My Smelting Furnace

[RoGrrr]

I was getting tired of manhandling the 3 quart cast iron pot over the turkey fryer so I decided to build something larger, along the lines of what others have built. I wanted something that was safer. The pot weighed about 20 Lbs and I had to support the free end with a pair of channel locks. There was a very real danger dropping the pot and/or spilling the melt. After doing a couple hundred Lbs of ingots I was getting scared of those odds. The new furnace is a whole lot safer.
I went to the scrap yard and I bought a piece of 7x9" pipe and squared up the ends on my milling machine. Then I welded a bottom onto it. After I built the stand I realized it would be quite inefficient so I added a chimney around it to channel the heat up around the vessel and off to the smelting races I went. I realized I needed a bigger ingot mold so I copied some of what I've seen here, too.

Cleaning the ore is a 2 part operation done with a garden hose and sprayer in my tilt bed trailer. I spread the ore and wash with the hose, getting most of the mud out. Then I have to sort the sticks, stones and shotgun wads out. With half ton of ore to smelt, this is no small task. I tried to my air hose but that wasn't too successful. I then set up a furnace blower and dumped handfuls of ore into the air stream. This blew plenty of the crep away. Some of the heavier crep needs to be removed by hand but it's still better than doing it all manually.
I can't post my vid of the air-cleaning process to imgur. It's 88Megs !

From there I smelt in my furnace. Originally, I was using cornbread muffin molds but at just over a pound each, I decided to go bigger so I built a new set of molds out of angle iron. The new molds yield 3 pound ingots which stack better then the half-round ingots.

I found I would not be able to hold the mold steady while filling with melt so I built a trolley to roll it along. From there I dump the mold into a pan of water to speed up the cooling. As the mold is drying, I add more ore to the furnace. Then I fini the drying process with my air hose and pour more ingots.

[RoGrrr]

More Pics
Flame
The chimney
View from top
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[RoGrrr]

More
View from front
Trolley
Side view of trolley
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[RoGrrr]

More
Details of trolley with guide to keep mold in line with rollers
Ingot mold views
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[RoGrrr]

Cooling,
Cooled,
Finished ingots
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[Jim]

For the sake of your safety, I hope I'm wrong. I think you're going to be in for quite a surprise if/when you slide one of those water cooled ingots into a half empty pot of molten alloy.

If you've done it before with no ill effect, you're all set. If you've never dropped a water cooled ingot in a pot of molten alloy, be ready.

[Geppetto]

For the sake of your safety, I hope I'm wrong. I think you're going to be in for quite a surprise if/when you slide one of those water cooled ingots into a half empty pot of molten alloy.

If you've done it before with no ill effect, you're all set. If you've never dropped a water cooled ingot in a pot of molten alloy, be ready.

Jim, could you expound on your statement? Being a newbie, a description of what you expect could happen would be very useful, rather than alluding to some sort of catastrophe.

[RoGrrr]

Jim
Not sure what you're getting at but when I start casting and put an ingot into the Bullet Master (I should call it Boolit Master but it's a tm with Magma) the ingot WILL be dry.
I do get PLENTY of steam when I immerse the mold into the pan of water. The first time was quite surprising but it's relatively safe.

[Sweetpea]

Very simple.

Water trapped inside lead equals a visit from the tinsel fairy.

Brandon

[RoGrrr]

How is water going to get trapped inside ? The ingot is not porous from the pour. I doubt I will have a problem.

[Spawn-Inc]

I melt my 4lb ingots that are water cooled with a torch over my 10lb pot and they will start spewing little bits of molten lead. I think water gets sucked into the ingots during the cooling process. So as stated, be mindful when adding them to molten lead.

[RoGrrr]

Spawn, Sweetpea and Gepetto
Here is a pic of one of my ingots and at first, I thought you were full of it. However, as shown, you DO have a point that I'd never thought of. There IS a minute possibility of moisture hiding in one of those "folds". I will be careful when I insert the ingot. Having learned about the tinsel fairy, I will place a copper screen over the furnace on the bullet master so if there is any bubbling/splashing/eruption it will be contained.
THANKS for your advice !

67567

[JonB_in_Glencoe]

I would advise against liquid-water cooling ingots.

I use a water soaked towel to cool the filled ingot mold.

Keep the ingots dry. it only takes the smallest drop of water to create a fairly good explosion in molten lead, it's not neccessarily gonna just sizzle or bubble. the drop of water expands and turns to steam as quick as a 357 Mag and all the lead above that explosion is gonna FLY.
Good Luck,
Jon

[Spawn-Inc]

Luckily when it's happened to me its only ever been little bits of lead splatter. You can hear the hissing from the water boiling off. My ingots looked like a solid block so I'm not sure how it gets into the block. The only thing I can think of is the fact that it shrinks during the cooling process and somehow sucks it in.

[RoGrrr]

Jon
The towel is ok for boolits but my mold is about a foot long and each ingot weighs 3 Lbs (15 Lbs of lead plus about 5 Lbs for the mold) so I use the bath. The ingots sit for days before getting used so I'm not scared. Besides, the copper screen will contain any explosions.

[JonB_in_Glencoe]

RoGrr,
I did forget to say, that is an impressive smelter setup ! I am jealous.
I'm glad you're not scared, I hope you're right about the screen,
Good Luck,
Jon

[John Allen]

The smelter looks great. Have you thought about putting two the high velocity fans that have the square outputs on the mold. This should cool it pretty quickly without the worry of water.

