Charles R. Stevens

Just a box of dirt, or a simple side blast forge

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Chelonian,

If you haven't yet, read the Mark III jabod thread. Define the fire bowl with bricks and use loose fill around them. I used plain dirt. This gives you flexibility to change bowl size as you figure out what works best for you. Then go with a more rigid design. Personally I like the flexibility.

Laynne

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Thanks everyone!

Laynne, I had not seen that, and I think that might be what I try first actually! I have a ton of those red bricks from when we got our old chimney rebuilt. Also, I'm assuming I should avoid using a galvanized pipe as the air pipe? or does it not get hot enough to be a problem?

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No galvanized pipe.  If you can use vinegar or stronger acid to remove the zinc first then you can use it.

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If you have a bunch of clay bricks a JAPOB forge works just fine. Lay yourself a 2” table of bricks now depending on what you need eithe lay a cuple more layersleaving a single or double  brick sized hole 4” deep 4” wide and 8” long or 8x8 and 4 deep. You can build a single wall to bank fuel against or a pair. This helps keep the fuel in an effecent pile. Unlike coal fire spree is a real issue with charcoal so you can’t just put more fuel on the table to make a mound around the hotspot. 

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If you are in a wet area you may want to "proof" your bricks first in a fire you are not standing right by in case there are any steam issues.

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Currently de-galvanizing a pipe in vinegar and trying different layouts of bricks in the barbeque to see what seems best. The bricks do seem rather wet, so I think I'll just keep the top of the barbeque on loosely for the first time I use it.

Thanks!

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You could also put the bricks in the oven set at 200°F (or a bit less) for a couple of hours, to help drive off any moisture.

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I've been mining gold info out of this thread so thank you to all who contributed. Here's what Charles said that I cut, reorganized, and pasted:

////////JABOD Forge

Extra thanks to Charles R. Stevens for forge details and experimenting.

Dig a straight sided trench, 4" wide and 8-12" long.

The tuyere comes in the side of the trench.

The long sides of the trench slope down to the tuyere making it easy to clean and encouraging fuel to settle down.

You would have 2" of dirt between the fire and the bottom and an inch under the tuyere.

You want at least 3-4" above the top of the tuyere to the top of the table.

Now at this point either use bricks or make mounds of dirt on the long sides of the trench up to about 4" to keep the fuel over the stock from running off. Banking coal works, but with charcol you just end up with all the fuel on fire, and still only get 6" of hot spot .

So with charcoal and a 3/4-1” tuyere I find a 4x8” trench about 3” deep to the top of the tuyere good. That makes the trench from 4-5” deep. (5” gives space for coal slag to collect).  With charcoal you need somthing to bank the fuel pile above the hearth (and over the fuel against) so you need a 4” bank on on or both sides of the trench.

With coal you can bank against more coal, and a 6-8” round bowl works well but as I like the multi fuel aspect I use the trench for both.It also holds just a little bit less fuel, the sides make holding the fuel in place easier and it reflects the heat. 

The trench is easy to clean and seems to give a better fire over all.

Down side of the double walls is that scrolls don’t fit well. Single wall works well and one can always grab a brick.//////// 

I know it's not perfect but it's what I have for now......may add in the future. I look forward to finishing my forge and will show y'all when it's done!

 

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Hi. Those are really cool projects! I want to make my own, but I don't have any clay. Concrete is a pausible sustitute for it, after a few days of drying? Or it's insecure?

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Concrete can spall or degrade at forge temps.  If We only knew where you were at in the world We could suggest something local!

Here in the USA you can buy clay cheap sold as "bottom of the line" cat litter or  as oil dry---check the label first!

If you lived in Columbus OH I could talk you through getting to the clay bed in a creek, if you lived in Central NM, the clay plates in the Arroyo after a flood dries are easily found.

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Actually, I'm from Mendoza, Argentina. We have limited options here, but I'll try to find any of the options that you gave me. 

Sorry if my english is bad, I speak Spanish! Thank you for your help!

 

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A curious fact: In Spanish, we use two different words for "Forge". The Forge where you burn fuel, it's called "Fragua", and the Forge process it's called "Forja". 

Thank you again for your advice. 

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Interesting. Thanks for the info.

And since I didn't say so before, Welcome to IFI! If you haven't yet, please READ THIS FIRST!!!

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Nico, if you're looking for clay, bentonite clay gets used in a number of applications:

  • Well Drilling
  • Pond lining
  • Livestock Feed additions
  • Wine Clarification
  • Ceramics (Pottery)
  • As noted: Cat Litter, or any other cleanup application that calls for clumping-up spilled stuff

While your options may be limited where you are, one of those applications is bound to be in your general vicinity, it's just a matter of talking to the right person to get access to a supply.

