Adventures with Aluminum

[canid]

I did my first aluminum smelt today. This was just a test melt to test the capabilities of my weedburner forge for the task, and the product is not clean yet.

http://s602.photobucket.com/user/can...0in%20Aluminum

I want to try green sand casting, with my first piece to be a lathe headstock. I don't know if I'll get around to it any time soon, but I was amazed at the ease of this.

[canid]

I know what to cast first: I could do a cast-around the tang aluminum bolster on one of my knives.

[gryffynklm]

Great post, another one of those things I have thought about and never got past the thought part. Very Cool... ah HOT.

[crashdive123]

Neat project (not gonna say cool like Karl did).

[Winter]

I know what to cast first: I could do a cast-around the tang aluminum bolster on one of my knives.

Great plan. I was led to believe aluminum has some pretty bad fumes.

[canid]

It probably does. I can't think of many metals one would like to smelt without proper ventilation. It doesn't (cheaply) get better than doing it outdoors and standing upwind at a reasonable distance.

[Rick]

Dude, you spilled some on your keyboard.

Couldn't you use aluminum cans to melt? That would be cheaper than buying aluminum stock. Of course it would probably take about a million cans to make 6 ounces. Still.......

[woodsman86]

I heard melting can leaves a lot of impurities because the labels but the tabs are pure. Aluminum can be nasty stuff, just don't eat a sandwich while hanging over the pot When I was welding it regularly, I use to have to clean the soot from my shield about every day. Neat project and I like the torch setup.

[canid]

I'm using cans and all the scrap I can round up. I haven't taken in the recycling in a while since I worked a lot last month (I usually take it in after I've been broke for a bit and even the refrigerator's starting to get hungry). I've got some scrap 'C' channel from something a friend built which never worked right, some pie tins of the sort that are too thick to be disposable/single-use but too thin to live long. Because I scrap and scavenge electronics, I accumulate a lot of little heat sinks. To be honest, I'm going to have to come up with better ideas, and might have to buy scrap from the junk yard before all is said and done.

In all, It looks like a 40" lathe bed is going to take a darned lot of beer cans. There are 33.35 of them to a pound, and that particular pour would require about 60lb. I just can't drink that much any more, I'm getting old.

[canid]

Oh, and yes; smelting cans creates more dross than smelting bare aluminum. It appears to be about 5-10% of the smelt by volume. This is not too terribly bad.


What I did notice when I chucked a couple cans in there is this: cans float. as they melt down, the air trapped inside them remains and you poke and poke, but they just bob there, dragging it out like the last scene in Terminator II

[hunter63]

I think I wouold stay away from cans.....moisture tends to really cause some intresting explosions....( I talking melting lead)....

Saw a set up at the Mother Earth News Village in the '80's...was made with a brick/ferro cement lined charcoal grill with a blower....they were pouring knobs for a project.

Making molds is a real an art as far as vents and runners for complete filling and such.......cool stuff.

[canid]

Cans are pretty easy to dry when you have a giant torch. You can also pre-dry your flux. The big drawbacks seem to be the numbers required and the smell. Burning that much paint is slightly stinky. I'd imagine with some fluxes and degassers (e.g. chlorides) that the gases are worse too.

[randyt]

that's awesome. I started to put together a foundry outfit. Made a waste oil burner, picked up three bags of kast-o-lite 30, scrounged up my granddads crucibles, flasks, rammers and etc. Even have a pile of aluminum automotive bell housings and such. Did I ever mention we don't throw nary a thing out LOL. Anyhoo there just isn't enough time in a day at times. Soon, soon, LOL.

[canid]

Well, this setup could be thrown together in an hour, from start to pour. I hear you about the not throwing stuff out.

Just be careful it's all aluminum. Don't want to throw any magnesium parts in there by mistake

[randyt]

I wondered about a big old magnesium block. I've melted aluminum in a cast iron plumbers pot over a plumbers furnace. Does work ok but I eventually want to melt brass.

[canid]

well, depending on how much magnesium is in the alloy, that could be 30 minutes of instant daylight. remember that magnesium autoignites at about 2/3 the temperature that aluminum melts at, and it's alloys can ignite in the neighborhood of 1200-1600f.

[randyt]

how can magnesium be identified? cut off a tiny chunk and torch it up? I doubt there is any in the pile but should play it safe.

[canid]

you can shave a sliver off pretty easilly. anything that burns in a map torch should probably not go into the pot.

Mg is more reactive than aluminum too, so there are many acids/oxidizers which will react noticably with Mg but not Al.

[gunaroo]

well, depending on how much magnesium is in the alloy, that could be 30 minutes of instant daylight. remember that magnesium autoignites at about 2/3 the temperature that aluminum melts at, and it's alloys can ignite in the neighborhood of 1200-1600f.

I think you are worrying too much. I have melted aluminum and magnesium together to form "magnalium" alloy, which is an easily-powdered alloy for pyrotechnics uses.

Regarding the melting of cans: don't. There are huge amounts of slag given off from the labels and oxidation. Aluminum wire if you can source it as scrap is a great source.

The melter in the initial post is nice! I once built an electric furnace for aluminum melting from a waffle iron. I made the furnace/kiln body in a 5 gal bucket using a mixture of cement and pearlite. A hole was left in the middle by allowing it to set with a empty soup can in the middle. The resistance wire from a waffle iron was cut in half , used to encircle the hole made by a soup can (previously removed) and hooked up to a variac. Got to orange heat no problem and could melt aluminum in a ceramic crucible or steel can easily.

[edr730]

I've melted what I thought was aluminum on my woodstove accidentaly. It was a hot, but not exceptionally hot fire. The stovepipe wasn't red. It completely turned to liquid and drained off the side of the stove.