Jump to content
I Forge Iron

Steel wheel JBOD charcoal forge project

Recommended Posts

I have started a simple charcoal forge project because, let's face it, I don't have enough work to do around here!

I thought I would post progress as I go. My research has lead me to a side draft forge for charcoal, and as any container seems to work, I decided to use one of the steel wheels I have stacked about from the boss' Toyota truck.








As you can see from the picture I decided to place the entrance for the tuyere just above the bottom of the container created by the wheel. That would be the central portion of the wheel where the stud holes etc. are located. Marks I placed on the side of the wheel show the interior bottom and 4 inches from the top. The top of the tuyere hole sits just under 5 inches from the top. My measuring tape shows a bit over 6 inches total depth to work with. The width, not shown is 17 and 3/4 inches interior diameter.

Because this is the first forge for me, I have decided not to weld shut all the typical holes in a steel tire in order to hold the rammed earth I'll be using, Instead I found an old plow disc that fits inside, and with a few river rocks, I think I have closed up the bottom for the addition of my local dirt. When the time comes I should be able to just knock everything out and start over.

Here is the pipe, subfloor and stones in place.



I will be sizing the fire pot 4 inches wide, 8 inches long and about 4 inches deep. Here is a pic of a 4x8 brick for relative location. I will not be using any brick below hearth level. This one is just in here to help me visualize the volume of my fire pot. 


It seems I won't have a large amount of real estate on the surface, but I will have plenty of room for the mounds or bricks at hearth level to contain the charcoal.

I'm anticipating needing to enlarge the hole to raise the tuyere and thus the fire pot. We shall see what we shall see.


Taylor, near Jeddo TX

Link to comment
Share on other sites

Make sure, whatever happens, those rocks don't get close to the fire, about 230f and they'll begin to give up their hygroscopic moisture which can be rather ugly if you're within shrapnel range. Steam explosions can be wicked powerful even in small packages.

I strongly suggest you find something else and lose the RIVER:o rocks. 

Frosty The Lucky.

Link to comment
Share on other sites

Been there done that!  When I was in Scouts I got a brand new air mattress for Christmas. The first campout I was using it; some doofus used a crinoidal limestone for the fire ring and a rock blew up and melted a hole through my brand new, unused air mattress a dozen feet away.  Luckily no people were hurt but it was a a hard bed that night!

So 30 to 40 years later when we were cooking meat in a hollowed out log using heated rocks; I made a fuss about it and was assigned the job of sourcing "fire safe" rocks and testing them before we used them at a public demo.  (Mafic seemed to work the best of what I could find---geo degree!).  Worked well and the roast was excellent boiled in a tree trunk.

BTW your design looks like a bottom draft forge with the tuyere just coming in to the center ontop of the bottom of the forge instead of underneath.  Needs to be raised if you want a side draft!

Link to comment
Share on other sites

Quite right, Frosty. I was being lazy. Here are some pics.


I re cut the hole so that the bottom of the hole was at my 4 inch mark. Now, to allow the pipe to have a slight rise into the forge, I should have placed the hole a bit lower, but I was not up for doing that math. Anyway, I'm not allowed, I'm an English major. In some posting I found a suggestion that the tuyere could be sloped up about 5 degrees. A little bit of searching yielded 5 deg equals 1":12". So a series of side picks showing what various pitches would look.

I settled on a piece of 3 inch brick under the inside edge of pipe. This gives me a 5 deg. slope to the tuyere. If this is not necessary, for goodness sake, don't tell me.




Finally, rocks out, pieces of low duty firebrick in. I'm about to go collect dirt which seems to be about 95% clay with very little sand or stones. This I will dry pack.


Feel free to keep the comments coming.

T near Jeddo TX


Link to comment
Share on other sites

Picture to aid in my firepot shape question:


I have drawn some lines on these bricks to get an idea for the bowl or pot shape. These bricks are sitting on the current level of soil. Note the 4 inch depth line spot on the hearth guide I placed along the right side. I have seen bricks forming the pot, making it a rectangle with square section. I have read that the long sides should stay somewhat vertical and the shorter ends slope towards the tuyere to allow the charcoal to stay centered. I would love to know what to shoot for. A 45 deg. angle brings the slope just under the pipe. A 65 deg. (guess) brings the slope down to a 4 inch square floor centered on the tuyere.

Link to comment
Share on other sites

15 hours ago, Irondragon ForgeClay Works said:

have always understood the tuyere should be sloped downward not up.

I think five degrees is the approximate sweet spot. It'll move the fireball away from the wall slightly. 


Link to comment
Share on other sites

Packed local soil around tuyere and some bricks. This stuff is very very picky. Either it is hard as stone or it is slippery and sticky, very little in between. I'll think about a tempered skim coat when I pull the bricks and slope the ends of the fire pot.








half filled. Piece of brick will hold the pipe at level.









Tuyere is now covered and bricks placed to reserve space for fire pot.








Done, top screed and spritzed with water.

I'll let things dry a bit before I knock out the bricks and finish forming the pot.


Link to comment
Share on other sites

Oh don't I know it. It is normal for me to see 1 inch cracks in my yard deep enough to put my hand. The traditional method of countering excessive shrinkage is to temper with a non-shrinking ingredient like sand, organic material, grog, or even calcined material. In my research I have not found a problem with any of those tempers (organic stuff might not be a good fit) if the fuel is only charcoal. Someone correct me if I'm wrong.

