Instructables
Here I'll show you how to make a furnace for melting aluminum. The materials can be bought from Wal-Mart and your local hardware store. Cost to build furnace alone: $23 Cost of furnace and materials + tools to operate it: $50

*** 5/31/09 *** I will be making a new, revised charcoal foundry instructable as soon as I get some spare money. This setup is adequate, but there's always room for improvement.
 
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Step 1: Materials and Tools

Picture of Materials and Tools
Required to build furnace...
-One normal sized coffee can (6")
-One hair dryer with a cool mode and preferably two speeds
-Duct Tape
-One 1.5" x 10" galvanized/black iron pipe nipple
-One soup can
-Tin snips

Required to operate furnace...
-Long tongs or pliers to grip crucible
-Steel spoon w/ holes in it
-Heavy leather work gloves
-Lighter Fluid
-Charcoal
-Lighter

Step 4: The Crucible

Our crucible here is simply a tin/steel soup can. They're cheap/free, they melt at a higher temperature than aluminum, but they're one time use. Don't attempt to use it twice or it will melt through spilling your precious aluminum on your furnace.
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sconner111 months ago
One could always sand or grind the zinc galvanizing off of the pipe nipple if you are worried about fumes.
I admit, Sometimes I weld galvanized parts together and can vouch that it is smelly and toxic.
Dust masks won't help.
It's better to not create the fumes in the first place, than to try not to breathe them.
sconner1 sconner111 months ago
Grinding the inside of even a short length of pipe poses a problem.
Looking harder or *Gasp* Asking for assistance finding the black pipe nipples may be the easiest fix. Or use copper which has an even higher melting point than steel.
Welders use copper "spoons" to back welds that are at risk of burning through.
Ahnassi1 year ago
how much time the air blower will work before it overheats itself. is it enough to melt aluminium?
patlicky2 years ago
can i use barbewue heatbeads or barbeque fuel instead of charcoal?
just buy a bag of charcoal, its not very expensive and it is just alot easyer.. or you could just make your own: http://www.instructables.com/id/How-to-Make-some-Charcoal/
babeh20113 years ago
Can I replace a soup can with a ceramic cup? Because as I know, ceramic can stand in extreme high temperature.
you will need make sure that the cup has no air pockets in it otherwise it will explode...
fragmaster44 years ago
Just a safety precaution, Aluminum gives off harmful vapors when melted; Wear some kinda mask at the least.
Not really. Anyway they're much less harmful than the other vapors the whole process will be producing, so you really should only worry about that if you have fixed all the other odor problems first.
Unfortunately, fragmaster4 is right, but "some kinda mask" won't help significantly since those vapors will be heavy on ionized aluminum, unhindered by regular anti-dust masks.
flatcurve5 years ago
The slag is just the paint and PVC lining from the can (and crucible). Aluminum used in soda cans is actually very pure
could you just sand the label off to reduce the "slag"?
the Aluminum in cans is very pure (though i'd believe that some oxidizes to slag as well)

BUT there are 3 very pure alloys: for the body, the top and the tab
each, separately, is high quality alloy- but melted together they make a much less useful metal

all those "recycled" aluminum cans we gather are actually "downcycled' in the worst sense of the word
-but with enough patience (or teamwork) you could take the tabs and tops separately, and use them for bicycles, airplanes and anything else aluminum your heart desires
I agree but you dont get very much for one can and it is easier to find scrap aluminum.
patlicky2 years ago
does this actually work?
patlicky2 years ago
does this actually work because i have tried alot of ways to make a furnace but none of those ways actually worked. So my question is does this awesome furnace actually work before i make it? Please reply :)
josh13243 years ago
Can you just line the walls of the furnace (on the inside) with mud/clay to make the can last longer?
mud would harden then flake eventully smothering the fire in dirt. clay could work however there is a chance of it cracking aprt. so be careful
Wiredfey2 years ago
Question, it's mentioned you use duct tape to hold the pipe on.anyone know if i'd be able to solder the pipe straight onto the hair dryer??
curvy772 years ago
thank you for your instructable! while i did not make the one u did it inspired me to begin my own forge. for mine was made of brick (not the BEST choice i admit but whatever) but i used your view in a small contained forge.
the pro6 years ago
i don't know much about metal works but so why do you need the forced air?
n0ukf the pro6 years ago
The forced air increases the heat of the fire, a forced draft rather than natural draft gives more combustion air to the fire. This is part of the same reason blacksmiths have blowers on their forges. As the coal cooks down to coke, it needs that draft air just to stay burning.
u mean the oxygen?
Yes, the oxygen is what makes it burn, but air is about 78% nitrogen and only 21% oxygen.
if someone here came up with a way to make pure oxygen, please make an instructable on it. It will help w/ the smelter ( can it melt iron by blasting pure O2 into the fire ? )
easiest way is to use hydrogen peroxide from the chemist (you use it to bleach your hair) and then add chopped liver as a catalyst to produce a lot of O2. the higher the vols the more gas produced. If my basic school chemistry is not in error!
2k4u (author)  strangebike5 years ago
While meat and H2O2 will produce some oxygen, it's a very small amount. I saw that experiment in a science fair book. It would never produce enough O2 to fill a balloon, much less help a fire. Common drug store hydrogen peroxide is a mere 3%, which is pretty bad for most experiments...If you have a barber/beauty license, you can get around 10% for bleaching hair...if you find the right chemical supplier, you can get gallons of 20% - 35% for cheap. One of the best chemical ways of making O2 is decomposition of H2O2 by adding MNO2, manganese dioxide. If you can't buy some from a chemical supplier, you can take it out of zinc-carbon battery. But for hobby scale metal melting, you don't need any oxygen. It would likely get too hot and burn up whatever your foundry is made of.
hard2bme 2k4u3 years ago
where do you put the zinc carbon?
right into the fire where the charcoal is?
You don't need a beauty license to buy it. I have my cosmetology license but have never needed it to buy anything, and a barber, well they aren't allowed to do any chemical services with their license anyway. A beauty supply store not affiliated with a salon would be your best bet to pick up a lot for cheap.
yeah I knew there was a another chemical based way but couldn't remember it. thank you for jogging my memory. You are probably right lots of oxygen is going to make one hell of a pool of slag on the floor lol he he
wonder how you'll clean up the mess before it puts a black spot on the ground, haha:))
just wondering if I can use this on ceramic foundries.
Pure O2 is very dangerous. Blacksmith forges use forced air (not pure O2) all the time to soften iron for working into the desired shapes. If you leave it in the forced-air fire too long, it starts melting/burning away. Just before you get to that point, the iron is just soft enough for forge welding.
collard41 n0ukf6 years ago
if you use it on cold setting the air is denser, and therefore you can get more airin the furnace at once and it will burn MUCH hotter
Can u use wood vs coal?! plz respond asap
is there a hole in the bottom of the coffee can? it kinda looks like it and can this be build underground like in a sand environment?
KyleHarima4 years ago
I would highly suggest not using galvanized metal on any surface of a forge. For I looked into the case of Paw Paw Wilson, who died heating galvanized metal.
what if i am far away and hold my breath when getting close
chirman234 years ago
The coffee can will eventually burn away. If this is something that you are going to do many times I advise pouring refractory cement between the outer edge and the center where the crucible and coal is held.
junits154 years ago
what do you do with your aluminum?
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