Instructables

Long time fans of blacksmithing, we delighted in having the Florida Artist Blacksmiths Association demo at our recent Gulf Coast MakerCon event in March. We were equally delighted to find a way to bring a little bit of the blacksmith arts into our suburban garage, when we came across this great video by NightHawkinLight, on how to make a Soup Can Forge. Intrigued, we looked around for some written step-by-step instructions and didn't see any, so we hope NightHawkinLight takes it as a compliment that we documented our little build and share it here, as perhaps a companion piece to his terrific how-to video, which we've included here and highly recommend you watch in its entirety first.

Our build time, start to finish: about an hour and a half, mostly 'cause we were klutzy with the fireproof lining mixture.

 
Remove these adsRemove these ads by Signing Up

Step 1: Assemble Your Supplies

Picture of Assemble Your Supplies

You'll need:

  • A can - we used a 28 ounce crushed tomato can, sans the crushed tomatoes. We chose to leave the label on for a Warhol-esque effect.
  • A block of wood
  • A black iron pipe nipple - 1/2" x 2"
  • Two L brackets
  • A pair of wood screws to afix the brackets to the block of wood
  • A pair of small metal screws with washers and nuts to afix the can to the L brackets
  • A small bag of sand
  • A box of plaster of Paris
  • A gallon ziplock bag to mix the sand and plaster
  • A standard propane torch with a spiral flame nozzle
  • Some water
  • Safety glasses
  • Fire Extinguisher - just in case

Step 2: Prepare Can

Drill two holes, about a half inch in from either end of the can.

On the opposite side of the holes, about an inch from the back of the can, drill a 1/2 inch hole for the black iron pipe nipple, at a slightly downward angle.

Step 3: Fasten L Brackets to Wood Block

Picture of Fasten L Brackets to Wood Block

Measure out your brackets against the length of your can and where you drilled your bracket holes in the can.

Step 4: Affix Can to Brackets

Picture of Affix Can to Brackets

Use metal screws with a washer and nut and fasten securely.

Step 5: Attach the Pipe Fitting

Picture of Attach the Pipe Fitting

Just screw it in. It should all look like this.

1-40 of 74Next »

I love it. Great job in the forge and the Instructable. I made one nearly identical to yours before I saw this.

I used a new empty latex paint can and a few pieces of fire proof ceramic blanket for the container. For the heat, I used a torch nozzle like yours. Only I attached it by a hose to a big white propane tank from the BBQ grill.

I got a little fariers anvil and set it up just like yours.

Awesome job.

EurekaFactory (author)  christophor2 days ago
That's a great idea! How's it been working?

How long does the propane last for powering this forge?

Neon_Ivory2 months ago
Thank you, @Amercian Ruin I'll look into it. The sledgehammer is very clever
American Ruin2 months ago

This is awesome. I've been meaning to branch out into metal work, and this is how i'm gonna start!

Neon_Ivory2 months ago
I will definitely look into it. I'm just starting the craft, and planned on making the old "railroad track" alternative. But assuming I can find the baby anvil, I'll likely, go for that. Thanks for the quick response!

Tandy Leather has them... but you can probably find one cheaper with a bit of research. I use the head of a sledgehammer. I had a friend polish and smooth a side at his shop.

Neon_Ivory2 months ago
Where did you GET the anvil?
EurekaFactory (author)  Neon_Ivory2 months ago

We've had the anvil forever, handed down in the family. Further down in the comments somewhere, there's a discussion about it, but the short version of that is that it looks like you can get little 2 lb. anvils like ours in leather working supply shops and other craft shops.

mist42nz5 months ago

what kind of temperature do you think you can get to?
I'd love to have something that could melt copper & brass for amulets.

GregC1 mist42nz4 months ago

no way in hell. built one to see for fun, useless. unless you just want to make some metal kinda hot and not really hot enough to forge anything bigger than a pencil.

EurekaFactory (author)  GregC14 months ago
Small can, small items; bigger can, bigger items. But "for fun" is what it's for. Probably need a more professional arrangement for melting copper and brass, but certainly worth tinkering with to try, I'd say. Really, though - it's just a tomato sauce can with a fireproof lining made of plaster of paris and sand, not a professional forge. It's a proof of concept experiment with some very rudimentary forging capability.
EurekaFactory (author)  mist42nz5 months ago

Hoping someone will have answers for the glass, copper and brass questions - We're curious, too! Just checked over in the Communities section, and in "Answers" and didn't see much on either of these topics, so definitely something worth exploring further.

I'm not sure about glass, but I have plenty of information on metals and their properties regarding casting and forging.