Now I have always used grog made from fired earthenware, smashed up IFBs, or calcined kaoline in my other work, but I don't want to use that stuff just yet. Let's see how this first go turns out. I can tell you that consolidating this packed earth is both easy and a pain at the same time: too much water and it will shrink horribly, too little and it stays crumbly. I have to hit the sweet spot with the moisture.

Might be able to put some fire to it today. Will post pics if anything interesting happens.

T near J TX

Link to comment
Share on other sites

No, you're not wrong. Sand in the mix provides two important things, first a little movement so the material can dry without checking, secondly a way for moisture to escape. Sand is second on the list in a forge as it will fuse and stick to hot steel, it makes clinker. Grog would be much better but a charcoal forge fire will melt it too but depending it may not be so sticky when molten. 

We have a source of river sand here that isn't a silicate, pegmatite I think but could be wrong anyway it doesn't vitrify so easily and works a treat as aggregate when claying a forge pan. I found out about it from the club member who is a caster and uses it for his petrobond casting sand. He makes regular collecting runs with his students. 

Might be worth picking up a copy of "Roadside Geology" for your area and maybe seeing what's available online, USGS has more info than most folk could ever use, some from surveys hundreds of years old. It's a neat site to browse if geology's your thing.

Frosty The Lucky.

Link to comment
Share on other sites

I know I should be changing the oil in the wife's truck, but I needed to see some fire. It's been so long.







So I wheeled the HEAVY steel tire charcoal jabod forge to the edge of the driveway slab, under a nice post oak. I split up some pine construction waste I keep for starting the wood stove, and crisscrossed the wood in the firepot. I found my trusty propane torch I use to dry pots while throwing and lit the wood. Good so far?







I fiddled with a small fan and a funnel to see if I could provide enough tuyere air to get that wood hot so I could throw some big box store lump charcoal on top. Boo, didn't work and the wood was now charcoal itself. Pulled out my air hose, put walnut sized pieces of charcoal in the pot, and fired up the torch once again. That worked. Some sparks flew about until I found the touch with the air tool, then a nice low roar and much sooner than I thought, I had orange to yellow heat. I think it's going to work, ladies and gentlemen. Now I need to figure a way to hold it up at working height, sort out the air supply, and pull my anvil up close.



Taylor near J TX

Link to comment
Share on other sites

Indeed. I have read in several threads about the size of charcoal for forging, and I had walnut sized chunks for the most part.

Fired it for a second time with just the air compressor  with a stick blower. I have learned quite a lot of things in that three hours.

  • I burned perhaps a third of the bag of charcoal in three hours.
  •  I could get a very nice bright orange which I thought was a bit too cool, but I was able to move steel.
  • Worked my very first taper which turned out meh. In the process I confirmed that...
  • my anvil edges are still too sharp. I will need to grind them with a wider radius at least on one of the two sides.
  • I learned my anvil can indeed be dented by my hammer after two errant blows on the edge.
  • That orange I talked about which was perhaps too cold. Well, I pulled out a nice start to a coal rake to see how glossy that orange was and oh look a drip. 
  • AARG! I can burn scrap rebar in this forge in mere seconds.

All this working today was on scrap rebar, never intended to keep. I just needed to make my first swings on some hot metal. I enjoyed it and will do much better I'm sure.



Link to comment
Share on other sites

Have just come running back inside after scampering to put, anvil, tools, and JOBOD forge undercover! We have a gully-washer for sure.

I had gone back outside after posting my last to try my hand at a better rake for the forge and was able to restart new charcoal just from the residual heat of the firebox. I had scraped out most all of the charcoal and let it cool on the top of the forge.

Other things I have learned


  Rebar fire tool practice along with junk from the firepot.










  • The forge stays hot for a very long time, so a plate cover is in order
  • I was able to reduce my charcoal usage by allowing the mound to drop below the level of the bricks sitting on the hearth.
  • When I uncovered the fire, I saw what I thought was the heart of the fire well below the level of the hearth, so I don't know what a charcoal forge fire should look like.
  • While charcoal is not supposed to form clinker on its own, I fished out pieces of the packed soil, slagged by the heat. My soil is definitely a terra cotta. The clinker is classic over fired student earthenware.
  • I have a long way to go
Link to comment
Share on other sites

Charcoal continues to burn even without air blast. One way to conserve is to sprinkle it with water when done forging. I use a water sprinkler can like this one I made out of an empty O2 cylinder with an old fire tool handle and holes drilled in the bottom. Works well with coal/coke too. I scoop water out of the slack tub.



Link to comment
Share on other sites

Charcoal doesn't produce clinker all by itself like coal can. However whatever falls into the fire or is close to the heart and can melt sure can become clinker. Finding part of the clay packing of the forge turned into clinker is pretty normal.

Frosty The Lucky.

Link to comment
Share on other sites

I did fish out some small pieces of limestone. That must be where they came from.

The initial JABOD was fun,  but I'm in it for the long haul and my packed soil was too easily melted.  I have upgraded the firepot with IFB 28s. This will stabilize the pot's dimension while i learn the basics of fire management and forging. 









After about only 5 hours of firing.









Insulating fire bricks taking the place of the soil at the fire pot.









Fire pot finished. Sloping sides to feed the charcoal down to the tuyere. Approx. 8 inches long at the top, 4 inches wide.









Depth is about 4.5 inches, the width of these brick.


Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Create New...