The Mini Steel Bucket Foundry.





Introduction: The Mini Steel Bucket Foundry.

I have been corrected as I used the incorrect terminology for this device.

Forge: a place where objects are made by heating and shaping metal.

Foundry: a workshop or factory for casting molten metal.

This foundry is used to melt metal, it can reach up to 1500°f possibly more and at this temperature we could melt brass and copper. but I'll be starting with aluminum.

The hardest item to find for me was the fire clay, and so my advice to you guys is to start with finding the clay, where ever you buy the clay you should find Silica sand.

"Two birds with one stone" is how it goes right.

Most the other items can be salvaged or easily found at a few local stores. The Stores that I visited here in Phoenix Arizona were the Marvel Stone and Brick, Home depot, & Good Will.


1). @ Marvel.
Fire Clay. $20
Silica sand. $20

2). @ Home Depot.
Portland cement. $10
Perilight. $ 5
Steel bucket. $10
Lid bucket. $ 2
Mold bucket. $ 3
Steel forces air pipe. $ 8
PVC forces air parts. $ 7

3). @ Goodwill.
Adjustable blower. $ 3
Med sized muffin tray. $ 2
Heavy Steel crucible $5
(preferably 3-6mm).

Steel tongs. free

***optional*** items are:
charcoal (fuel the forge), play sand (casting stuff) , Styrofoam (casting stuff), Hi-temp paste coat the inside of the forge.

Tools required are
- Corded Reciprocating saw with a metal blade.

- Cordless drill with a mixing paddle & a 1 1/2" hole saw.

- Razor blade knife & or soldering iron.

- Roll of tape.

- mixing tool

*This plan is from "The King of Random*

Step 1: The Preperations.

A few items need to be modified to allow them to work with our setup.

The first mod is to cut an angle in the 8" steel forced air tube for a flush connection to the inner chamber of the forge. there is a method for a really good contour but this is quicker and the perfect curvature is unnecessary.

Another is modifying your stainless steel container to create a crucible. I used a drinking bottle hopefully it is not to thin. (which it did and the next one and the next one went through a total of 5 thin steel crucibles).

lastly we will need to prepare the refractory mix, measure out the 7 parts into separate containers.
1.5 parts Portland cement. 2 parts Silica sand. 1.5 parts perilight. 2 parts fire clay.

Step 2: Mixing and Casting the Refractory.

To mix the correct amount we gotta do a little math to do so this is what I did there is probably a better way out there if comment away otherwise I'll explain.

1.5 parts Portland cement. 2 parts Silica sand. 1.5 parts perilight. 2 parts fire clay.

Start by subtracting the inner chamber casting container (eg. 2.5 qt HDX translucent bucket I used) from the outer shell bucket (In my case the 10qt steel bucket)= 7.5qt the lid is the same story but no subtraction unless u cast a feed hole, "I digress".
add 5 qts for the lid (i. my case the blue bucket) 12.5qts now you gotta figure per parts and what not, anyways I got it wrong, even tho I measured for the lid I only had enough for the forge, so clearly my math needs some help, but the point is to divide the total quantity A/B by 7parts and find out the total for 1.5 parts and 2 parts.

(The easier way is just use a cup and count out the each one).

Store your measurements into 4 separate containers. Then when all your tools have been prepared and the water sprayer is loaded add the first three ingredients and give it a good mixing until all ingredients are blended evenly. once blended slowly add water by spraying and mixing. Once damp add the last ingredient the clay and add more water till you get a dough like consistency. Now we are ready to cast.

Start by adding the mixture and packing down each time to ensure no bubbles, when about half way slowly and steadily push the inner chamber bucket into the center allowing mixture to squeeze up the side Finnish adding the mixture and clean off the top if some is left ove you can cast the lid of your foundry.

To make the lid I used the blue measuring bucket as a mold by add all the refractory inside then quickly flipping it over and slamming it down on to a surface where it can stay to set up but before it does I shaped it with may hands and cut a cone shape with a plastic drinking cupfor the feed hole the cone shape stops the lid from falling inside.

this design didn't last at all unfortunately it was way to thin I have since made another by Gmail sing a lot more refractory and leaving it to set in the mold.

Step 3: Firing the Forge and Setting Refractory Cast.

Once it has set and hardened you can use the hole saw in the drill to cut a 1 1/2 " hole into the bucket as to enter the inner chamber at an angle. insert the steel connector tube and attach the blower. Now we can light it up and fire the clay.

This is another critical step that will result in injury and or death if not done correctly. Steam is very powerful and when forced into a small space and heated will expand and rupture its cavity causing an explosion.

To avoid this we take time to dry the casting by leaving it to air dry for 3 to 4 days under a plastic cover, this helps ensure an equal dry throughout the casting after 3.5 days we can fire the casting.

start off at a very low temperature by burning a small amount of coal adding more every so often to keep the fire burning we want to keep it cooking adding more coal and turning the blower on and off keep adding coal to fill the chamber. once coals have diminished refill and turn blower to hi through this time you should be able to smell the cement moister in the air.

