There are many guides and many ideas I've collected and, being that I completed this (the first one... I made a completely new setup just for this instructible... you should feel special.) within two days and most importantly... cheaply.

My cousin /assistant / camera man and I created this instructable so we could share our wonderful smelting smelting experience and win the hearts and minds of the instructable community.


This instructible includes fire and molten metal.

Also; If you mortally wound yourself while duplicating this instructible, please delete this from your history internet history before dieing. i don't want to be held liable.


We shall begin.

Step 1: Parts / Tools

In retrospect, the parts / tools list quite long but it should be things that are easily available.

The most expensive thing was the torch. I'm really cheap but it turned out to be a rewarding investment.

The other parts are as follows:

Quick Setting Quickrete (I got a 20 lb bucket for under 10 bucks)
Something to mix the Quickrete in
Something to stir the Quickrete with
Large Coffee Can (6 inch)
Small Coffee Can (4 inch)
Hack Saw (or any metal cutting tool)
Drill (or metal punch or improvised hole making tool)
An empty 14.1 oz propane tank (make sure it's competently empty)
Scrap steel bar like from a printer, about a foot long (you can buy 5/8 steel bar at lowes)
A sharpie (or any marking tool)
Short (about 2 or 3 inches) iron or steel tube that the torch head fits in. (optional)
A ball peen hammer (any hammer will suffice)
Some propane gas (i buy the ones for camping stoves because their $4.38 for a 2 pack of 16.4 oz tanks.)
An oven (optional)
A vice. ( kinda optional. you could find another way but i find the vice necessary)
A mini muffin tin (optional. you just need something to pour the aluminum into.)
Some cheap thin steel wire (1/8 diameter max. but strong enough to hold some weight)

Step 2: A Suitable Crucible

So I took the empty 14.1oz and put it in the vice.

We used my hack saw to cut just under the seam then de-burred the edges.

If you look at the bottom you should see 4 holes. Use a marker to draw a line up the side in line with a hole.

Use the ball peen hammer (or any hammer) and bang out where the line is. This will make a spout. (may take a little working to get it right but as long as it's there, pouring will be easier)

Now draw lines up the sides from the holes adjacent from the side with the spout.

About 1/4 inch from the top, mark the line, and drill at that mark on both sides.

I used a drill but anything number of things could be used.

Make sure your metal bar fits in the holes.

Put on a pair of leather work gloves.

Now mark the center of the bar.

Heat it up over the torch.

When the metal turns red, bend it in half to make an acute angle but not completely in half. (see picture)

Quench the metal in some water and heat up the ends one at a time. Bend them in so they face each other.

Quench the ends and re heat the center bend. Unbend it and rebend it so the ends that you bent in fit into the holes in your half of a propane tank.

Quench the center bend and ensure that your new handle moves freely in it's holes.

You are now the proud parent of a crucible.

Step 3: The Forge

This is kind of difficult but has few steps.

Cut a hole in the side of the big can about an inch from the bottom.

Make sure the pipe fits. (you could use a piece of rolled up paper or cardboard.)

Use a can opener on the bottom of the small coffee can and cut a mouse hole shaped hole in the lower side. (make sure the pipe fits)

Wrap the small can in cardboard. (this is to make it easily removable.) and cut out the mouse hole in the cardboard.

Mix the quickrete. We used 11 cups of quickrete and about 2.5 cups of water.

Pack the quickrete tightly in the bottom of the can and up to the bottom of the hole.

Place the pipe in the hole and the small can in the big can with the pipe in the mouse hole. Try to center the small can.

You want the pipe to go in diagonally. This will help create a spiral of flames. (see picture)

Fill up the sides with quickrete and pack tightly.

We let it set for a bit then put it in the oven and set it to 400.

After 30 minutes take it out and pull out the small can and the cardboard.

Put it back in the oven for 2 hours. This will help eliminate the moisture.

Use oven mitts and take it out of the oven. and bring it to our work area.

