I melted aluminum!

Melting Aluminum

Note: this is very dangerous. Melted aluminum is hot enough to vaporize human flesh. Dropping molten aluminum on water causes flash vaporization and hurls the molten metal everywhere, like a fragmentation grenade. Be VERY CAREFUL if you do this. In a world of way too many stupid warning signs everywhere, this is a warning that is very real: take it very seriously.

A long time dream come true: I melted aluminum this afternoon!

I've wanted to do this for a long time now: I never believed it would be particularly difficult, and I was right! Anybody can melt aluminum for practically free. :-)

I've always had a thing about recycling - I generally am against it, giving away my valuable materials for somebody else to benefit from: on the other hand, I have no way of taking advantage of them myself.

Melting aluminum changes that. I can make cast metal objects, and keep my own aluminum. Aluminum is a valuable metal, but it's essentially free - you can get free aluminum garbage everywhere: people mostly want you to haul it away. :-)

First, I took a couple of coffee cans (free off Kijiji). The first coffee can was going to be my fire chamber. I drilled a bunch of holes in the bottom of it for airflow.

The second coffee can was going to be my air chamber. I Dremelled a round hole near the bottom of the can for the forced air to come in. The fire chamber had to sit on top of this can, and to make it secure, I chopped slits down the side of the air chamber can so that it could expand and grab hold of the fire chamber can.

Next, I got an old blower out of a fume extractor (free off Kijiji). I wired a Decora lightswitch to it (free from my junk box from previous home renovations ), and a mains power cord (free from a dead hair dryer I got from Crystal at work). I built a air director from the wide rectangular output port on the blower to a small round hole that matched the hole in the air chamber. This was made out of aluminum foil (free-ish from Lisa's cupboard), and taped with foil tape (free from previous home renos).

Lisa got me a bean can (free from her cupboard), I bent a spout on it with pliers, drilled two holes near the top, and made a loop of steel single strand fence wire (free from our quarter mile spool that we use for fencing) as a handle. Instant cheap crucible. Won't last too many melts, but for free, can't complain!

Finally, I filled the fire chamber up with charcoal ($10 for an expensive bag of lump charcoal at Home Depot - it's all they had) packed around the crucible. Doused with lighter fluid ($5 at Home Depot), it started easily. Once the flames died down a bit, I turned on the blower, and was rewarded with a dull roar of fire. Soon, the bean can glowed red hot. I dropped a bunch of crushed soda tins (free garbage) into the fire, they melted, and I poured the aluminum out into a coffee can of sand.

Basically free. The only thing I paid for was the charcoal, of which I used probably 50 cents or so, and the lighter fluid, which I used pretty aggressively, but still -- this was a super cheap project.

If you're even cheaper, you can make your own charcoal. :-)

The result was the awesome ingot in the pictures! Hooray! This was awesome!

The furnace itself held up very well. It's still outside with cooling coals in it. The label burned/melted off, but otherwise, it's in good shape. The crucible also held up well. I wouldn't trust it through too many melts (I don't want to lose aluminum), but it's fine for single use melting.

I used around 8 cans (I didn't count beforehand), hammered flat with a hammer. The ingot (or rather, "mishapen blob" :-) weighs 1.95 ounces. I didn't weight the slag, but I got about 1/3 aluminum by volume. The slag is pretty neat nasty looking stuff. It's still outside also.

A fun project. Recommended (but heed the warnings at the beginning of this post!)