DIY Mini Forge




About: Designer and Co-Owner of Krank Empire Design & Printing.. I love to experiment and tinker. Most of all I love meeting other creative makers!

Lately I've been wanting to make some pocket knives for my friends and family.. So, I'm going to make a simple mini forge at TechShop to temper the steel...

This forge is meant to burn coal.. You can you lump charcoal and wood, but it will take a lot more of it to keep the heat at the right temperature for the duration of the process..

Step 1: Things You Will Need..


-- 1 1/4" Scrap Black Iron Pipe..
-- 1/2" Scrap Black Iron Pipe..
-- 1 1/4" Scrap Iron Pipe Tee..
-- 1 1/4 Scrap Iron Pipe Cap..

-- 1/8" Scrap Angle Iron..

-- Small Scrap Plate of 1/8" Steel..

-- 11" Diameter Scrap Brake Drum..

-- Cheap Hairdryer or Other Blowing Device..


-- Horizontal Bandsaw..

-- Cold Saw..

-- Flow Waterjet..

-- Angle Grinder..

-- Lincoln 255xt (MIG)..


Step 2: Waterjet?.. Duh..

We need to plug the five holes in the bottom of the brake drum, and also reduce the diameter of the main hole... Sooo?.. DUH! We're at TechShop, lets waterjet that piece! 

We'll cut a small plate with a 1.27" diameter hole in the center. This plate will allow us to mount the black Iron pipe to the bottom of the brake drum.

Step 3: Choppin' Some Pipe..

Time to start cutting that pipe! we got a forge to build!!!

The length you cut on the pipe is up to you. Just think of how tall you want it to stand. This forge is a little over 3 feet..

-- Cut the 1 1/4" pipe down on the bandsaw so that you have two longer pices and one short piece..

-- Make sure the shorter of the pieces has a threaded end so we can attach a cap to let debris out of the pipe..

-- The longer piece that will be mounted to the brake drum should have a threaded end as well. This will allow the blower arm to pivot..

Step 4: Plug Doz Holes and Mount Some Pipe..

-- Hammer the 1/8" steel plate onto one of the longer pipes that were cut..

-- Grab that brake drum and get it ready for some welding..

-- Position the plate and pipe so the that the pipe opening is in the center of the brake drum hole..

-- Weld the plate and pipe together..

-- Weld that plate to the brake drum.. Crank that MIG and make sure you get good penetration..

Step 5: Tee Time..

-- Thread the tee to the pipe coming from the Brake drum.. Thread it enough so that it's almost all the way tightened, but will still let the blower arm rotate..

-- Weld the blower arm to the tee so that it forms a 90° angle with the pipe coming from the brake drum..

-- Weld the shorter pipe to the bottom of the tee..

-- Thread the end cap on.. This will allow us to release any ash or debris that falls into the pipe.. 

Step 6: Get Your Angle On..

-- Cut down some of the 1/8" angle to make a square on the base of the brake drum..

-- Weld up the little frame on the bottom of the brake drum.. Again make sure you get good penetration on this weld!! This frame will be used to help mount the legs to the brake drum..

Step 7: A Little Mo Choppin'..

-- Cut down that 1/2" pipe on the band saw to the desired height of the forge..

-- Cut down some smaller pieces of pipe to be used as horizontal supports for the legs..

Step 8: Legs and Supports..

-- Cut the ends of 1/2" pipe on the cold saw at a 75° angle.. these ends will be mounted to the frame and brake drum..

-- Weld the legs to the frame and the brake drum.. It's crucial that these are securely welded!

-- Weld some supports for the legs.. this will help with any wobbling..

-- If any of the pieces are uneven.. Cut them down with the angle grinder..

Step 9: We're Blowin' Up..

-- Mount the hair dryer to the blower arm.. I just used duct tape and a slightly larger piece of pipe to mount the blower. I did this because I only want to affix this blower temporarily. I will find a more suitable one in the future..

-- If you use a hair dryer, put a piece of tape over the cool button.. We don't need the blower to blow hot air when the fire will do that for us.. Plus I was worried bout this old thang over heating..

Step 10: Kick the Blower and Spark That Flame..

-- Now you're ready to get that forge burnin'.. I'm not going to get into the details of how to use a forge yet.. I will post another Instructable soon showing you how I temper some of the knives I'm making.. But in the meantime here's a couple shots of it in action..

Indestructibles Contest

First Prize in the
Indestructibles Contest



    • 1 Hour Challenge

      1 Hour Challenge
    • Backyard Contest

      Backyard Contest
    • Frozen Treats Challenge

      Frozen Treats Challenge

    65 Discussions


    6 years ago on Introduction

    I built a similar forge recently completely from recycled and salvaged materials. A welder and angle-grinder were the only tools needed.

    It was pretty neat to go from never having done any blacksmithing before, to building a forge, and starting to work on some metal projects in just one afternoon.

    I had the Bob Rubert  blacksmithing video and made some little twisted coat hooks from old-fashioned square nails. I also tried a railroad-spike knife, which turned out ok. Not as great as I would have loved, but it was the first time I ever tried anything like it!

    2 replies

    Reply 6 years ago on Introduction

    Thats awesome!!
    It really is amazing how easily you can build a forge and get going in one day.
    I can't wait to show y'all the stuff i'll be working on..


    6 years ago on Introduction

    Nice writeup, . Pity I can't get coal around here.
    I think for now I will stick to my smelting furnace when I need high heat.
    But the moment I find some coal, I will come back to this one.
    Saved in my "Future Projects" folder.

    5 replies

    Just thought i would mention making charcoal out of dense timber makes it last longer and burn hotter. If you can find the very base of a stump from a dense old tree and turn that into charcoal it makes a big difference.

    Yes! Or you could use any kind of hardwood lump charcoal. Either way it won't burn as hot as coal and you'll end up using more of it. But in the end the same result can be achieved with charcoal as it can with coal.


    Reply 6 years ago on Introduction

    Yes, good site, but they do not ship to Cyprus.
    And I think it would be way to expensive to ship to here as well.
    Never mind, I will use charcoal.


    Reply 6 years ago on Introduction

    Ah, sorry! I didn't realize where your location was.


    6 years ago on Introduction

    I have a old brake drum forge leftover from the previous lan owners (twenty years ago) it used to run for us but then was neglected for years do you have any ideas for a blower??? besides a blow drier???

    1 reply

    Reply 6 years ago on Introduction

    Sure! Right now I'm actually running a Vacmaster 2.5-Gallon Wet/Dry instead of the hair dryer. I bought it used at a garage sale for 10 bucks! I also will be installing a valve so I can control the air flow. I'll either post the mods I do on this Instructable or make a new one just for the valve install. Let me know how that works out and If you need any other help. Have a great day.


    6 years ago on Introduction

    really like the forge design ive been smithing for a couple of years my forge isnt nearly as well constructed all i used was half a propane tank exaust pipe and concrette the motor is just a air matress pump and i got a rail road track for an anvil

    1 reply

    6 years ago on Introduction

    Just for reference, look up induction furnace or induction forge. That's how modern heating of iron is done. Very clean and energy efficient. No flame though.


    Reply 6 years ago on Introduction

    The heat gun I used during the first run topped out. So, I'm not exactly sure how hot it got. The metal was demagnetized at one point and glowed at a similar color as other metals I've worked with. I was able to hammer it down nicely. And I believe if the right fuel is used, this forge will be great for small projects.