Lite the torch and stick it in the pipe.

I suggest wearing eye protection.

This first firing is just to eliminate moisture. You may see steam coming from the cement.

Let it fire for about half an hour then let it dry overnight.

We put the crucible in during the first fire to help burn off the paint.

Step 4: Melting Aluminium

This is pretty much the most dangerous part so have water near by and wear thick leather or welding gloves as well as safety glasses and make sure the area is well ventilated.

You're going to want to fire it up and put in your crucible.

I'd wait until the bottom of the crucible is red hot. (just a personal preference.)

Start out with small pieces of aluminum. (I had "pipes" from an old wind chime.) You could use cans but they tend to have a lot of slag. I'd wait until you have a nice quantity of aluminum before using cans.

You'll probably have a rough start so go slow. After you get a good quantity of aluminum it will be able to maintain a melting temperature and you can melt down large pieces in seconds. I have found an old knock off of a razor scooter in th back of my garage that has worn out it's usefulness. I found a new use for it's aluminum.

I have found covering the crucible with the top half of the empty propane tank helps keep the heat in and keeps things moving along nicely.

I had a troublesome piece of scooter that didn't want to release it's steel screw so I dunked it in the pool of molten madness and that half didn't come back. A mallet made short work of the obstructing piece of metal and allowed us to make a deposit in our crucible.

After you either fill up your crucible or run out of aluminum, you need to scrape off the slag. The slag will be floating on the top and will look a little different than the metal underneath.

We used a scrap piece of metal to scrape off the slag. We used the same scrap to make a hook to pick up the crucible and another piece to fit in the holes on the bottom of the crucible so you can easily pour it. You could use a small screw driver for this.

Make sure you have something to pour the aluminum into. I am just going to save them for later so I'm pouring them into one of those "mini muffin" tins just because they're small and fit in the crucible. You could just use an impression in wet sand or something. Muffin tins are faster. But don't expect to use them for muffins again.

Pour gently into the mold of your choice. IT IS HOT! WEAR PROTECTIVE EQUIPMENT!

Because I'm impatient, I wait until the aluminum in the tins are solid then throw them into a can of water. The water may boil violently after a short delay. It is a sight to behold but dangerous.

You now have aluminum ingots.

Step 5: Now What?

We now have a lot of ingots. You now can use the rest of your free time planning on how to get a hold of a harbor freight micro-mini-lathe for $250.

I figure we could cast some blanks that can be worked in a tiny lathe but that's for later.

We'll Make an instructible on casting aluminum when we get it down to a simple science.

