you’re looking at, is actually an artfully disguised, metal melting furnace. In this

project we’re using equal parts of sand and plaster, to make a simple backyard foundry,

that’s powerful enough to melt scrap metal in seconds, but still pleasant enough keep

around for decoration.

Let’s start this project with a big bag of play sand, and some plaster of paris. Both

of which you can find at your local hardware store, for under $20. We’re also gonna

need a 10 quart steel bucket, and a tablecloth to cover anything important, because chances

are this is going to get a bit messy. I found that this 2.5 quart bucket can be used for

measuring the ingredients, but it’ll also serves a more important purpose that you’ll

see in just a second. Now the recipe I’m using for this makeshift refractory lining,

is 1-3/4 buckets full (21 cups) of plaster of paris, 1-3/4 buckets full (21 cups) of

sand. And 1-1/4 buckets, filled (15 cups) with water. The moment the water touches the

dry mix, the clock starts ticking and we’ve only got about 15 minutes before it all hardens

up. So let’s get busy mixing everything together. It’s really important to get all

the dry powder wet, and work out any lumps as quickly as possible. And after mixing for

a couple of minutes, it should be fairly runny, and roughly all the same color. Now when you’re

convinced there aren’t any clumps of powder left in the bucket, the refractory mix is

ready for pouring. So let’s carefully transfer it to the steel bucket as slowly as practical,

to minimize the splattering. There should be just enough fluid to fill the bucket about

3” from the top, and now if we bring back our plastic measuring bucket, we can use it

to form the center of the foundry. I filled my bucket with water, to give it a bit of

weight, but anything like sand or rocks will work as well. And you can see that as we push

the bucket into the center, the mixture rises upward, but it doesn’t spill out. Now it’s

obvious that the mix is already starting to firm up, so let’s try working the bucket

up and down a few times, to help level it before it sets. And all we have to do now,

is hold still for 2 to 3 minutes. This will give the plaster just enough time to harden,

so the bucket stays in place,even when we let go. Alright, time for a little cleanup.

Everything will still need about an hour to really harden up, but the plaster’s still

soft enough that we can clean and shape it to look really good. And while we’re here

we may as well wipe the bucket down as well. Now I’ve found that if we dampen a rag and

gently drag it around the top, the surface cleans up really nicely, and gets a cool texture

in the process. When it looks the way you want it too, simply leave it for about an

hour. Now while we’re waiting, why don’t we turn this old steel fire extinguisher,

into a custom crucible. You can tell it’s made from steel because when we hold a magnet

to it, it sticks. And magnets won’t do that to aluminum. I depressurized the tank and

unscrewed the valve from the top, to make it safe and easy to cut in half with a hacksaw.

Which you can see just happened in less than a minute. Now the bottom part of the extinguisher

is what we want for the crucible, because it’s basically a steel cup 3” in diameter,

and 5” tall. That’s going to be perfect for our custom backyard foundry. At this point,

the plaster should be pretty well set, so let’s dump the water from the bucket, then

use something like a pair of channel locks, to grip one edge of the pail, and pull gently

toward the center. Now if we grip it with both hands and give it a bit of a twist, you

can see the whole bucket pops loose, and pulls right out. This just created an amazingly

smooth surface, which gives this makeshift foundry, a surprisingly professional look.

The only features we’re missing now, are an air supply port, and a lid, so let’s

make those next. Now I found a 1-3/8” (35mm) hole saw was the perfect size for accomodating

this 1” steel tubing, and if we center the metal cutting blade with the top line on the

bucket, we can carefully begin cutting through the metal wall. Once we’re through the metal,

it’s easy to burrow down at about a 30º angle because the plaster hasn’t fully cured yet,

and cuts away like butter. Now we have a tight, downward sloping hole, that the blower tube

fits perfectly into, and it’s strategically placed, a few inches up from the bottom. This

way, if a crucible fails, and dumps molten metal into the foundry, it will stay in the

foundry, instead of dangerously flowing out of the pipe. Now the blower tube is really

easy to make, and starts with a 1” steel pipe like this. This is the “business end”

that'll sit next to the hot coals in the foundry. We’re also going to need a 1" PVC

coupling (Slip x FIPT), as well as some 1” PVC pipe. You can see the threads on one half of

the coupling screw onto the steel pipe, and the slip adaptor on the other end, simply

pushes onto the PVC tube. It’s that easy. Now let’s go one step further and make a

lid to help retain the heat. I got a couple of 4” U-bolts from the hardware store and

stood them upright in a 5 quart, bigmouth bucket, filled with a half-measure of our

insulating mix. (10 cups plaster, 10 cups sand ,7 cups water). After an hour, you can

see the plaster has set, and the whole thing pops free from the bucket, giving us a nice

little custom lid for the foundry. It still needs a vent hole for relieving pressure buildup,

and you could just form one when you’re casting it, or you could try drilling one

with a 3” hole cutting saw like this. With the hole in the center, you can see we end

up with a nice thick lid, that kind of looks like a giant white donut. This design works

great for venting pressure, and gives us the option to melt metal as well, without even

having to take the lid off the furnace. Just for fun, I picked up a can of “Burnished

Amber” spray paint, and gave the foundry a couple of coatings to make it look a little

more attractive. If we get it fired up, you can see 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 for how to do that, in another project video. With this homemade furnace, we have

the power to liquify aluminum in the backyard, and cast just about any object we can think

of. The best part is, when you’re not melting scrap metals, rather than taking up space

and looking terrible, you can drop in a plant, and instantly transform it, into fashionable

home decor. With this transforming “Flowerpot Foundry”, there’s certainly “more than

meets the eye”. And by the way, if you run out of soda cans to melt, you could try using

it as a blacksmithing forge, or even a bbq, for summertime grilling. After all, it is

fueled by charcoal briquettes. Well now you know, how to use commonly available materials,

to build the mini metal foundry. Powerful enough to melt metal in seconds, but still

pleasant enough keep around for decoration. Well that’s it for now. If you liked this

project, perhaps you’ll like some of my others. Check them out at www.thekingofrandom.com.