An idea for a scrap wood lead melter

I found an interesting web site called back yard metal casting, detailing how to build your own refractory and furnace for melting metals and making forgings at home. Interesting stuff. I have no interest in doing that myself, but some of their designs might be adaptable to lead melting and alloy mixing.

I'm thinking in particular of the inital melt of old wheelweights. I've never found a satisfactory way of doing this. Just tossing them in the electric pot is smoky, messy, and yields different alloys from mix to mix. Melting with a weed burner is fast and effective, but propane isn't cheap and I find it takes about 1/4 of a 20lb tank to melt 50 pounds of lead. Putting your melting pot in a roaring bonfire works just fine, but living in the city that isn't an option.

So the basic design they used for their metal melter- generally oil or propane fired- is to take 2 metal pipes or tubes, 1 about 2" in diameter smaller than the other, insert them sleeve like, cut holes in both, shove a pipe through for fuel/air delivery (usually using an old dishwasher blower) and fill the air space between with concrete or fire clay. This set up also has a refractory cement lid on it and uses a small crucible to melt no more than a few pounds of metal at a time.

I'm thinking for the easier to melt lead, it could be upscaled and simplified. Picture this.

Take 1 metal pipe about 2 feet in diameter. Cut a hole in it. Insert vent line similar to what is described above. A dishwasher blower would be perfect and I could probably get one from a junk yard cheap. A dryer blower would also work. Heck even a good hairdryer would probably be fine. If a thick piece of pipe can't be found, a double lined arrangement like the metal melters use with fairly think metal (like furnace pipe or those holiday popcorn tins) would be fine; but for lead, just packing it with dirt or sand in between would suffice.

Next, chop up some scrap wood so it fits into the inner pipe. Light it. As soon as it catches, turn on the blower. The air flow coming in from the bottom of the pipe would cause the wood to burn quickly and hot.

Set your pot with the lead to be melted inside, right over the fire. I'd probably suspend it on a chain from above using a sturdy support; or else make sure that other provisions are made so it won't tip as the fire burns down.

I have to think this arrangement would melt the lead FAST, and it would only cost some scrap wood that I already have lying around, plus a few bucks in pipes.

Not a great artist but the pencil sketch below illustrates the idea.

Should work just be careful not to get things to hot. Also have some sturdy way of getting pot out to pour lead out or dip it out.
You would be able to get the lead way to hot this way I think but if you use a good thermometer you should be able to contro the air flow and the temp. of the melt....Wes

Try and find an old Coleman white gas burning camp stove. In place of the white gas I just burn unleaded regular gas. I make a skirt out of aluminum foil to go around my melt pot with a little flare on the bottom to capture more of the heat from the burner. You really don't need a forced air furnace to melt lead. If you want to melt using wood I pretty sure a charcoal grill and some strategically placed foil will serve you fine.

Merry Christmas

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Originally Posted by flhroy

Try and find an old Coleman white gas burning camp stove. In place of the white gas I just burn unleaded regular gas. I make a skirt out of aluminum foil to go around my melt pot with a little flare on the bottom to capture more of the heat from the burner. You really don't need a forced air furnace to melt lead. If you want to melt using wood I pretty sure a charcoal grill and some strategically placed foil will serve you fine.

Merry Christmas

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I have a coleman stove. Takes forever. Lots of slushy deposits in the cold spots in the melt.

Charcoal grill using scrap wood has similar issues; again, a roaring bonfire is fine, but anything less I've had issue with.

I've been smelting on a turkey fryer for a year with one five gallon propane tank. I'm sure I'll run out someday but I can fill the tank for less than ten bucks.

I don't think that you would need forced air. You are talking about making a forge basically and lead melts so much easier. All you really need is air vents in the botom.

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Originally Posted by mpmarty

I've been smelting on a turkey fryer for a year with one five gallon propane tank. I'm sure I'll run out someday but I can fill the tank for less than ten bucks.

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Tempting; however turkey fryers cost money. This would only cost a few bucks at the local scrap yard if that.

Maybe if I found a used one at a flea market or yard sale I'd go that route.