We hope you enjoyed this instructible and happy smelting.
Go on YouTube and "grant Thompson, the king of random: aluminum forge. He makes a great video on how to safely do this.
If I may correct myself, the video is called: mini metal foundry
<p>Just because <em>you</em> took a hack saw to an &quot;empty&quot; propane bottle and <em>you </em>weren't injured doesn't mean it's safe, or a good idea. I would think very carefully before advising others to try something like that. There will always be propane vapors left in the tank. Every time is a roll of the dice.</p>
<p>It seems to me the best way to ensure it's really empty is to attach an appliance (torch head, cook burner, heater, etc.) to the tank and open it up to expel the fuel.</p><p>If you wait until the heat-of-the-day to close it, then cut the tank at night, there will actually be a vacuum in it. A hack-saw will not produce sparks, (just don't use a grinder on it), and cut it slowly. I've never had a problem.</p>
<p>You're absolutely right. A good idea is to find a tank where you can unscrew the nozzle and then purge the remaining gas by first filling it with water.</p>
<p>Obviously, safety first - or at least a solid third. It's molten metal after all...</p><p> A little late to the post. So I've had a very similar foundry made for a while now made of Quickrete surfacing mix and sand in a steel bucket. It's also a solid fuel foundry (charcoal briquettes) with a small electric air mattress pump for air supply. Melting down aluminum is easy enough and for the price of a bag of charcoal, I can melt down 15-20 pounds of aluminum cans. Temp runs between about 1100 and 1900 deg F depending. If I cover the foundry (quickrete/sand cover a couple inches thick with a vent hole in the center) it will soften steel enough to cause a failure.</p><p> The problem for me has been the crucible. Tried steel milkshake tumblers. Failed about 20 cans in. Tried small empty fire extinguishers cut down to height. Failed after one or two pours. Haven't tried an empty propane bottle yet. I imagine they are about the same thickness as an extinguisher? Can anyone report how long these last for? If these fail, next will be schedule 40 stainless pipe with a welded bottom plate. Be cool if anyone has a lead on something similar...</p>
<p>I took the top of a fire extuingsjer that I thought would be the perfect crucible. </p><p>Fire extinguishers are often made from aluminum. They can do this since the pressure is very low, the gas used is safe, and the content is (obviously) non-flammable.</p><p>Propane is under much more pressure than the extinguisher, and being flammable even explosive has certain legal requirements, one of which I imagine is requiring either very thick aluminum (not economic) or using a stronger metal like steel.</p>
I have used a fire extinguisher cut in half for 20 bags of aluminum cans. Hasnt failed yet. I started with charcol to hear with hair dryer blowing my air. Moved upto a propane torch. I purchased a graphite crucible for copper and am buying a larger one for aluminum. They are on amazon.
<p>YES! same...stupid...problem...solution:1/4&quot; black steel pipe with an end cap. 1-1/2&quot; OD i think? 'bout 4&quot;-4.5&quot; long.</p><p>my brother-in-law throws boxes in a warehouse, and has on occasion moved empty industrial sized dumpsters 10ish feet across asphalt (we were at the beach and he REALLY wanted that parking space...)his strength is legendary in our circle of friends... I'm a shrimpy dude...</p><p>he grabbed one end in a pipe wrench, I grabbed the endcap in another pipe wrench, and we pushed in opposite directions, with all our might...i got pushed around the room... it has never leaked, has never split, broken, or warped...has processed probably about a hundred melts over 3 years of abuse... it's got some nasty scale on the outside, and it sucks to clean... but we can still wrench off the endcap, clean it, and the threads still meet back up when we put it back together. and we've had it glowing dull orange quite a few times!</p><p>only real downside is that with so much steel, it really sucks a lot of heat... but it also holds a lot of heat when it DOES get hot, which is nice if you need to do a bunch of back-to-back melts.<br></p>
Thank you so much i have been wanting to melt down some metal and smelt and this helps me alot thank you
<p>I am melting cans and find a lot of slag in the aluminium melt,what can I use to float the slag off and what can I use to degas the aluminium.</p>
I use a spoon of char coal ash and a spoon of rock sea salt . they act as Degassing agent and flux . the salt you get at the food isle at the store.
I hear using a salt substitute like no salt is a much better one to use. I bought a 2 pound bag of borax i also heard works well. Im going to try on my next batch. I have 10 bags of cans ready to go. Just looking for a day its not 100 degrees to work.
