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How To Make The Mini Metal Foundry by The King of Random

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How to make a simple backyard foundry for less than $20, for melting popcans, and casting aluminum.

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Step 1: Watch the Video

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The King of Randomwww.thekingofrandom.com

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foundry metal meltingpop can foundry soda can foundrybackyard foundry backyard sciencemetal working diy science experimentscience demonstration

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WARNING: Charcoal foundries can reach temperatures in excess of 1,000C,which is well above the melting point of hobbyists. This project should only beattempted with adequate knowledge and training, proper protective safety gear,and in a fire resistant area with adequate ventilation. The sparks flying from thefoundry can ignite fires, and the fumes from burning dross can be toxic. Usecaution and common sense. Use of this video content is at your own risk.

Step 2: The Mini Metal Foundry

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METAL MELTER!by The King of Random

In this project youll see how to use equal parts of sand and plaster, to make asimple backyard foundry, thats powerful enough to melt scrap metal inseconds, but still pleasant enough keep around for decoration.

Step 3: Things You'll Need

Start this project with a big bag of play sand, and some plaster of paris. Bothof which you can find at your local hardware store, for under $20.

Youll also need a 10 quart steel bucket, and a tablecloth to cover anythingimportant, because chances are this is going to get a bit messy.

A 2.5 quart bucket can be used for measuring the ingredients, but it alsoserves a more important purpose that youll see in just a second.

The recipe for this makeshift refractory lining, is 1-3/4 buckets full (21 cups) ofplaster of paris, 1-3/4 buckets full (21 cups) of sand. And 1-1/4 buckets, filled(15 cups) with water.

Step 4: Refractory Mix

The moment the water touches the dry mix, the clock starts ticking. Youve onlygot about 15 minutes before it all hardens up. So get busy mixing everythingtogether.

Its really important to get all the dry powder wet, and work out any lumps asquickly as possible.

After mixing for a couple of minutes, it should be fairly runny, and roughly allthe same color. When youre convinced there arent any clumps of powder leftin the bucket, the refractory mix is ready for pouring.

Carefully transfer it to the steel bucket as slowly as practical, to minimize thesplattering. There should be just enough fluid to fill the bucket about 3 fromthe top. Now bring back the plastic measuring bucket, and use it to form thecenter of the foundry.

Fill the bucket with water, to give it a bit of weight, but anything like sand orrocks will work as well. As you push the bucket into the center, the mixturerises upward, but it wont spill out.

Before the mix is starts to firm up, try working the bucket up and down a fewtimes, to help level it before it sets. Now hold still for 2 to 3 minutes. This willgive the plaster just enough time to harden, so the bucket stays in place, evenwhen you let go.

Time for a little cleanup.

Step 5: Clean Up

Everything will still need about an hour to really harden up, but the plasters stillsoft enough that you can clean and shape it to look really good. And whileyoure here we may as well wipe the bucket down as well.

Dampen a rag and gently drag it around the top, the surface cleans up prettynicely, and gets a cool texture in the process. When it looks the way you wantit too, simply leave it for about an hour.

While youre waiting, turn an old steel fire extinguisher, into a custom crucible.

Step 6: Making the Crucible

You can tell its made from steel because a magnet sticks to it. And magnetswont do that to aluminum.

Depressurize the tank and unscrew the valve from the top, to make it safe andeasy to cut in half with a hacksaw. Which should happen in less than a minute.

The bottom part of the extinguisher is what you want for the crucible, becauseits basically a steel cup 3 in diameter, and 5 tall. Thats going to be perfectfor your custom backyard foundry.

Step 7: Making It Professional

At this point, the plaster should be pretty well set, so dump the water from thebucket, then use something like a pair of channel locks, to grip one edge of thepail, and pull gently toward the center.

Grip it with both hands and give it a bit of a twist, you can see the wholebucket pops loose, and pulls right out. This just created an amazingly smoothsurface, which gives this makeshift foundry, a surprisingly professional look.

The only features you are missing now, are an air supply port, and a lid, somake those next.

Step 8: Lid & Supply Port

A 1-3/8 (35mm) hole saw is the perfect size for accommodating this 1 steeltubing, and if you center the metal cutting blade with the top line on the bucket,you can carefully begin cutting through the metal wall.

Once through the metal, its easy to burrow down at about a 30 angle becausethe plaster hasnt fully cured, and cuts away like butter.

