Lee bottom pour furnace question

[Dead Dog Jack]

I am new to casting and just bought a Lee 20# bottom pour furnace. The instructions that come with it say to leave about an inch of alloy in the pot at the end of each use. So, do I have to drain it down to an inch each time? Or can I leave it somewhat full?

[Daddyfixit]

First off, Welcolm to the form!
It doesn't matter. I leave mine near full more often then empty. I've had it for a LONG time with no ill effects!

[462]

A pot that has leftover lead in it will re-melt it faster than adding ingots to an empty pot. Empty it whenever you change alloys or want to clean it, otherwise leave it partially full/empty.

Just a guess, but Lee's advise may be a non-rusting, pre-emptive measure.

[Doby45]

I normally top mine off prior to shutting down for the day. I put my sprues back in and even an ingot or two to get the melt topped off and my pot looks great.

[onondaga]

I have discussed that specific point of the instructions with the Lee Technical Dept.

A full pot left to cool can cause a problem. When reheating a full pot of solid alloy, the alloy expands from heat and can lift the valve causing it to flow during the melt. The metal melts in the pot from the bottom up. A full pot that has started to melt and is fluid on the bottom can have the solid metal in the upper part of the pot expand and lift the valve open.

Leaving one inch in the pot is very useful for 2 reasons. The exposed bare pot can be sprayed with silicone spray per Lee instructions and the silicone will even penetrate under the one inch of alloy and protect the whole pot from rusting. Spraying the whole inner pot with silicone when the pot is cooled is a needed step to prolong the life of your pot and protect it from rusting.

The pot with only 1 inch of alloy will quickly melt for more metal to be added easily.

An ingot mold under the spout will catch drips and is also great to make ingots with if your pot is too full when done casting.

You are new to the pot. The most important instructions are about the valve rod and the flow screw. Make sure you understand the instructions and how those parts work. Rotating the valve frequently is important to maintain a good seal. the flow adjustment screw can easily be over adjusted and cause continuous flow. Keep a screw driver next to your pot during use for turning the valve rod and adjusting the flow as needed.

Gary

[LeeRoy]

I am somewhat of a newbe also. I have been given a small Lee bottom pour, a 10 lb. I believe. It had about 1/2 of a pot of lead left in it, for years. I have emptied it and cleaned it a little. You said to spray the pot with some silicone spray, after it cools with some lead in it.

The question is what kind of silicone spray do you use, is there a perfered brand ?

Thanks

LeeRoy

[Dead Dog Jack]

Thanks all for the info!




An ingot mold under the spout will catch drips and is also great to make ingots with if your pot is too full when done casting.


Good point, Gary. In fact, I've already got in the habit of storing the ingot mould right there. :D

[onondaga]

I have GUNK brand silicone spray that I got on sale. I don't think the pot will be brand fussy. I have also used WD40 the same way. These will evaporate and leave very little, but be a rust preventative. Just don't spray a hot pot-that is a fire hazard.

If you got your pot empty, that is a good time to wire brush it out if you have scale that can be removed. Then spray and wipe it out a couple of times . that will give it a good cleaning. You do not want loose rust that interferes with the valve operation.

Gary

[LeeRoy]

Thanks for the reply.

I keep WD-40 so I will empty my pot and use a wire brush on it, when go to put it away I will spray it .

Sorry about taking over your thread.

LeeRoy

[Fredx10sen]

I have discussed that specific point of the instructions with the Lee Technical Dept.

A full pot left to cool can cause a problem. When reheating a full pot of solid alloy, the alloy expands from heat and can lift the valve causing it to flow during the melt. The metal melts in the pot from the bottom up. A full pot that has started to melt and is fluid on the bottom can have the solid metal in the upper part of the pot expand and lift the valve open.

Leaving one inch in the pot is very useful for 2 reasons. The exposed bare pot can be sprayed with silicone spray per Lee instructions and the silicone will even penetrate under the one inch of alloy and protect the whole pod from rusting. Spraying the whole inner pot with silicone when the pot is cooled is a needed step to prolong the life of your pot and protect it from rusting.

The pot with only 1 inch of alloy will quickly melt for more metal to be added easily.