[RoGrrr]

RoGrr,
I did forget to say, that is an impressive smelter setup ! I am jealous.
I'm glad you're not scared, I hope you're right about the screen,
Good Luck,
Jon

Jon
When I was smelting the other day I laid in some dampish ore and when it started to boil/crackle/splatter, I grabbed a piece of screen and slapped it over the pot. It kept splattering but the screen caught it all. I guess I could have used aluminum screen but I had just made a copper screen shield for my sand blast cabinet window. That's what I had handy and it worked well.

I got some ideas from kenjuudo, shadowcaster and several others around the net. As I was building, different things told me "this won't work" so I had to change my plans. Initially, I started with a smaller burner but found this bigger one in the pic so I went with it.
My thoughts now are to build a midget sister to this one which is shorter. I dump in ore and I find it a bit hard to fish out the jackets and dross. Here: http://castboolits.gunloads.com/showthread.php?t=707 Shadowcaster shows a wide but shallow furnace. Initially I didn't like his but I've changed my mind and will lean towards something like it for GEN II. I'll add a chimney tho, and a plenum to direct some of the heat around the nozzle to insure it doesn't freeze up. Once I got mine really up to temp, I didn't have freeze ups.
I like Kenjuudo's valve better than Shad's. I'd seen a threaded valve setup that almost burned the caster's hand when his spout froze.
It's a learning experience with plenty of evolution. Not sure what I'm going to do with this one when I build GEN II, tho. I might use the stand, since I bolted the pot into it. Well, actually, if you look closely, third pic of post #2 (img 0800) you might see how I built the stand around the pot. The pot is bolted to an angle iron on its side. You'll note in the top views that there are some bolts around the rim of the pot which seem to do nothing. They are screwed into nuts welded to the square pipe. I welded them on in order to hold the pipe down so I could mill the end of the pipe square/true. Flipped it over and squared up the other end. Then I bolted it into the stand rather than welding it all together. So now I can simply unbolt/remove the pot and either sell it or use it for something else and not have to build another stand, which would necessitate finding another burner. I built this stand freehand which was no easy task, considering how heavy the pot itself is, something like 25 Lbs. I had to suspend it in position with a chain hoist so I could tack things together. Now it's sturdy enough that it will hold a full load of smelt and I don't have to worry about it breaking or warping.

[RoGrrr]

The smelter looks great. Have you thought about putting two the high velocity fans that have the square outputs on the mold. This should cool it pretty quickly without the worry of water.

John
I could do that but maybe it would spray some of the melt. I'll look around for another blower in this particular configuration and try it. I'll check with a furnace contractor to see what they remove when they do a retrofit.
Also, blowers like this are great for creating a breeze in your garage, Patio, basement, etc.... in the summer.
The other thing to consider is how the air would affect the burner. I smelt in an open garage rather than outside to avoid a wind-whipped flame. If I installed more skirting/chimney, your idea might work. It has merit.
This is what I like about posting in forums. We swap ideas and modify what we design.


EDIT
John
Initially, I thought you meant directing the airstream over the melt as I'm filling the molds. What I do now is to wait until the last ingot poured has cooled enough so that it has just 'skinned' over and dump it into the water. If I build another set of molds, I could simply set one on the floor and wait for it to cool a little more than now and be able to dump the ingots out without watering them. Great idea. Thanks.

[km101]

Great setup! You have obviously given this a lot of thought. And you seem pretty good a fabricating what you need! I don't need the size that you have, but I wish I did. Happy Smelting!

[Sweetpea]

I'm thinking about two more mold blocks would be about right...

[shadowcaster]

I like Kenjuudo's valve better than Shad's. I'd seen a threaded valve setup that almost burned the caster's hand when his spout froze.

Just as information.. I have never had the spout freeze up on my smelter nor will it because of the redirection of heat against the spout. It is designed to flow freely with no freeze ups. Also, my handle sits high enough above and at the front of the smelter so that you could (not that I would) use a regular leather glove to open and close the spout without getting burned. It's super efficient and a pleasure to use.

It's always nice to see another bottom pour smelter join the ranks! :-)

Shad

[Racenviper]

Besides, the copper screen will contain any explosions.

Did you buy the copper screen local? What was the mesh size. I'm interested in a photo of this screen you made for your pot. How is it attached to the pot?

[RoGrrr]

Here's the furnace blower I use to sort my ore. The vids show the results of what it does.
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I posted a couple of vids to youtube.

AIR SORTING/CLEANING RANGE SCRAP
All the slugs drop into the first pan. Even large shotgun wads get sorted by the air. Most of the twigs, stones and loose copper jackets get blown into the second row of pans.
http://youtu.be/Zm07NSxyMwQ

POURING INGOTS
http://youtu.be/G9hMJaDyURs

These stainless steel pans are what you see at restaurants, especially on their salad bars. I find them at scrap yards for about $1 per pound. Each one weighs about 2 pounds and are a fantastic value. They are 13" X 20". The deep ones (about 6 inches) shown hold about 200 pounds of cleaned slugs.
I buy all I find since they come in handy for lots of things. I keep one in the trunk of my car for holding odds and ends. I throw my empty brass in them.