Well I plan to make one of these but my question is, after you pour the aluminum into the muffin tins, how do you get them out? I know this may sound stupid so please ignore my ignorance.
I dont even tap mine. The molten metal doesn't stick. I take the garden hose and spray it over the top until the steam and hissing stops. Then use tongs to pick them out or dump them into a 5 gallon bucket of cool water.
<p>I just semi-lightley hit the bottom of the muffin pan </p>
<p>Move the tray onto a well-cured concrete pad or some rocks and spray the bottom with water. The muffin tray will be red hot so be super careful as it will steam and pop. Just keep putting water on it and once the bottom cools, spray some on the top. Eventually, the aluminum will shrink and you can simply turn the muffin tin upside down and they will fall out.</p>
<p>Hi to Everyone,</p><p>Regarding the safety issues related to this and numerous other posts...... I think anyone that takes instructions directly from a post on the internet without thoroughly researching the project and safe practices related to that project should be a poster child for Darwin's theory of evolution. People forget that the #1 cause of death in humans is not heart disease, cancer or any medical condition.....It's STUPIDITY! </p><p>Dumb Kills!</p>
<p>Its their choice to be stupid.</p>
<p>It's my choice to be compassionate... besides, they'll make such WONDERFUL bait during the zombie apocalypse!</p>
<p>I'm a little worried about using quikrete as an insulator... all ceramics have the potential to experience a steam explosion when exposed to molten metals. The moisture trapped inside the 'crete turns to steam, expands and eventually ruptures the construction, flinging hot metal, and sharp fragments of stone in all directions. (look this stuff up, it's pretty nasty, and yeah... it DOES happen). I think a better mix would be sand/plaster of paris/water. Little cost difference ($5 or so) a MUCH better insulator, and it removes the danger of a steam explosion. If you feel so inclined, you might toss in a short segment about that in this instructable? Thanks!</p>
<p>Absolutely right. I have one made of quickrete/sand that's been cured for a couple weeks before use. I also pre-heat it before I fire it up to make sure there's no residual moisture. Safety first - or at least a solid third.</p>
<p>I wouldn't be concerned with the moisture on the *outside* of the quickcrete. The *internal* moisture... the moisture that's necessary for any ceramic to cure, and gets trapped in airtight pockets INSIDE the concrete. like... in ALL ceramics... ever ( i think?) not sure that preheating is going to do anything about this...</p><p>I had just bought a house, and the previous owner had a bunch of 2'x2'x2&quot; pavers laying around. the pretty textured ones that you can buy at walmart, you know?</p><p>They'd been sitting in the hot sun for a few days, 90 deg+ easy, and felt pretty dry. I use lump coal in my forge, because I think it burns hotter... when lump charcoal gets hot, and you blast too much air at it, it throws out showers and showers of sparks... I call them &quot;Fire Bees&quot; ....because they sting you, and they're made of fire...</p><p>anyways, I figure I'll just slap this 2'x2'x2&quot; decorative paver on top of the forge, to contain the fire bees... everything was fine for the first few heats of the steel i was hammering, probably just shy of 2000degf. But the paver was getting too hot to handle, taking on and off the forge, even with welding gloves on. So I pulled it off and was walking it over to a spot off in some grass where I could put it down somewhere safe. just as I started to drop/toss it, the face, that was facing away from me exploded. Sounded JUST like my 9mm glock19 going off, Sent pieces of stone the size of quarters bouncing off my house something like 30 ft away... some of them had enough energy to bounce and shower back on me...albeit harmlessly&quot;. </p><p>If this were to happen during an aluminum melt... it'd splash molten aluminum everywhere... google says aluminum melts at 1200degf or so... and that 9/10 doctors agree that 1200degf aluminum is harmful to the average guy's skin...</p><p>:( I guess that's a long winded story either about how a paver saved me from a ninja armed with a 9mm, or how steam explosions are stupid, dangerous, and unpredictable....and stupid again. Cheers!</p>
