PDA

View Full Version : Lee melting pot insulation



rtracy2001
11-04-2009, 01:15 AM
I picked up a lee melting pot in need of some TLC off flea-bay, and the white fibrous insulation is trashed. What is this stuff made of? Asbestos, Fiberglass? Lee doesn't sell it, and I think I will want something to keep the outside a little cooler. What can I substitute?

:groner:

hammerhead357
11-04-2009, 01:56 AM
Try ceramic blanket isulation. It is common but right now it is late and I can't think of the name of the stuff. Oh yes maybe Insulwool or something like that...Wes

NoZombies
11-04-2009, 02:12 AM
KAOWOOL is the brand I've used for everything from building melters to lining forges, it should to the trick

dragonrider
11-04-2009, 10:28 AM
It may also be called Rockwool.

lead-1
11-04-2009, 10:45 AM
How do you folks think muffler packing for motorcycles would hold up to this application? The packing for mufflers actually see flame and sparks so it may hold up to the heat also.

Edit, OK found the answer to my own question, Average temperature of the exhaust of a 2 stroke is 1000* with a peak of 1100-1150*.

Bill*
11-04-2009, 11:24 AM
Lead-1: That's hotter than any melt, but it will be in contact with an element that perhaps gets hotter than that. Anyone know how hot the element itself gets? Glowing like an electric range? Just wondering...don't know the answer myself.....Bill

TAWILDCATT
11-04-2009, 10:13 PM
the element should not get hotter than the pot.:coffee:

rtracy2001
11-04-2009, 10:20 PM
The element has to get hotter than the pot, by at least a little. I remember from my heat transfer class that in a real system, your heat source must be hotter than the item being heated. The only question is how much hotter than the melt will the element get? If the thermostat happens to fail, the element could get very very hot with nothing to turn it off. Sure would be nice if it didn't burst into flames before I notice the problem.


I found a few things in the MSC industrial catalog that might work (temps up to 2300F on some of them) I want to go over to the home depot this weekend and see what they have for like heat guard for sweating copper pipes. I also want to check out a couple of the furnace shops and see that gasket rope is rated to.

454PB
11-04-2009, 10:23 PM
Which Lee pot?

I have the 10 and 20 pound bottom draw pots, neither have any insulation.

RobS
11-04-2009, 10:27 PM
Neither do either of my Lee 10lbs or 20lbs pots

hammerhead357
11-04-2009, 11:22 PM
Yes Kaowool or Insulwool is the ticket. I use it for lining my gas forges and several other things. I think it is used by RCBS for insulation in their melting pots also....Wes

stubshaft
11-05-2009, 12:06 AM
Just rebuilt my 20lb Lee and checked my 10 lb Lee and no insulation either???

rtracy2001
11-05-2009, 12:58 AM
Which Lee pot?

I have the 10 and 20 pound bottom draw pots, neither have any insulation.

It is an older production pot (not the IV, just the 2" height for now :wink: )

Circuit Rider
11-05-2009, 10:16 AM
Is Kaowool or Insulwool available at Home Depot, possibly under another name? If not where might I find it? Circuit Rider:cbpour:

59sharps
11-05-2009, 01:28 PM
Have you called Lee. See if they will send it to you or they my take the pot and rebuild or replace it.

rtracy2001
11-05-2009, 08:47 PM
Have you called Lee. See if they will send it to you or they my take the pot and rebuild or replace it.

I didn't call them, but the insulation was not listed on their website under service parts. maybe the newer pots are different and don't have insulation? Wouldn't surprise me if the original insulation was asbestos.

clong
11-05-2009, 11:05 PM
Why not just use plain fiberglass insulation? It's melt point is over 2000* C.

rtracy2001
11-06-2009, 12:32 AM
Why not just use plain fiberglass insulation? It's melt point is over 2000* C.

Most standard fiberglass insulation starts to shrink, smoke, or otherwise break down at about 500F. It may not melt until 2KC, but it stops working right well below there.

McMaster Carr (www.mcmaster.com) list fiberglass paper insulation that is rated for use up to 1200F (http://www.mcmaster.com/#pipe-insulation/=4dntnq)

Looking at the prices however, i may just go without it for a while.

RT

sheepdog
11-06-2009, 11:31 AM
Clay? Cermanics have been used since the dawn of man to shield in heat.

Texasflyboy
11-06-2009, 12:22 PM
I've used Rock Wool Insulation for shielding my pots.

Rockwool on Google (http://www.google.com/#hl=en&source=hp&q=rockwool+insulation&aq=0s&aqi=g-s6g-m2g-ms1g-m1&oq=Rock+Wool+Ins&fp=129dd626db73ba5b)

lwknight
11-11-2009, 06:48 PM
Fiberglass may withstand 2000 degrees but the binding agent will break down and burn at 800 or so drgrees, leaving angel hair which is not that great insulation. The kaowool is ceramic fiber. Real nasty stuff to work with too. We insulators hate it. Another product is called Min-K Its a quilted blanket with fiberglass ecterior and ceramic filler. It will withstand 1200 degrees and has extremly high R-value for its 1/4-3/8 thickness.

Personally, I would not insulate the pot.

Matt3357
11-12-2009, 02:20 PM
I bought some of this stuff for a project I am working on. Should get it today. Looks to meet all of your criteria cept it might be a tad thick for your application.

http://www.mcmaster.com/#9328k41/=4h1qob

item # 9328k41

Just found out that while extremely cheap, it is semi rigid and my shipping cost was outrageous because of size. Would be better to find something softer and smaller. I hope it will still work.

Thanks,
Matt

rtracy2001
11-12-2009, 10:29 PM
Personally, I would not insulate the pot.

Why not?

It can only help by reducing the temperature on the outside of the pot lower, and the lead inside the pot hotter.

I can see why Lee might not put it in the newer pots (it cuts into profit), but it is original.

I put all of the old stuff I could back in for now, but the next time I take it apart I intend to put in some high temp rock-wool or something like that.

blikseme300
11-13-2009, 09:01 AM
I built myself a 75lb electric bottom pour pot. The initial tests were OK but the time to liquid state decreased substantially after I insulated it. I use a PID control for the temperature and could see the smaller change in the temperature swings after I insulated it as well.

I wrapped the pot in 3/4" kaowool and covered this with a sheet of 1/16" aluminum held in place with large pipe clamps. The bottom of the pot is also insulated with a layer of wool sandwiched to it using a disk of aluminum.

I always leave my pot full of freshly fluxed melt before power down. When I start a casting session it takes approx 1 hour for the pot to be temperature stable and ready for casting. Using 2 Lee 230grn .45 cal six-bangers alternately the temperature varies about 20*F only. I had no idea how productive an uninterrupted 2 hour casting session can be! The level of the pot does not go down enough for a refill so no stopping at all.

If anybody here needs some kaowool I have a few square feet spare. Contact me off-list. (I got mine from a local power plant for free. They use this stuff in bulk.)

Bliksem