Charles R. Stevens

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

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On 8/13/2017 at 4:28 PM, Charles R. Stevens said:

Then you will love the pump

I don't doubt it... until it gets here though... *puffs out his cheeks* ...

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I have  not stopped my experiments, and now recommend a trench, insted of a bowl. Put the tuyere in the side of the trench, taper the ends to make fuel additions and cleaning easer. If you make it 4" wide then standard hard firebrick works well for extending the trench above the table (ground) one brick or no brick depending on what you are trying to heat. Because of the low mas, fuel effecency is a must with charcoal. 

Something like that

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I just showed this design to my friend and half way through the pics he was already looking for his shovel :D

I have some difficulty picturing the trench setup in my mind, any pics about it? How do you position the tuyere?

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The tuyere comes in the side of the trench, but instead of a bowl 8" across, instead dig a strate sided trench, 4" wide and 8-12" long. The long sides of the trench slope down to the tuyere making it easy to clean and encouraging fuel to settle down. 

So, let's cover it again, you want atleast 3" between the floor of the box and the bottom of the tuyere, and 3-4" above the top of the tuyere to the too of the table. You would have 2" of dirt between the fire and the bottom and an inch under the tuyere 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 . 

 

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Purgatory Ironworks (a smith from Georgia named Trent) is currently doing a series of videos for starting blacksmiths.  His last couple have covered these types of forges.  He gives pros and cons and draws out how to design them.  His knowledge of the JABOD is not as profound as Charles' but the videos are informative nonetheless.  He also communicates the IFI stance on anvils and the benefits of big chunks of steel over hunting for "real" anvils.

If visuals help you check out his videos.  Picture Charles' trench as a capital "T" shape.  The air pipe (tuyere) is the bottom line connecting to the trench which is the cross line at the top of the "t".

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On 8/13/2017 at 0:26 PM, NomenCallide said:

Yeah I use a blow pipe... it is a pain in the rear but it works

If your blow pipe is a pain in the rear you're either doing it wrong or we want to see the gas burner you're using.

Frosty The Lucky.

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made the JABOD: fantastic! i can actually heat stuff up with this, even with wood which is kinda nice :P  Still have much to learn but dirt offers lots of chance for that.  now to learn about firepot depth and shape and steel position and tuyere opening and all that good stuff.  

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1 minute ago, (M) said:

made the JABOD: fantastic!

Give us photos!

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The trench is eased to clean and seems to give a better fire over all. I modified the forge (cold chisel) before forging a pick into a bick

It also holds just a little bit less fuel, the sides make holding the fuel in place easer and it reflects the heat. 

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 have one that I melted

 

 

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Single wall is similar to Viking style, no? Only I was at a demo a while back where Darrell Markewitz was showing off a setup involving a box of sand, two single lung bellows,  and a bellows stone (more durable than a clay wall I guess?)

He was basically piling up charcoal against the stone, with a shallow depression in the sand to lower the fire somewhat. I was impressed by how small the fire was whilst his bellows thrall needed to be watched in order to not burn the work. 

Link for reference: http://warehamforgeblog.blogspot.ca/2013/10/viking-age-sand-table-forge.html?m=1

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Just saw a superb demonstration of the beauty of the JABOD by Torbjörn Åhman on YouTube.  His channel is a pleasure to watch in general but this video is perfect for newcomers to see exactly what the JABOD is all about.  He doesn’t, however, use a trench....

https://youtu.be/m-R6iY-mY-Y

His videos are very family friendly and he practices safety and good smithing in all regards.  He doesn’t speak so cursing isn’t even an option.

Lou

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When I saw it I knew you had to see it!

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Simple effective equipment, SWEET.

Thanks for the link Lou, it's going on the club FB page in a minute.

Frosty The Lucky.

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I was very happy when TA posted that video. His content is great but i think he scares off beginners because there isn't commentary or step by step instructions like some other channels. My favorite video of his since the bloomery knife videos!

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Exo, some how I missed your coment, Soap stone melts at more than 2900f wile iron melts at 2800. In comparison, granite melts at 2300f and marble decomposes at half that. So yes, the use of a soap stone bellows guard works very well. Clay and clayed soils melts in excess of 3200f. So unless you can lay hands on soapstone, good old cob, adobe or brick is the answer. The down side of clay is the affinity it has for silica slag. 

Mr. Markewits forge works well, but as all sand filled forges suffers from the issue of slag, buy keeping the bowl shallow and the charcoal pile exposed he gets around this. One also assumes that he has less sand to carry and as demons are theater it has a certain cool factor. Mr. Mrkewits is dang good at what he dose and very knowledgeable. The easiest way to se his work is to rent Outlander. Not a great piece of cinema but it showcases his ironwork. 

If I had a reliable thrall I would certainly build one like his, tho clay cat litter would probably be my fill. 

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Hi,

my box is 16x16" and 8" deep. The box itself is on some fire bricks so that I don't worry about burning the wood underneath. About how deep and wide should I make the fire hole? I don't want to limit myself too much on what I can forge on it so not too small.

Does 4" wide 8" deep sound reasonable?

Right now I'm using charcoal since that's what I can get anywhere, but I'd like to use coal or coke eventually.

 

Thanks

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So with charcoal and a 3/4-1” tuyere I find a4x8” 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). Now 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

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