Step 10: Making the mold

If you don't want to make a mold, just some metal blobs (ingots), you can pour the molten aluminum into a muffin tin. The ingots can be re-melted later if you need the metal.

Making a sand mold is easy. All you need is some sand and a way to imprint a design in it.

You could do this with a stick or something, but it probably wouldn't turn out well. I find you get the best results when you use something with a 3-D pattern on it. In this instance I used some pottery, I found at the flea market.

If you have a friend (or friends) working with you, they could make a cool design, while you melt the metal.

Now all that's left to do is prepare your work-space.
<p>i like it so much</p>
what sand did you use and how much water do i put in the sand <br>
<p>I am going to use &quot;Paver Sand&quot; from Lowes. It is a fine grain sand which seems to pack better than their normal &quot;Play Sand&quot;. I will also add some clay dust made from unscented &amp; unclumping kitty litter to improve the packing properties.</p>
<p>Crucible: I use one of those &quot;squatty&quot; propane bottles from a propane torch that I filled with water and then cut with a metal cut-off blade in my skill-saw. It is plenty big enough to hold aluminum cans, and so far it has lasted 6 firings without signs of needing replaced. I did try to weld some handles on it, but I ended up burning a tiny hole near the top so I gave that up and just use a large pair of channel lock pliers to lift it out of the furnace. I made my furnace inside a 6 gallon bucket with a small plastic trash can (about 2 inch gap between them) and filled the gap with 50% Plaster with 50% sand mixture. The plastic trashcan burned out the first firing except a layer in the bottom that I pulled out after it cooled. I then drilled a 1 inch hole going into the bottom where I inserted an iron pipe. On the other end of the iron pipe I put a 90 degree elbow and feed it air from a slip-joint PVC pipe setup of 1-1/2&quot; PVC inside 2&quot; PVC then an old hair dryer as the blower into the 2&quot; PVC. I could have Duct Taped the PVC but I like the slip-joint for positioning. The hair dryer has a &quot;cold&quot; selection and then 2 air speeds. Bought it at Goodwill for $4. I also made a top out of the lid, but it is starting to flake off on the inside. The lid keeps the heat in better and everything works faster. I use welder's gloves to remove the lid (with the blower off) and to handle the pliers as I pour. I am still experimenting with ingot molds. So far my best results are from a steel mini-muffin tin. I plan to make my metal molds from &quot;Paver Sand&quot; mixed with clay dust (made from unscented/plain cat litter) and pack it into frames to make impressions of my items to be molded. Here are some of the pictures I took.</p>
<p>During operations the blower pipe is not inserted inside the burning chamber, just up to the charcoal. Light the charcoal and after it is lit for a while turn on the blower at low setting. After charcoal is well lit turn up the blower to high.</p>
what did you use for a crucible?
A tin can.
That was certainly a steel can. BTW, I've seen a lot of aluminum soup cans lately. They usually have pull-tab tops. Before you use a food can for a crucible, check it with a magnet. The best cheap crucible for aluminum and zinc alloys is a short piece of steel pipe with a piece of steel plate welded over one end. I haven't checked with local welding shops, but it would probably cost less than the cheapest clay-graphite crucible from Budget Casting Supply. There are a *lot* of web sites devoted to amateur foundry. www.backyardmetalcasting.con is a good start.<br/>
I think i adress that most cans are made out of steel somewhere, but for the life of me, i can't figure out where. Probably in the comments somewhere. Also, a welded crucible would probably work better, but I'm trying to make this build as simple as possible so others with no experience can replicate it.
<p>what is your mold made of?</p>
Have you ever tried a ceramic crucible? I was wondering if you would get a purer product if you didn't have the ferric metal possibly alloying minutely with the aluminum.
A ceramic crucible would be awesome. But I'm trying to keep it cheap and only use garbage for my materials.<br /> <br /> Also, I don't think the steel alloys with the&nbsp;aluminum at all, but rust flakes might get in the melt if you use the same crucible more than once.
&nbsp;Could you make a crucible out of plaster? (since you could cast the aluminum into it anyway?)
