Lead Smelting Pot

[CollinLeon]

I was thinking about designs for a lead smelting pot today and doing a bit of reading in the archives on this site. It seems that there are basically two different approaches:

1. Cast iron or steel pot with a ladle to fill the ingots (which is what I'm using now).
2. Bottom pour pot.

After thinking about it a bit, I remembered what the various foundries used for metals -- a top pour pot that is mounted on some sort of swivel / single-axis-gimbal...

Something like this:
http://www.terminalbrassandaluminum.com/*site/scaled-images/web/images/home-jpg-446x304.jpg
http://us.123rf.com/400wm/400/400/paulfleet/paulfleet0909/paulfleet090900011/5474742-illustration-of-molten-metal-being-poured-from-a-foundry-crucible.jpg

http://us.123rf.com/400wm/400/400/paulfleet/paulfleet0909/paulfleet090900011/5474742-illustration-of-molten-metal-being-poured-from-a-foundry-crucible.jpg

I figure that such a thing could be accomplished for a smelting pot by welding a pair of steel rods on either each side of the smelting pot or maybe a steel rod going all the way through the melting pot such that it was balanced a bit and thus not so difficult to tilt. A lever could also be welded to it so as to give more control during the tilting action. The foundry examples that I've seen don't seem to have the pivot point that low and rely on some sort of winch / block and tackle to lift the bottom of the pot to start it pouring. Their pots have some sort of pour spout in them. I would think that you could weld a small top over 1/3rd or so of the top of the pot so that you could tilt it far enough that you were not just getting the top skim off the lead during the pour...

Has anyone around here tried such a solution? The main advantage that I see is that it would eliminate the possibility of a leaky bottom pour while also making it so that someone with just a basic welder could fabricate the project. Many of us either don't have the space in our garages or cannot justify the expense (due to the fact that we think that we don't have any other uses for it) for a metal lathe or drill press.

You could maybe even install a piece of pipe from the bottom to the top so that it would be like one of the Rowell casting ladles...

http://ecx.images-amazon.com/images/I/41xD-VDBeYL.jpg

I looked around through the archives, but didn't see where anyone was using such a solution. I find it difficult to believe that I've come up with a unique solution, so there must be something wrong with my idea... Please enlighten me...

[D Crockett]

first of all your link does not work if it looks like what I think you are asking you will be asking for trouble if a weild should break and they do break you could be heading to the hospital or the undertaker my advise would be do it the way the rest of us do it with the pot of lead sitting still and ladel your ingots out it is safer that way D Crockett

[CollinLeon]

first of all your link does not work if it looks like what I think you are asking you will be asking for trouble if a weild should break and they do break you could be heading to the hospital or the undertaker my advise would be do it the way the rest of us do it with the pot of lead sitting still and ladel your ingots out it is safer that way D Crockett

I think I've fixed the link...

The weld breaking would be a problem with any pot that you welded up yourself unless you start out with a piece of pipe that had a humongous cap screwed on the bottom instead of a flat plate... There would be more weight on a smaller welded area, so it would be more of a concern than on the bottom... Neither is a problem if you have someone do the welding who really knows what they are doing with a welder... :)

Now, converting an old steel-72 SCUBA tank into a smelting pot might be an interesting idea since there is no welding on the bottom or the sides... They are dirt cheap if you can find one that does not pass hydro anymore...

[CollinLeon]

Just for curiosity, I just called one of the local SCUBA shops and the guy said that he would actually *give* me an old steel-72 cylinder that had not passed hydro. They're a little narrow for a large smelting pot, but there is a possibility that the bottom 12" or so would make for a good gas fired casting pot...

[1hole]

Had to give up SCUBA but still have a half dozen steel 72s I plan to do just that with.

Gonna use the bottoms for pots and will make a charcoal burning up-facing blast furnace with the tops. Will blow air through the bottom valve openings with a small fan. Figger I can cheaply and safely draw down 30-40# of metal per melt and thats enough for me! I have about 150# of wheel weights and at least 300# of pure lead plus some 60/40 solder waiting for processing into 1# ingots.

[shadowcaster]

first of all your link does not work if it looks like what I think you are asking you will be asking for trouble if a weild should break and they do break you could be heading to the hospital or the undertaker my advise would be do it the way the rest of us do it with the pot of lead sitting still and ladel your ingots out it is safer that way D Crockett

I totally agree with the safety issues that are said by D Crockett. Better yet than ladling is to built a simple yet affective bottom pour pot that will not leak. I am very pleased with the one that I built with only a minimal amount invested. Take a look and see what you think... I'd be happy to answer any questions you have about it.

