ posted this 30 July 2013

MR. 303PV; Thank you.

Mr. Black and Blue; Please PM me and I will send you a BI-METALIC strip heat control for your pot for free. Just need your address if you are interested. I get them from pots I have changed to PID control but usually just leave them in to plug the hole. The couple I have now came from LEE pots but you should be able to retro fit it to the Lyman if the shaft is long enough. I don't remember.

Check your old element with an ohm meter, you will have continuity (good) or not (bad). Or as Pigslayer says, bypass the stat and go direct. The element will get hot, or not. Hook the wire from the cord to the stat to the wire leaving the stat to the element. Make sure it is unplugged until you are ready to test and then don't let the magic smoke out. The only way to see if the element is going 100% full rating is to use an amp meter. It should draw about six (6) amps for a 750watt element.

Once again. These temp controllers have no idea what temperature the melt is. The current flowing to the element heats a bi-metallic strip. This strip heats to a point where it warps (clicks) out of shape, like a KLIXON switch in your electric furnace, or electric wall heater, or range top. Same, same. Not hot water tanks. The further the control knob is rotated the greater pressure a cam puts on the bi-metallic strip making it have to heat hotter, hence the element runs longer, hence the lead gets hotter, before it warps and opens the circuit, then cools down, closes and starts the whole cycle again. I think what he hears are gremlins, AC gremlins, nasty little fellows. They make you tingle if you touch them!

Now that is the way it works in the whole world but apparently not on New York. But then look at all they do in New York, must be the air! My good man, sometimes silence is GOLDEN.

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NORMSUTTON posted this 30 July 2013

there is no lead in it , because its my spare now, but it still works, this the one I have used for the last 5 years and it was used when I bought it http://s56.photobucket.com/user/NORMSUTTON/media/bent%20bolt%2038/bench03.jpg.html>

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Sawfish posted this 19 September 2013

Jeff Michel wrote: The thermostat is likely a Bilbee B200.They are available but not from Lyman. You can fine them on ebay from time to time. They are in stock at the Bilbee website. Last time I checked they were 60.00.

Go back to the Santa option!

"A man can never have too much red wine, too many books, or too much ammunition." Rudyard Kipling

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Tom Acheson posted this 19 September 2013

Here is my Lyman after 26-years of good service.

I'll get it repaired to do alloying but I've been eyeing a new Magma Master pot and ordered one of those without the bottom pour feature. Holds 40-pounds.

Tom

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Uncle Russ posted this 22 September 2013

That's cool. A real, live thermostat not a bi-metalic wunder switch. Robert-Shaw may be another source of replacement. That pot looks to be worth repairing.

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