Plaster, like portland cement, sets by a hydration reaction.&nbsp; Get it hot enough and it dehydrates, turning back into dust.&nbsp; The furnace is going to be a lot hotter than a mold full of molten metal.<br />
Can you use a glass bottle or container as a crucible? I&nbsp;know it has a much higher melting point than aluminum and is somewhat easier to come by than steel.<br />
The short answer, no.<br /> <br /> The long answer no becuz it'll explode, or at least crack, which would waste all the aluminum.
<p>I am not sure if it would be any good as a crucible but WalMart sells stainless steel cups with handles for camping for like, I think $9.</p>
I can make you some stainless crucibles if you would like or carbon steel. I take paypal so you are covered and ship USPS.just need to know the size and what kind of material you would like. 256-309-9406 is my number. Thanks.
my crucible was an old fire extinguisher that i cut the top off with a sawsall. works great!
<p>Were did u get a fire extinguisher made of steel? Cuz everything is made out of Aluminum now!!</p>
Here are a few photos of success in action
Here are a few photos of success in action
I can confirm that this definitely works
<p>this is just plain awesome....</p>
<p>what a great idea, for a number of reason. skys the the limit with what you could make with this stuff</p>
<p>awesome me and my friend need to make something like this :)</p>
Made it and it worked! Make sure to have enough coals, start by putting a small amount of metal first and wear protective glasses
<p>Excellent instructable!</p>
that is cool. I might try that. <br>
Wonderful instructable! Aside from the lack of face shield that is. I am excited to see what new designs you come up with.
This is very creative. I was actually looking for <a href="http://lucedheatingfurnacesairconditioning.ca" rel="nofollow">furnaces here in Edmonton</a> and this picture popped up. Not exactly what I am looking for, but it is really cool. Thanks for sharing!
can you use wood insted of charcoal.
No, Wood will not burn hot enough
wood does burn hot enough. i do it all the time.. in fact thats all i use to smelt my aluminum. granted you use alot of wood but if your like me and you have alot of trees on your property then its no problem. <br>
bullshit, i forge with wood. and what do you think charcoal is made of? (hardwood)
Yes you can i have used wood alot just cut it into kindling then it will turn into hot coals quickly which are easily able to produce the heat required for melting aluminium
what kind of gas mask filter will cleanse the toxic fumes form the cans?
is there a way to set it up to melt stainless steel?
im going to make this just got to find the coffee tins <br>
Question,i have a heat gun which i use to take off formica when doing remodel and use it to melt ice. would this be more effective?
No. <br> <br>Hot air is less dense than cold air, and consequently contains less oxygen. <br>I know it's counter-intuitive, but colder air burns better.
that's kind of funny but interesting :) thanx,time to hit up a goodwill for a dryer.
Cool, I've been looking for a good foundry instructable, looks like I'll be taking a trip to the goodwill for a cheap hairdryers.
what if you just removed the paint from the cans?
cannot stess the importance of a face mask here. no matter how well prepared you are, unexpected s#!+ happens. a cheap lexan face mask from a local welding supply is a lot cheaper than skin grafts - and a hell of a lot less painful.
P.S. i got my degree i bronze casting specifically, and i have a ton of experience with all manner of aluminum casting. i know whereof i speak.
Thanks for the advice. You can get a degree in casting? That's awesome, I'll have to look into that.
Not bronze casting specifically, no LOL. But bronze was my emphasis in my sculpture degree, which is as close as one gets, I suspect.
put a rol of pennys in, they if its hot enought, they will burn blue.
DO Not do this with pennys. This can hurt you fast. Most pennys now are made out of Zinc and will poison you if you breathe the fumes when it is melted or burning. <br>They have a very thin coating of copper over the zinc cast. <br>If you want to melt copper, use old copper tubing or wire with the plastic removed. Just make sure it is realy copper all the way through. <br> <br>And to prevent oxidation a little bit of hundred mule team borax floating on top works like a champ.

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