Shad

http://castboolits.gunloads.com/showthread.php?t=146065

[meshugunner]

I have a small blacksmith shop and do some welding too. I tend to take more risks than most other people but I wouldn't go near this! It's a cool but very bad idea. Having a tiltable pot of molten lead is a setup for a horrible accident! By the standard method of bullet casting you could get a nasty burn or two, even some eye damage but you would have to be very drunk to suffer the kind injury that this setup could produce. 20 - 40 - 80 lbs of 600 deg molten lead in free fall could probably kill anything on this planet. If it finds it's way into your boot the best you can hope for is that you will lose the foot. You might well go into shock and not even be able to call for help. Metal casters working with crucibles of this design work as a crew with full body protective cover. Even then the accidents can be awful.

Then there are the construction issues that people have mentioned. It is very difficult to weld cast iron. I tends to just crack. Experts do it and even then it's iffy. Nor can you heat it and form it to make a pouring spout.

I have seen threads where people have taken heavy gauge sheet steel rolled it up and welded up a melting pot. That should work fine if competently done. Mild steel welds easily and reliably and even if a weld cracked it wouldnt lead to a catastrophic failure, perhaps some leaking. But these were all standing pots.

Notice that these crucibles all have their pivot points close to their center of gravity. This is so that it is easy to tilt and pour a heavy charge. And there it is. The design is inherently unstable. It has to be to work well.

I wouldn't even cook soup this way :)

[CollinLeon]

I'm talking about using steel pipe to make the pot, not cast iron, so the welding is a lot easier... It would be easy enough to make it so that there was no danger of the pivot points breaking off from an improper weld... All you would need to do is run the rod all the way through the pot about an inch below the top of the pot... I also proposed putting a 1/3rd top on the portion of the pot where the pouring is to be performed and having the spout come out at the point between the top and the side... The spout could be made from smaller diameter pipe to minimize the amount of lead that can flow at any one time...

[meshugunner]

Steel pipe would be a good stock to work with. Can you find it? Most large diameter 'iron' pipe is cast iron. The main exception is tubing made for structural members. It tends to be rectangular but that might work too. It might be easier to get a piece of sheet metal rolled up. Yes you could penetrate it with a piece of pipe for a spigot. You would have to think about the lead freezing and solidifying.

What kind of charge do you have in mind? If this is to be a heavy load, you may find it very awkward to pour unless the pivot point is close to the center of gravity in which case you have a tippy vessel full of molten metal. I also think you will have difficulty controlling the flow at the top and it will tend to spill over unless you add a partial cover. Even with the pivot point fairly high, the crucible can swing and splash. Crucibles are usually not used for pouring small quantities under fine control. Rather a large charge is dumped quickly into a big mold.

[afish4570]

This is what I use. They are easy enough to find and make. You could experiment using heavy bolts drilled thru pot instead of trusting your welds. Steel loops or plates could be used to make the pivot points to connect the lifting hardware....... I am pleased to dip my 150# smelt and to pour it would be more fuss and danger for the few times a year I would do it. But just giving you a few ideas. :Fire::Fire:afish4570

[Longwood]

I'm talking about using steel pipe to make the pot, not cast iron, so the welding is a lot easier... It would be easy enough to make it so that there was no danger of the pivot points breaking off from an improper weld... All you would need to do is run the rod all the way through the pot about an inch below the top of the pot... I also proposed putting a 1/3rd top on the portion of the pot where the pouring is to be performed and having the spout come out at the point between the top and the side... The spout could be made from smaller diameter pipe to minimize the amount of lead that can flow at any one time...

Go for it.
It is pretty obvious that you know your ability much better than people that don't know enough to pull it off.
I need to finish the one I started just to prove to everyone that says it is dangerous, just how mistaken they are.
Problem is, I don't need it, and have more important projects going.

[Edit]

Here is a photo of a tank that I cut and made a short lip for, with a piece of the top I cut off, so I could stand behind it while smelting reclaimed lead.. It is only tacked in place right now.
I cut the tank with a die grinder after I was told that it would kill me by someone that had never done it.
After looking at all the trouble I was going through for the bottom pour spout, (I wanted it to be flat and even with the bottom of the round bottom of the pot, so that took a bit of fabricating) I decided to try doing similar to what I has seen done thousands of times in a nickle smelter in Riddle Oregon.