An ingot mold under the spout will catch drips and is also great to make ingots with if your pot is too full when done casting.

You are new to the pot. The most important instructions are about the valve rod and the flow screw. Make sure you understand the instructions and how those parts work. Rotating the valve frequently is important to maintain a good seal. the flow adjustment screw can easily be over adjusted and cause continuous flow. Keep a screw driver next to your pot during use for turning the valve rod and adjusting the flow as needed.

Gary

Exactly! I found out that you need to watch the pot as it heats up as well, TWICE! [smilie=b: I run a 10# and a 20# to refill it. Twice now that 20# der drained half the pot when I wasn't watching. :-(

[45-70 Ranger]

Well, shucks! My poor old 10# pot finnally quit pouring from the bottom after 25 years of service. It would only trickle and such. So, found a self-tapping screw that fit the inside of the spout opening and now I have gone back to using the old Lyman dipper I've had for 45 years! Actually I kinda like going a step bask as it gives me time to work on getting it just right....

Now, when it was working and if I left a few pounds of lead in there, it would drip a bit as it heated up. I agree that leaving a lot in there will make the pot drip during the warm up.

Happy casting guys and gals!

Wade

[Doby45]

I leave my pot full and it has never dripped. The whole concept of the bottom melting and the top being solid and everything dripping out is hilarious. Let’s say my pot is full and the bottom two inches melt to a nice liquid state. The top four inches are still solid and still solidly locked on to the valve rod. It isn’t going anywhere. If it was dirty or drippy when you turned it off, it will be dirty or drippy when you turn it back on. This is not black magic, it is a pot with liquid metal in it and it is either on or off.

Way too often we get off on these tangents that mysterious stuff happens that simply can not be explained, but that is not the case. If you are fearful that your pot will empty after you have gone inside to watch the last half of your game while it warms it, just put a pan big enough to hold the pot contents under the spout. Or better yet, just put a weight on top of the valve rod and be done with it.

[mold maker]

I don't mean to start a fuss, I'm just curious.
What are you laughing at Doby 45??
Don't you think the lead contracted when it cooled, or that it can't freeze fast to the pot or valve rod?
It also happened to me and there was no other explination. It wasn't trash in the valve. The valve was sealed when it cooled, and as soon as the lead turned loose of the pot or valve rod, it re-sealed.
I'm not saying that it lifted the valve rod, but when the lead expanded from heating the preasure had nowhere else to go. It should have stopped as soon as the preasure was releaved, but it drained till the top turned loose and sank to contact the melt, then it stopped.
BTW mine is a Lyman 20 lb pot, not a LEE. I also have 2 Lee drip-o-matics that very rarely drip.
Can you offer a better explination for what happened.
Again, I'm just asking.

[Doby45]

Maybe I am jaded because I have a weighted valve rod and therefore I never see this phenomenon. I have had mine for two years and yes it may dribble from time to time if I do not clean my alloy well, but I have never had it empty it's contents nor have I had to do anything to the interior of the pot itself. No offense taken and none intended mold maker.

[Spector]

I would think that if the bottom lead went molten while the top lead remained solid and locked onto the valve rod and sides of the pot that several things could happen.

First since molten lead has expanded it will need more space not to pressurize. If the containment area does not increase in size that molten lead will now be pressurized to some degree and trying to find somewhere to go to decrease that pressure.

A valve that did not leak while just under gravity pressure might leak if that pressure were increased.

Also it is possibe that the pressure could force the solid lead on top to rise up in the pot and lift the valve rod when the irght ratio of molten to solid lead is reached.

It is also true that a very clean valve will likely hold more pressure before leaking that a dirty valve.

The fact that the heating element wraps around the sides of my 10 pound pot I suspect the sides might go molten first with the rod still trapped by the rising island of solid lead.

At 64 my mental powers seem to be slipping at an ever increasing rate, but that's how my brain processes what has been said here.......Mike

[Doby45]

When my pot is full and cooled the block of lead is not attached to the walls at all. It appears to contract once it has cooled. I can slide a piece of paper down the side of my pots wall. I can not move my valve rod though, it is solidly frozen to the block of lead. I would assume this gap along the block would allow any need pressure to vent.