<p>Just a idea to make your forging much easier. Check this out from Budget Casting supple. Also I have been a mason for over 40 years I know first hand that fire and concrete don't mix, I would never put a flame to concrete. I have built hundreds of fire places and masonry smokers and grills.Get a book on green sand molds you can't get any cheaper than making your molds from sand. Good source is Lindsay Publications Inc. Bradley IL.</p><p>I copied this from Budget Casting Supple. </p><p>A crucible is <br>needed to withstand the extreme temperatures encountered in melting <br>metals. The crucible material must have a much higher melting point than <br> that of the metal being melted and it must have good strength even when <br> white hot.</p><p> <br>It is possible to use a home made steel crucible to melt metals such as <br>zinc and aluminum, because these metals melt at a temperature well below <br> that of steel. However scaling (flaking) of a steel crucible interior <br>surface is a problem. This scale can contaminate the melt and thin the <br>crucible walls rather quickly. Steel crucibles will work if you are just <br> getting started and don't mind dealing with the scaling.</p><p> <br>Common refractory materials used in crucible construction are <br>clay-graphite, and carbon bonded silicon-carbide. These materials can <br>withstand the highest temperatures in typical foundry work. Silicon <br>carbide has the added advantage of being a very durable material.</p><p> <br>Our Clay Graphite Bilge Shape crucibles are rated for 2750 &deg;F (1510 &deg;C). <br> They will handle zinc, aluminum, brass / bronze, silver and gold <br>alloys. The manufacturer states they can be used for cast iron. Made in <br>the United States!</p><p> <br>The &quot;A&quot; shaped crucibles are useful for metals up to 2000 &deg;F (1093&deg;C). <br>They will handle zinc, aluminum, brass / bronze, silver and gold alloys. <br> Made in China.</p><p> <br>The Silicon Carbide Bilge crucibles are rated for 2750 &deg;F (1510 &deg;C). <br>They will handle zinc, aluminum, brass / bronze, silver and gold alloys. <br> Made in Mexico.</p>
<p>Thanks for the lead! I've been melting down steel vessels like it's the cool thing to do. </p>
<p>Oh I forgot that you can buy a crucible from Budget Supple for as low as $22.00</p><p>Seem to me you would be better off buying one than making one your self. at such a low cost and you would get better resuilts from your forging.</p>
<p>Which of the three crucibles would you prefer?</p><p>And what other materials would I use to do a aluminum anthill project? </p>
<p>Notl1 what would you use as an insulator if concrete can explode?</p>
<p>sorry...</p><p>JUST saw this...</p><p>I use Plaster of Paris mixed with very fine sand and water. in a 5 gallon steel bucket.</p><p>I don't keep track of the mix. I do it by feel/consistency: it should be like thick soup, not depression chili. take a look at &quot;Grant Thompson&quot; (kingofrandom) on youtube. he's got some top notch videos on this specifically.</p><p>I typically try to make the walls nice and thick. 1.5&quot; or so, and 1.5&quot; thick on the bottom.</p><p>sorry for the super delayed response... doesn't look like you responded to me, so I never got a notification...</p>
<p>What termperature does that concrete withstand upto? I cant find any info on it.</p>
<p>thank you for your very helpful guide I hope you'll understand how helpful you really are to all the people who see this. I would have had to search for hour or days if it weren't for you. SO THANK YOU</p>
<p>To Mgr12,</p><p>If you are going to hate on someone, at least spell everything correctly and actually think about what you are saying. Chances are if someone is reading this, they know that fire is dangerous, and that melting some metals release harmful gases. and if they don't chances are they are still researching what they are doing.</p>
<p>Don't blame him, he's probably from New York where any soft drink larger than 16 ounces is considered a risk to safety. Or California, where literally everything causes some form of cancer.</p>
<p>As far as a propane tank crucible:</p><p>1: make sure tank is empty.</p><p>2: make sure tank is empty</p><p>Then:</p><p> a: light a small camp type fire </p><p> b: have a protective barrier pre set</p><p> b1: Make sure you understand b: then place tank in fire</p><p> c: walk rapidly to protective barrier (b:) 10 yards+</p><p> d: get a gun and fire a round through top of propane tank</p><p> e: fire 2nd round at tank if any doubt 1st round hit</p><p> f: retrieve tank (retrieve next day if unsure of first 2 rounds</p><p> f1: Shoot another round next day</p><p> g: Finally, cut tank as you see fit</p><p>3: Foot note for pros: </p><p>Try with full tank, but double distance to protective barrier and have &quot;friend&quot; place tank in fire. Results......impressive, but don't expect a usable crucible via this method.</p><p>4: COME ON PEOPLE...if unsure of any steps required to do any of this safely DO NOT ATTEMPT. Once Forge is built the true danger shows up. If concerned about steps.....you have to far to go to MELT METAL safely. Fumes, heat, reactions via moisture or chemicals, gas build-up, splatter, slag, fire, burn through, etc......molten metal is easy to achieve, what to do with it once liquid, that is the true danger. Good luck all. </p>