Now you have a tight, downward sloping hole, that the blower tube fits perfectlyinto, and its strategically placed, a few inches up from the bottom. This way, ifa crucible fails, and dumps molten metal into the foundry, it will stay in thefoundry, instead of dangerously flowing out of the pipe.

The blower tube is really easy to make. Start with a 1 steel pipe. This is thebusiness end that will sit next to the hot coals in the foundry. Youre alsogoing to need a 1" PVC coupling (Slip x FIPT), as well as some 1 PVC pipe.

You can see the threads on one half the coupling screw onto the steel pipe,and the slip adaptor on the other end, simply pushes onto the PVC tube. Itsthat easy.

Now go one step further and make a lid to help retain the heat.

Get a couple of 4 U-bolts from the hardware store and stand them upright in a5 quart, bigmouth bucket, filled with a half-measure of our insulating mix. (10

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cups plaster, 10 cups sand ,7 cups water).

After an hour, the plaster should have set, and the whole thing pops free fromthe bucket, giving you a nice little custom lid for the foundry.

It still needs a vent hole for relieving pressure buildup, and you could just formone when youre casting it, or you could try drilling one with a 3 hole cuttingsaw like this.

With the hole in the center, you can see you end up with a nice thick lid, thatkind of looks like a giant white donut. This design works great for ventingpressure, and gives you the option to melt metal as well, without even havingto take the lid off the furnace.

Step 9: Finishing Touches and First Firing

Pick up a can of Burnished Amber spray paint, and give the foundry a coupleof coatings to make it look a little more attractive.

When you get it fired up, the mini foundry gets so hot on the inside, that it will

melt soda cans within seconds and fill a crucible with liquid aluminum. Look forhow to do that, in another project video.

With this homemade furnace, you have the power to liquify aluminum in thebackyard, and cast just about any object you can think of.

The best part is, when youre not melting scrap metals, rather than taking upspace and looking terrible, you can drop in a plant, and instantly transform it,into fashionable home decor.

Step 10: How To Melt Soda Cans

We have a be nice comment policy. Please be positive and constructive. I Made it! Add Images

2 minutes ago Reply

39 minutes ago Reply

With this transforming Flowerpot Foundry, theres certainly more than meetsthe eye. And by the way, if you run out of soda cans to melt, you could tryusing it as a blacksmithing forge, or even a bbq, for summertime grilling. Afterall, it is fueled by charcoal briquettes.

Well now you know, how to use commonly available materials, to build the minimetal foundry. Powerful enough to melt metal in seconds, but still pleasantenough keep around for decoration.

Well thats it for now. If you liked this project, perhaps youll like some of myothers. Check them out at www.thekingofrandom.com.

dorchard

stephenmack

This is too awesome. I did a lot of metal casting in high school andhave recently found I really miss it. This seems like a great way to getstarted again without spending an arm and a leg. Thanks!

Where could I get an empty fire extinguisher that size? Also, whatsurface is recommended for pouring the aluminum on?

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Ralphxyz

void_main

deadsy void_main

starforest

deadsy starforest

What is the air source?

I hate to ruin everyone's enjoyment (by the way love the instructable)but before trying check this out:

https://www.youtube.com/watch?v=A796N_YZTm8

Commentary-

1) Use tongs that are long enough to get your hands away fromthe heat. Gloves aren't enough. Heat will penetrate thickwelding gloves in time.

2) Don't pour over a flammable or wet surface. When the Alspills (and it will spill) it will set on fire whatever it touches.

3) Make sure your molds are completely dry before you pourinto them. The pop was probably caused by a little steamexplosion. This sends molten metal flying around and that isvery disconcerting.

4) Wear gloves, long pants, boots, a face shield, etc. Coveryour body so that you won't get molten metal on your skin or inyour eyes.

And also:

5) Don't pour over concrete or brick. Even concrete that isapparently dry has moisture in it. When the metal spills on itlittle flakes can explode off leading to the molten metal flyingaround problem.

This is a great idea! But what in the world to do with melted aluminum?

Also wouldn't concert or clay be better and more stable the plaster?