I have done casting, and I can tell you brass and copper both require high temperatures that this type of forge is not capable of achieving. You can melt aluminum and use it for amulets, but it sure won't look like brass or copper.

jscanlan mist42nz5 months ago

Try turning it on end and use a crucible I think that would work

I have made these before and they are a project doomed to futility. The lining will crumble in about 1 to 2 months if you use it with any excessive heat at all.Air pockets will form it after use (it cooks it, and the plaster of paris is actually what crumbles and overheats.)and the chemical composition just falls apart.

EurekaFactory (author)  david.brookes.1864 months ago
Appreciate the insight and experience. But we're not expecting sophisticated, or long term endurance from a spaghetti can forge. It's just a proof-of-concept, fun-to-tinker with project and we've learned a lot from it. It's obviously no substitute for a real forge nor is it intended to be. It's certainly been instructive though!
petawawa4 months ago
Would it work with a 19 0z can?
EurekaFactory (author)  petawawa4 months ago

Sure - but remember the smaller your can the smaller your furnace and the smaller work area you have.

DaveDoesThings made it!4 months ago

Works great! Tomorrow it's time to try a few mods to the interior shape, clean it up a bit, and make myself a spork!

(photo shows first burn, still not hot, was having issues with torch going out because of wind hitting the air holes, fixed, better/hotter now)

IMG_2071.JPG
EurekaFactory (author)  DaveDoesThings4 months ago

Awesome! Congrats!

jscanlan5 months ago

Would refractory mortar.be a better choise? I know plaster of paris and sand is cheap but a better quality material in the chamber might last longer and be easier to work.

it will work better, but it is quite costly. Having experience in casting and forging, I prefer Koawool, a flexible, high resistance insulation for furnaces.

ghost115 months ago
this will be a fun project to make. I've always wanted a forge but they are big and I just want one for fun.

Wow! Now your all set to be a ferrier for shetland ponies.

epicalien5 months ago
I love the tiny anvil
EurekaFactory (author)  epicalien5 months ago

I think we all do. What's not to love about a tiny anvil?! :-)

padbravo5 months ago

Glass?
someone could add info on that?

neffk padbravo5 months ago

Hot work is usually quite involved. I'd take a class on it, to try it out, without having to buy/make a lot of equipment.

eruger padbravo5 months ago

The only glass work that I am familiar with is neon tube-bending I did in art school, and watching the flame workers who make the little ornaments for tourists, but in both cases, a propane flame in the open was plenty hot enough, and anything more elaborate was used to heat a larger area more evenly. So this setup might be perfect if you want long graceful bends, and I think it may be good for blowing small bottles or such. For the very important annealing process that others mention here however, what you need is a kiln that starts out below the temperature where the glass starts to glow and then cools down slowly to room temp, usually overnight. That's usually done with electronic controls or some poor apprentice loosing sleep. People have also accomplished this with an oven and a fire that slowly cools as it burns through its fuel. Without annealing, glass that has been fine for months can practically explode if it's lightly tapped the wrong way.

padbravo eruger5 months ago

hahah! that is a good one! the "poor aprentice"! medieval times?

eruger padbravo5 months ago

You would be amazed at how primitive a lot of glass and metal crafts
still are, even in highly industrialized places! They are also some of
the last bastions of medieval-style apprenticeship! Like a bronze
foundry, where a 1st century roman craftsman would only need a day or
two to catch up with the improvements, and the new guy is still often
unpaid, or may even be paying for the privilege of learning on the job.

I'd say it's possible to get it hot enough for small rod glass, BUT..... You might need a similar annealing oven to slowly harden the object afterwards.. I've melted beer-bottle glass with a propane torch, but it usually shatters if allowed to cool too quickly.

Ah, I get it... if it gets cooled too quickly, it will fragment or something else...
Tks for the info...

They tend to fracture, as if when you put hot water into a cold glass, the inside will remain expanded, but the outside will cool in normal air temp.. and when the cooler outside shrinks, *CRACK!*.. and it tends to go continue right into the inner material. The beer-bottle example, if removed from the fire, and not allowing the fire to die-out around it, the glass will fracture, and split the entire point.. result, broken pieces. (this is why so many suggest using a camp fire, where it'll burn out slowly, but the coals will keep it warm, until they eventually burn out.)

Tks!

Hi! Glass needs to cool down very slowly, drinking glasses are kept in an oven for a full day after forming them. You might want some other form of oven to keep your glass-thingies really warm - maybe a potter's oven you can move into your workshop?

Tks for your answer... I did not know that fact about the "normal" glass on a regular kitchen glass... probably you work on that kind of industry?

Anyway... seems to be that this kind of workmanship uses a lot more patience that I have...

I a more on metalworking, and i wold like to star with molding and molten metal... maybe using this design as basis for a small furnace...
spark master5 months ago

Hi Neffk,

Could he use fire clay sold in Ace hardware etc? Unless you can find Castable refractory (here on LI it is not easily found).

1-40 of 74Next »