Originally published at: https://boingboing.net/2018/03/09/watch-this-guy-melt-down-1000.html
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I take the lazy way out - stomp them flat, bag them, accumulate a few trash bags full, and take them to the scrap yard. Not a whole lot of money in the grand scheme of things, but still it nets enough cash to be worth it. Last time I turned in some bags it was about 45 cents per pound.
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I really wonder about using old soda cans as a source for Al casting projects as cans are made from a high manganese, low copper alloy that really only gets its strength from being cold-worked. I suppose if one is only doing decorative that wouldn’t be so critical, but I’d look to other types of scrap for anything structural.
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45 cents per pound
Surely the deposit is worth much more than that?
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I used chopped up extruded aluminum edging from old plexiglass rack doors, because I didn’t want to have to melt hundreds of cans to make a single casting.
As Andrea noted, you’re just going to have insane amounts of dross using cans.
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Reminds me: This guy used a turkey fryer in his backyard to melt lead tire weights into a keel for his boat project. Yikes.
Where I live, it is 10 cents per can. So that is $100 worth of cans…
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Doesn’t “aluminium” have a crazy high melting point? Isn’t that why it wasn’t really discovered until the 19th century?
Fantastic! Love the smelt!
Here’s an oldie but goodie:
The portable furnace is really quite clever.
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I’ve tried it too, and decided it wasn’t worth it. At least 1/3 dross, nasty fumes from the coatings burning off, and the finished product was pretty weak.
Old Al engine parts make great scrap for melting. They’re alloys designed for casting and can be broken up into nice sizes. A little surface contamination, but manageable.
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What deposit? I live in Illinois, no such thing here, unfortunately.
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Not really (melting point about 660°C, vs. 1538°C for iron), but aluminum oxide is difficult to smelt, and it took the development of the electric arc furnace to make large-scale production practical.
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You get about $1.75/lb at the recycling place for aluminum cans – although I assume that’s a function of the deposit, not the spot price of aluminum
I feel like this is the opposite of Primitive Technology:
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Huuuuge ingots!!!
I just like the sound of saying it out loud. Sometimes I get a dose of the “sillies”
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Engine blocks are mostlly 319 alloy - high Si, high Cu, ideal for casting and can be heat treated after to T5. Good choice.
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Aluminium is smelted by electrolysis rather than an electric arc in the Hall–Héroult process.
The aluminium oxide is dissolved in molten cryolite (sodium hexafluoroaluminate) at about 1000C in a steel pot which forms the cathode. The anode is made from a carbon rod which is dipped into the molten alumina and a massive current applied. The carbon reacts with oxygen in the alumina to produce carbon dioxide and carbon monoxide.
Before this process came along, aluminium was produced by reacting aluminium trichloride with sodium metal. As you said, it was formidably expensive with aluminium metal being a scientific wonder when it was exhibited in 1855 at a cost of about $500 per pound. 100 ounces of aluminium were used to cap the Washington Monument in 1884 - at the time it was by far the largest piece of aluminium ever made. By the 1890s, it was a consumer product with aluminium dishes and cutlery coming on to the market.
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€ 0.25 deposit per can over here.
That’s actually what I was thinking of… guess I oversimplified a bit.
Don’t aluminum cans have some kind of plastic coating inside? Probably more of that in the dross than anything else.