I melt Al and use it to cast parts for small engines that I make.Concrete and Plaster of Paris don't make very goodrefractories because they don't last very long. It works (for afew melts) but the furnace lining will break down. A fire claysand mixture is better- but that will eventually break down aswell. A good furnace can be made from a castable refractorymix (available at your local pottery supply house) E.g. Mizzouor Kast-o-Lite. Some of these are rated up to 3000F so youcan melt brass, bronze even cast iron. To do metals like thatyou typically have to upgrade your burner tech. E.g. Propane or

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void_main

robthebrew

carlos66ba

helbersonr

Safrapath

billbillt Safrapath

offramp billbillt

Oil - not charcoal. Still - this instructable is a nice simple introfurnace- and if you tried it and got into casting then you'dprobably be thinking of ways to upgrade your foundry.

Really nice.

In regards to safety, before trying this at home, please search for "HowNOT to Pour Aluminum Metal" on YouTube. Very sobbering.

http://thekingofrandom.com

Excellent instructable. Thinking of making one myself.

friend he also melts glass ??

I love this. It's a nice simple design, all I'm having trouble with is asuitable crucible. I can't find and old fire extinguisher that's smallenough anywhere!

Also, just so you know your link to www.thekingofrandom.com is nuts,too many https.

Look around for empty propane cylinders used in soldering andcamping.. They seem to be the same thing...

Yeah, that was the first thing I thought, too; I've got a ton ofthem, collected for another purpose, so I can spare one or twoto make this.It also occurred to me that you could use an old 20 gallon BBQgrill propane canister in place of the bucket, here...

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sxcgreekboi_24

AlexT4

JSWheeler AlexT4

Brandon233

ViralFleek

pdu toit1

Mr AbAk

Thissy01

pablofiasco

I watched you melt the alluminium cans last night and was wonderinghow to make one

Whaaaaaat you're on here too?

This is where I found him first haha :)

Cool

is it possible purhcase these in europe?

i run a brozne foundry i think this grate little furnes but not very goodfor anything other than al

Nice and Well described Ible ....

I so need to make one of these... Excellent job!

Would dental plaster work in place of plaster of Paris? I've go 24016-30 lbs of Marlins magic (a hobby brand of dental plaster) just sittinghere doing nothing...m

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alienvibes pablofiasco

Honus

dregalia

pandamopeds13

pandamopeds13 pandamopeds13

peterman921

macktrotter

grunthos macktrotter

Based on knowledge of ceramic mould making and kiln work...check to see if the dental plaster contains any polymers. If itdoesn't then give it a shot.... cast a small quantity of plaster /sand mix in an old tissue roll. Bake it in the over and see if itcracks/crumbles to pieces. The sand is the key element.

Outstanding!

Building this over the weekend. For another project that just kinda fellinto my lap.

Damn! Now thats too cool! Hmm... i may need to make one of these.Been planning to make one of those soup can forges but this has somuch more use. Guess this also means i need to learn how to caststuff. Thanks for the awesome how to man... definitely hitting up thatsight of yours :D

edit: i have been collecting used sodacans and the like to crushand recycle, but reusing them is so much more fun! also thisgives me an excuse to use our fireplace grate and melt downsome plastic bags to reuse in projects.

built one years ago and used fireclay. melted many quarts ofaluminum in a stainless steel crucible. still have it

Awesome!Can this melt copper? I believe the melting point is around 2500degrees...

Copper melts around 1800-2000 degrees F. Yes, this will meltit. But the issue is not really a yes/no question.

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helifino

BeachsideHank

doodlecraft

lilchumy

Tecwyn Twmffat

robbi1

seamster

The real question is: how many times can you melt at thosetemperatures before the plaster refractory starts to crack andcrumble? The short answer is that it will wear out sooner atcopper-melting temperatures than it will at aluminum meltingtemperatures.

The short answer is: try and see. You'll likely have it work fineat least several times, if not dozens. And if you REALLY end updoing it more times than that, you'll figure out a tougherrefractory for the next cheap furnace.

On your second furnace, Mix in fireclay from a pottery supplystore, and fireplace mortar instead of plaster-of-paris, andyou'll get a hobby furnace that will last for many years.

Disliking the recent change in comments, before you could alsocomment per-step.

Step 3, picture 5 has a typo.

Not only are your videos enjoyable, so are the sponsor inserts that areseamlessly integrated and just as engaging. Keep 'em comingHighness, I will pledge my cast from beer can aluminum sword in yourservice as soon as I can down the 150 or so beers needed.

I love it! Great job!

Another great instructable!

Very coool!

nice set up....what did you use for forced air source

We have a be nice comment policy. Please be positive and constructive. I Made it! Add Images

Knocked it completely out of the park, as usual.

So many layers of awesome in this! Just wow.

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