All that being said, as JHCC stated, 'Any dirt will do'.

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Welcome aboard Nico, glad to have you. You don't need nor want anything special in a JABOD if the soil will pack hard when most it's perfect. When you make the JABOD don't make mud and trowel it in, just make it damp and ram it with a mallet, end of a board, etc. 

Frosty The Lucky.

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Nico, any soil that makes good Adobe will work. I used clay because that is what came out of the post holes for my pole barn. 

Ceent not only spaleds but will break down at forging heat. A pile of red brick or fired adobe will work as well as just a box of coal ash and clinker (standard for side blast forges in England). 

The Spanish missions brought large horned post anvils and constintina bellows to South America 

 

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Thanks to all. It's a lot easier than I expected. Our soil is mostly sand, because Mendoza is kinda like a desert. Maybe I can found some good clayey soil near a river. 

Bentonite is easy to find in hardware stores, I didn't know that is a good material. I'll try to get some. We use it here for wine clarification (I have used it, winemaking is one of my hobbies). 

As you can see, I'm a newbie in blacksmithing (not only in the forum). It seems that blacksmithing community is really kind! Another reason to dive into this new world. 

On 1/30/2019 at 5:28 PM, JHCC said:

Interesting. Thanks for the info. And since I didn't say so before, Welcome to IFI! If you haven't yet, please READ THIS FIRST!!!

Thank you, I'll read it right now. 

Nico 

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8 hours ago, Nico M said:

 seems that blacksmithing community is really kind! Another reason to dive into this new world.

Stick around, even if you just lerk. You can learn A LOT from these folks. I have in the past few months.

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You'll want to mix bentonite with sand or it'll do strange things as it dries. About 3 pts sand to 1 pt. bentonite will still be plastic if you get it too wet but shouldn't shrink check much as it dries. Tempering bentonite is a little trickier than garden or ditch clays. I like to wet the sand and mix it into the bentonite so it's fairly evenly mixed. Then put it in a sealed bucket or plastic bag and let it rest over night so the moisture will disperse evenly then test. Squeeze a handful if it makes a hard clump that breaks evenly it's just right. If it crumbles add a LITTLE water mix, let temper over night and test again. If it leaves a mud smear on your hand it's too moist add a little dry material, mix, temper and test.

That's a little more "just right" than you need for a forge, it's the technique you use to temper "sand" for green sand casting but it works a treat for claying a pan forge or for most anything you need good hard clay. Too wet and it will crack as it dries like a pond does.

Frosty The Lucky.

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Right now I'm letting 50 pounds of Raku clay temper, so I can clay the new side blast charcoal forge I'm building. Raku clay has a lot of grog in it so should work OK. We bought the clay back when my wife was doing pottery maybe 20 years ago and it was hard as a brick. Put about a cup of water in the plastic bag with the clay a couple of weeks ago and it's ready to cut and install if the weather ever warms up.

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Ok here's the coal forge I made using the guidelinesIMG_20190202_133519.thumb.jpg.e95b62071d25cab650a02cbb95cbe614.jpgThe blast is near the bottom.IMG_20190202_133631.thumb.jpg.3cedce68bb323ae294557fb3e39d2b5c.jpg Here it is after an unsuccessful forging attempt this morning. IMG_20190302_120347.thumb.jpg.6651cf238b83cfce9e485c966ef491f6.jpgIMG_20190302_120352.thumb.jpg.2502824e48e984c4e747884da23620e9.jpgThere was a fireball in the trough and the coal was piled up a few inches. The metal was a 3 ft pipe that I laid parallel to the table surface. It just wouldn't heat the pipe much. How do I make a useful fire in it w/ coal. Does the fireball have to be huge or what's the minimum size? Should I make a cave or trough? 

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Air moves threw the pipe, thus cooling the area in the fire and heating the end your trying to hold. 

Now coal behaves just a little different than charcoal. First it likes a bed about an inch deeper  than charcoal. So about 4” aboove the tuyere. Second you need 4” above the hearth. Soft coal sill clump but not hard coal. 

So tell me what kind of coal, size if tuyere, deepth below the hearth and air supply? 

I heated the eye of a pick with hard coal and drifted a large pin threw it to make a tin stake so i know it will get hot enugh with the set up I used

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Charles the tuyere is 3/4" diameter, it's 3 1/2"below the hearth and I'm using bituminous stoked coal.

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