Step 4: Lets Melt Some Metal.

this is quiet a dangerous step long jeans longs sleeves closed toed shoes welding gloves a face shield this is the essential gear for this step any thing less is just plain dangerous. so continue with caution.

slowly adding all the aluminum cans and scrap metal will create slag on top of the liquid aluminum this needs to be removed I used my tongs and this worked fine once there is a substantial amount of molten aluminum we can pour it into our muffin tin at cast our ingots.
here is a video.



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    Have you noticed any ill effects from using Perlite that's enriched with Miracle Grow? I'm also building a foundry, but I've been hesitant to use a product with plant food chemicals in it because of what might happen to them at temperature...

    4 replies

    have not noticed any immediate issues with using miracel gro perilight although my refractory is cracking not sure if this has anything to do with it.

    Probably is moisture related rather than plant food related... I was more worried about the fumes from burning Miracle Grow, I hadn't thought about it causing weakness in a refractory mix.

    I'm working on my own foundry at the moment, and I think I'll cut up some fiberglass mat and toss the fibers in the mix to see if that does anything about contraction and cracking. I'll let you know what I find out when I get around to the project.

    sounds good some ideas I've heard are sawdust it burns out after being fired and Styrofoam does the same causing lots of air pockets after firing.

    If you're worried about fumes, just do a few high temp burns in a well ventilated area/outside to burn off any miracle grow residue.

    Great Job!!

    As a note. As you start casting more you'll find the yield of melting cans to faffing about is pretty unfavorable. Also cans are formulated to be extruded not cast which doesn't make a big difference until you start casting for a purpose. A recommendation for anyone playing with this is to find your local auto-junkyard to hunt for scrap Al. In exchange for a few nifty castings I had the owner of one keeping an eye out for wrecks or car fires that had damaged the aluminum parts. Worthless to his parts business but at a price better than scrap and a few knickknacks ( I think I cast him new knobs for his bbq along with a few other things over a couple beers one weekend) I had more prime casting Aluminum than I knew what to do with. If it's too big to fit in your crucible start a fire in a fire pit or a grill that you don't ever plan to eat food in again. Heat the chunks up, then just wack it with a sledge hammer. This should make short work of breaking even cylinder heads down to size. WEAR PROTECTIVE GEAR. Flying quasi molten aluminum isn't a joke and can really mess you up.

    Keep at it. Metal casting is one of the most fun, addicting, and useful hobbies. If you want something fun and challenging look at the "Gingerly Machine Shop from Scratch" series out there where you build a lathe and mill from a small aluminum foundry like what your have here and some basic hand tools.

    If you start hearing the word cupola and salivating you in too deep and there is no help but to upgrade to casting iron. Just don't wander off with all the wife's cast iron as "casting supplies"... They just don't appreciate the struggle.

    1 reply

    thanks, lots of sound advice to work with here.

    A few people have commented on Grant Thompson's (The King of Random) version of this project that the drinking cup crucible does indeed fail with any sort of load. Crucibles are sold online or you can weld some heavy steel plate onto a thick steel pipe. Do not use the drinking cup method! Or if you do, stay well out of its range while using.

    2 replies

    indeed the drinking cup failed after about 12 hrs of use.

    Agreed. And to be honest you can get an actual crucible for like 15 dollars 30oz it's and that's about the same price as a metal drinking canteen. So safety first everyone.

    This is a foundry, not a forge. A foundry is made for the purpose of melting metal, while a forge is made for heating metal up for the purpose of shaping.

    2 replies

    It's a furnace, not a forge or foundry.

    Yep, Mark's right it's a Furnace by definition a foundry is a workshop not the device. Foundries are workshops that cast metals into shapes parts etc. They would use furnaces inside it. But generally you could call this a "portable foundry furnace"

    any difference between this and a foundery? No insult meant just want to know wether the terms are interchangable or I have to build both or

    1 reply

    I like how you bologna cut the forced air pipe and put it in at a slight angle to create a vortex inside. I also like the use of the travel dryer, as it won't over-power the lot. I'd add a few adjustable Venturi ports and say you've got a good setup. I've seen the KOA version, and I like this better. Borrowing from both, as we all almost always do, will yield best results.

    Grant Thompson used an old fire extinguisher with the top cut off as the crucible, much heavier steel than the drinking bottle.

    I kind of wish you'd shown how you cast the lid, as well.....

    My guess is that your crucible is going to oxidize really fast with how thin it is. Hopefully it doesn't catastrophically fail with a load in it.

    Just so you know, soda cans tend to kick off a lot of dross when melted and have a lot of waste as a result. Broken aluminum castings or old aluminum lawnmower engine bodies are a better bet for a good alloy that will have a lower amount of waste.

    Good to know thanks for the correction.