Less than ten bucks though? I fill my gas grill about once a year and it usually costs $20! Wish I were where you are, propane here is pricey. :(

Jonk,

You are working to hard at this concept of using waste wood to smelt. The nice thing about using a wood fire is that lead melts within the temperatures easily attained by an open atmospherically burning fire, you will not need to force /blow the coals to melt. You can melt aluminum in wood coals easily.

take an old semi tractor brake drum or large pickup brake drum and build you some nice hot coals in it or just build a small fire and feed it to the right temp to get the melt. You can do the same thing with a couple of rocks/cinder blocks/bricks, etc to make a fire pit. You can use a grate to hold pot or set pot in coals. You can make a non forced air forge using charcoal and a brake drum, that is definitely hot enough to melt lead (and the pot it is in).

Generally holding pot above the coals will help keep the pot from getting red hot.

You could also build a bottom draft wood burner with out the forced air. think of a trash barrel with holes in the bottom. Those holes are there to help bring air into the burning mass.

Look up a zip stove for an updraft forced air back pack wood stove, you could scale it up

http://www.digitalmarketingusa.com/ZipStove.html

or look at the following web page about half way down for a home made version ( other cool info on this page also)

http://zenstoves.net/StoveChoices.htm

another thing you can try is find a pipe that you can turn into the flue and build the fire under it so the heat comes up the flue and around the pot with the fire at to bottom end of the flue. The fire will push air up the flue and draw air into the fire. Kind of like a jet eductor type burner, it creates its own pressure to force air in for burning. without control of air inflow to flame they bet very hot.

I have other ideas for you also, but the above should bet you started without having to create a blown burner.

I'd say you don't need the double-layer for the furnace walls, neither do you need fire clay insulation. Just a steel container with a grate a few inches off the bottom (expanded metal) so the air can get under the fire.

The reason the brass/copper/iron backyard casters use an insulated furnace is because they're directing the flame from a burner directly into the furnace at an angle, and the super-hot blast plays directly on the inner wall so it creates a vortex that spirals around the crucible on the way up. In fact, I don't think they use an inner layer of steel, just fire clay, as steel would be melted away. The combustion actually occurs within the burner, either with injected oil or propane, so it's a little different than a forge.

A good forge with forced induction and charcoal ought to work fine, especially for city-dwellers. I had an idea a while back for a lead smelter that used a 30# (the tall one) propane cylinder with the top cut off. A hole would be cut near the bottom and a 6"x2" pipe nipple welded on which would have a piece of aluminum flex hose attached (think automotive heat-riser tubing) to connect to a hair dryer. A piece of expanded metal would be welded in the bottom where the straight sides begin to round for the end to make a grate. Using 10" pipe or the end of a retired oxygen cylinder, a crucible would be made and brackets made inside the propane cylinder to support it, but still be able to remove the crucible by pulling it out the top. Obviously the crucible support would need to be very strong. The crucible would need to extend up exactly to the the point where it would touch the underside of the cut off end. The end that had been cut off to do all the work inside the cylinder would then have a hole cut in the top (where the valve bungs are) and be welded to the top edge of the crucible, giving it a mushroom collar. An exhaust stack would need to be run out the side of the propane cylinder just below the cut in the top, and a door would need to be cut and hinged to the side to allow access to the firebox/grate to add charcoal briquets. A bottom pour valve would be added, and a small pipe run from it through the tank wall and outside to make a spout which is always kept hot by the fire. After everything is checked out and working, the tank end could be welded back on creating a complete enclosure of the firebox and an open cauldron/crucible on top. This would preserve heat and keep direct heat away from the user, allowing it to exit via the stack, which would allow one to stand over the pot for fluxing/reducing/ladling if so desired. A lid could be fabricated from flat steel or whatever was handy for safety when smelting range scrap.

This setup could be made to work with a built-in propane ring burner, an external oil injector burner, a weed burner head, wood, charcoal, coal, etc. and would be fairly efficient, hopefully producing no more smoke than a good barbeque.

Gear

Yes, that will work. I have some fire brick saved from a chimney project and had intended to build a FB box and use scrap wood and cut up pallets and an old vacumn cleaner with reversed flow for a bellows.

Plenty of heat and outside work without smell and smoke should make a smelting concern. Maybe in the spring./beagle

You would be surprised at just how cheap a good high BTU turkey cooker burner with pot stand is this time of year. Folks get them and find it not to be their cup 'o tea. Got mine for a song and I have propane anyway. Melts 100# of alloy PDQ.

prs