Like I said, I don't really need it, so right now it just takes up too much room on my welding bench.
I posted this photo a few months ago telling my intentions of making a tilt pour pot, and a bunch of people that had never made one told me it would not work without even knowing how I intended to build it. ??????

The weather has been pretty hot but if I start early in the mornings, I can finish the pour feature pretty quickly, so maybe I will and post a video of how simple and well it works.

[CollinLeon]

You could experiment using heavy bolts drilled thru pot instead of trusting your welds.

That might be an interesting solution to the side stud issue without having to just do a butt joint weld of the side studs to the sides of the pipe. I figure with a 5/8" bolt on each side and welded around the perimeter of the inside hex head and the outside round shaft, it would be plenty strong for a medium size smelting pot... I don't have the supply of wheel weights that some of you do that would cause me to need a really large smelting pot.

I'm currently using a 8 qt cast iron dutch oven for a smelting pot. If it was filled all the way, that would mean 189 lbs (assuming 0.4092 lbs per cu-in). I normally do not allow the lead level to get past 2/3rds high, so that means 126 lbs in a batch.
http://lh4.googleusercontent.com/public/JCUF5oQUtR4ufpVy1MrZGzJO9HeCOieuk20_kpRHf2kRG95orE 6kdI7by-qGprQEdZuFoTTwUWdblvkvnfKufDFiR2KzrCoVhlGT04BAG7Uy x-66th2NwtJuVaV0oHUalsEwDEKsJLc5ap2HjfWiLN9cZPJ4nMdL FUIeZZwHBi5rrb1JEij3qw

The piece of pipe I picked up at the scrap yard the other day is 8-1/2" tall and 7-1/8" ID with a 1/2" wall thickness. That works out to be only 107.88 cu-in and 44.14 lbs if fully loaded. Being taller, it could safely be run at at 3/4 level, so we're only talking about 33 lbs there. As such, it would probably be more appropriate for either smaller smelting jobs or as a casting pot. Either way, it's probably a good candidate as a bottom pour pot...

As I was thinking about what to do with the pipe, it just occurred to me that all the smelting pots in the commercial foundries are top pour with a spigot and not bottom pour, but you never see any of the bullet casters proposing such a thing, so I was curious why it was that way...

Now, a steel-72 SCUBA tank is about 0.425 cu-ft in volume -- let's call it 0.4 cu-ft after you cut it off at the bottle neck below the valve, so 691.2 cu-in which works out to a potential for 282.8 lbs. That shows a bit more potential, but it might be too narrow and waste a bit of heat...

I'm mainly thinking that a smelting pot that is a bit taller and not as wide would result in less of the surface area of the pot being exposed to air and oxidizing, thus less dross formed...

[CollinLeon]

Steel pipe would be a good stock to work with. Can you find it?

Finding it would be no problem... I have seen up to 30" or so diameter steel pipe pieces that were 1" or more in wall thickness in the scrap pipe section... I have seen pieces of steel plate that were up to 4" thick there also...



What kind of charge do you have in mind? If this is to be a heavy load, you may find it very awkward to pour unless the pivot point is close to the center of gravity in which case you have a tippy vessel full of molten metal. I also think you will have difficulty controlling the flow at the top and it will tend to spill over unless you add a partial cover. Even with the pivot point fairly high, the crucible can swing and splash. Crucibles are usually not used for pouring small quantities under fine control. Rather a large charge is dumped quickly into a big mold.

For a really heavy load, I would use some sort of cable attached to a lip off the bottom of the pot to lift it slowly. I would probably make a sort of hand winch out of a piece of pipe with the cable wrapping around it with a larger wheel on one end for turning it. Kind of like what you used to see for manual boat lifts...

For the load that I'm thinking, just providing an extension lever welded to the side of the pot would probably give me enough leverage to tilt the pot and would allow a fine enough level of control to reduce the chance that I might spill it. I'm thinking that piece of pipe with maybe a 1/4" ID would provide a small enough opening that I would not have an excessive flow rate. The ingots that I produce are small enough in cross section to fit in the Lee 20 lb pot, but they are long enough that they do stick out a bit until they melt down some...