[onondaga]

Quote Doby45"I have had mine for two years and yes it may dribble from time to time "

You are fortunate you have only had the pot 2 years. Continuing to put weight on the valve will gall the valve and the valve seat and cause premature wear-out of the valve and seat. That will lead to worse leaking. This can be repaired after a thorough clean out and the use valve lapping compound and rotation of the valve to re-seat a good fit..

The design uses parts with engineered sizes and weights to be used according to directions.

My pot is well over 15 years old and following the instructions of frequently rotating the valve rod has maintained the valve in good working order with no weights. You have galled your valve and seat causing it to leak excessively. The weight will continue to worsen the galling of your valve and seat and shorten the useful life of your pot. Consider the valve lapping repair and not using a weight. This will restore your pot to normal life expectancy.

OH! Some users have reported cleaning their pot by abrasive blasting. Remove the valve assembly first and protect the seat with a marble sized plug of beeswax pushed into and over the seat to protect it from sand blasting or you will make it a lot worse. Then, after blasting, re-seat the valve with lapping compound and rotation.

Gary

[Doby45]

You have galled your valve and seat causing it to leak excessively. The weight will continue to worsen the galling of your valve and seat and shorten the useful life of your pot. Consider the valve lapping repair and not using a weight. This will restore your pot to normal life expectancy.

Where did you pull that deduction from? Mine will dribble a drop or two every second or third casting session, you would be hard pressed to call that excessive. How would you know my rod or seat is galled? I doubt seriously if the 3 fender washers on the handle will cause the pot to wear at a faster rate than normal. I lapped my rod and seat prior to it ever being used. You assume way too much.

[onondaga]

I'm trying to help you. Are you always this way? Physics is physics, the valve is not designed to have weight added to it. Sure the extra weight can stop a leak. I am pointing out to you there will be a reaction to your adding weight where the design does not support it in balance with the engineering of the parts. You have obviously made a choice and I disagree with you . So what. Now go ahead and spew some vitriol or perhaps some epithets if you are not capable of agreeing to disagree. Go ahead, I can take it.

It is likely you will have to eventually increase the weight on the valve pin as you continue to gall it and the valve seat more with the extra weight. I read one member uses a vise grip pliers locked onto the valve assembly for weight to stop leaking, I disagree with him also. What is next? A brick for more weight? And then complain to Lee that the pot is junk and the valve is a poor design?

Gary

[Doby45]

Always what way? It is ironic that you indicate that I am "always some way" simply because I disagree with you. Where is the "vitriol" that you are so gallantly absorbing? You are simply making a point that the Lee design is perfect as it is and that instructions should be followed to a tee. I simply state the opposite opinion that the design does have weaknesses and myself and many others have resolved those weaknesses. I like Lee products and load all my ammo on a Loadmaster along with Lee dies, powder measures and hand primers when needed.

Also, how is it you are 'helping" me? My Lee pot is in perfect operation and I am sure it will be for many years.

And you are absolutely right, I will agree 100% to disagree with you and we will be fine and the world will still turn on it's axis.

[onondaga]

Yes.

Gary

[CATS]

Doby45,

How did you lap the valve and what grade of grit did you use?

Thanks!
CATS

[Doby45]

I used a thick paste of Comet and applied that to the valve seat and the tip of the valve rod. I then took an electric drill with a flat blade bit and went to town. It only took about a minute and I have ZERO problems with my pot. The occasional drip will happen if I put in an ingot that maybe was not fluxed enough but the fix is as simple as turning the valve rod a turn or two.

[RugerSP101]

I am new to casting and just bought a Lee 20# bottom pour furnace. The instructions that come with it say to leave about an inch of alloy in the pot at the end of each use. So, do I have to drain it down to an inch each time? Or can I leave it somewhat full?
I found out the hard way you dont want to let the pot go empty. Especially if youre using something like wheel weights. Crud all over everything and all the way through. Had a hell of a time cleaning it up.
Now I just make sure Im about 1/3 full.

[ph4570]

My lee pot is ancient. I always top it off at the end of a casting session. I cast about 100# a month. The pot works now just as it did new. I have never completely emptied it and cleaned it. I have nearly emptied it when changing alloy.