Playing with Fire

[Falkenhorst]

Lately I've been messing around in my spare time building furnaces. At first I got these little hobby booklets that go into detail on how to make them just right, with fireclay refractory and stuff. Being somewhat of a hillbilly though I realized I didn't need most of that shit, and they were too small for me. I mow lawns for my job, which basically consists of me driving around with a trailer and all my tools and trimming and raking up lawn debris. My brother gets to drive the tractor. I also pick up whatever scrap metal I find while I'm on my way to my jobs all over my local area. That means I get alot of aluminum stuff like Grills, Lawnmowers, window frames, and stuff.

Now obviously pure aluminum is worth the most as scrap, but alot of times if you break up say a mower deck, or the engine, you can't get all the steel bolts and studs and crap out of there without investing so much time that it negates the value of the scrap. Obviously the solution is to melt it.

After alot of screwing around, I came up with a furnace that works. I took a 55 Gallon drum and torched a hole in it a few inches up from the bottom, as well as cut the top out. Into the hole I inserted a 3' length of heavy pipe about 4" diameter. Into the pipe I put the air pipe of a leaf blower. I filled up the drum with busted picket fence slats and other random wood debris and poured some kerosene in there. Once I had lit it up and got the fire going good I started the blower and throttled it up to a proper setting.

The barrel started burning with extreme nasty force, shooting fire out the top and radiating intense heat all around. I took a cast iron pot, which acted as a crucible, and hung it on a chain across a pipe laid over the top of the barrel so the pot could hang right down inside the fire. The pot was filled with broken up aluminum pieces from a Toro self propelled lawn mower. After maybe 15-20 minutes of feeding the fire with wood scraps and dumping in drain oil, which is people leave at the curb when they change it from their cars, I had the pot glowing with intense bright red heat and the aluminum had melted down.

I lifted the pot from the fire and used a spoon fixed on a length of pipe to skim out the accumulated crap that was floating in the metal, like hunks of charcoal and ash and dross. This left me with a pot of clean metal. Since I didn't have any muffin pans or ingot molds handy to pour it into I just set the pot aside and let it cool off and harden. The result was a dome shaped ingot of shiny aluminum weighing almost 2 lbs.

I didn't take any pictures or video of the first melt, but I plan on doing more, and if people are interested I will be happy to document it and post the pictures here.

[Dracofrost]

I'm interested in seeing pictures of this when you get time to do more.

[Enigma]

I'm planning to do some backyard melting\smelting too once I move to Ohio. I think the easiest to melt is aluminum, but I want to melt copper and smelt\melt gold.

[aerius]

You could also try using a giant Fresnel lens, give it some time and it should be able to melt a couple pounds of metal. Some guy at Burning Man was using one to melt ingots of lead which weighed several pounds so melting aluminum shouldn't be a problem.

[Falkenhorst]

Ok, tonight I lit off a violent fire and melted a decent amount of Aluminum and had my girlfriend take pictures of me doing it. I'll post again soon with the pictures.

[Falkenhorst]

Here you can see the materials I will be using. BBQ Grill Clamshells, an engineer hammer for breaking them into chips, and the leaf blower that will power the furnace.


Here is the setup of the furnace. The blower will pump air into the barrel through the heavy pipe. The air flow keeps the pipe cool even at full burn.


Here I have smashed one of the clamshells and packed the chips into the crucible.


Here I'm cutting up sections of wrecked picket fence to provide fuel for the furnace.


I packed the wood into the furnace.


I hung the crucible into the furnace before lighting it.


Here I am lighting up the furnace.


With the furnace lit, I'm starting the blower.


Letting the furnace get going good.


Feeding wood into the fire. With the air blast from the blower, the fire consumes alot of fuel.


Putting more fuel in the fire. I had to duck in and out like a boxer to avoid catching on fire.


After that I dumped drain oil into the fire for awhile, which made it burn with extreme intense heat as you can see in this photo here. At this point the fire was producing disgusting amounts of radiant heat, and if it had been darker out you could see the barrel itself glowing red.


By now the crucible is glowing red hot. I probed it with the long spoon, and found that the aluminum had become molten. It was covered with a layer of floating coals and ashes which don't seem to corrupt the metal at all, but form a layer over the top. I estimate the heat at this point was at least 1200 F or more, which is the melting point of Aluminum.


I turned off the blower and removed the crucible from the furnace, setting it on the ground.


The crucible was so hot when I set it down the random debris on the ground flamed up.


Here I am skimming the dross and accumulated coals and other junk off the top of the Aluminum, leaving only pure material.


Here, most of the dross is gone and the upper layer is starting to "freeze" over.


Here it is in it's final form, still molten but now cooling off and returning to it's solid state. I allowed the Aluminum to remain in the crucible during this phase rather than pour it into a mold.


The lump of ash and dross that was removed from the crucible. Some of the volume of the metal is always lost as impurities during a melt.


Here it's cooling off enough now I can hold my hand over it.


I dipped it in water to cool it so I could handle the ingot by hand, and dumped it out of the crucible.


And here is the finished ingot, weighing approximately 2-3 pounds. It's mostly pure except for some sooty shit on the bottom side which I think is cooking dregs still stuck in the pot.

Anyway that's all the pictures I have, and I look forward to questions and comments.