<p>Taking the valve off then filling it completely with water is another good way of verifying that all the gas is out and it's safe to cut.</p>
Awesome instructable <br><br>The one thing that caused some concern for me was cutting into a pressurized container. Even though you make sure it's empty. I've seen tanks explode just be careful is all.
It's easy to depressurization most tanks like that.I'm surprised though that in this post they don't say how
What were to happen if you made your furnace in dirt would it make much a difference
Hi I really the idea of this cuz I've been thinking of what I could use as a crucible in my forge and I saw this. I was wondering how do you make sure the butane tank (the one that will be the crucible) is completely empty? I showed my dad this and he was like "NO!", but I wasn't about to cut into a pressurized tank like that. We have an "empty" tank but I'm not sure how pressurized it still is. So how do you depressurize it?
Easy take a valve tool and remove the Schrader core out doors... fill the cylinder completely with water then empty it and feel free to cut away
<p>best way is to hook up the torch head to the propane tank your going to use and hold it under water. if bubbles rise from the tip then it still has pressure, if not then you should be fine. i am not liable for stupidity though </p>
<p>I have a question for you.. Do you think A home made coal forge can be made out of aluminum? Minus the fire pot of course. </p>
Look up a blacksmith forge you will find they are cast iron pans... heat rises... coal coke and ash insulates the bottom of the forge pan.. the air is blown from the hand crank blower through the coal to increase its heat output..
<p>I don't think so. I think it would be unsafe to construct the forge out of anything less than iron/steel. The inner surface should be refractory cement (or firebrick) as well. Aside from the risk of overheating the aluminum, the stability/strength of the iron is desired.</p>
<p>question -- what would happen if you mixed fine glass powder smaller then sand with the molten aluminium and mixed them together why'll the aluminium is in liquid form </p><p>is their a chance of EXPLOSION or will it just make the finished product brittle pending on the amount added </p>
This is ironic you asked about molten aluminum and glass... glass charge is actually spread across molten aluminum beds to make sheet glass.. glass floats on the surface of molten aluminum.
<p>Sort of going off ash springer, the explosiveness in thermite is all about how readily aluminum oxidizes, and the heat that is produced from the reaction. You'd have to do an energy balance to figure out whether there is an energy deficit or increase. Keep in mind there is a lot of free energy in molten aluminum. <br>In the case that the oxygen molecules from SiO2 don't explosively move to the aluminum molecules, you'd still have a really brittle product - I guess thats what you want, so it might be worth a try. <br>Definitely do the energy balance though to evaluate the risk..Then post the results up here! Sounds like an interesting idea. Whats the goal in extra brittle aluminum? b/c another solution is to just leave the melt out and oxidizing or restir the dross back through the melt.</p>
<p>GOOD POINT ! i think there is a chance not of explosion but of intense thermic reaction perhaps , which may well end in explosion my pyro chemistry is not my area but alot of pyro based products are made from aluminium flash powder for example now silicon dioxide may well make a thermite when mixed with powdered aluminium but im unsure because both will be in liquid phase whether there would be enough surface area to cause a reaction as one would expect liquid silicon dioxide and liquid aluminium + tin + byproduct annealing products, to all be very different in density and not mix well (you avoid agitating the pot while smelting alli) the sodium lpercarbonate used to seperate off the label junk and tin impurities adds another possibility. thats not an answer just my thoughts evoked by your statement, try it why not but be very careful as thats a very big dangerous cherry bomb if what you suggest happens. </p>
<p>I made this, based on another persons build. Worked great... actually... mine worked too good. We accidentially melted the STEEL propane tank used for melting the metal. So apparently I need a better crucible.</p>

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More by WesDoesStuff:Ultimate Guide to Making a Cheap but Effective Aluminium Forge.  Extracting (almost pure) Caffeine from Caffeine Pills. 
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