JABOD Question

[Dielonx5]

I pretty much just fell in love with the JABOD design. Super low barrier to entry with this set up and works just fine hey?

So my question is materials for fill. I live coastal and was wondering if beach sand mixture of some sort, to give it shaping ability, would suffice as fill for this type of forge design.

My choice of fuel would probably be bituminous coal, pretty sure there is a place within a few hours drive to get 50# @ 35 which is cheap for my area. Not sure if charcoal would be cheaper? Not really in a location to make it myself.

We do have tons of clay in the area, San Diego, but it is hard to find a place where it is legal to dig...

[JHCC]

Sand by itself clinkers badly and doesn’t hold its shape. Adding some clay (unscented cat litter will do) will help both.  

[Dielonx5]

Haha i read that more than a few times and seems so weird to use cat litter, but it is what it is. and what it is, is clay - and cheap!

[Charles R. Stevens]

Cat litter/drysweep give you two options, one you can mix it about 1/3 with sand, wet it and let it case in a bucket or sweater box and use it as adobe to form your hearth and fire bowl or you can just use it dry, and as with sand or the traditinal fly ash and clinker fill of British sideblasts just remake your fire bowl when you rebuild your fire. As you are using coal this is viable with out some kind of “bellows stone” to bank fuel against

 

[BIGGUNDOCTOR]

Clay from a pottery studio is also inexpensive. High fire clay bodies are pretty high temp at cone 10 -14+ (2,300f -2,500F range)

Hmmm, you live near a beach, yet you don't know where you could make charcoal..........      In the Bay Area you could build a fire on the beach as long as it was not higher than the high tide level. Personally I have used straight wood chunks when my coal got low and they worked fine for me. Thomas builds a fire next to the forge, then transfers the coals as the wood burns down.  If you have a place for a forge you have room for a charcoal retort.

And yes, charcoal is less expensive because you can get free wood to make it from.

 

[Dielonx5]

lol yeah we cant really just have a a fire on the beach here and most of the pits are taken up that are at beaches that have them, which is few. Don;t know that the neighbors would appreciate my making charcoal in this suburban neighborhood either, unfortunately :/

never thought of buying clay bodies from a studio or seller! That is a good idea! thank you (:

[Charles R. Stevens]

A proper regenerative charcoal kiln doesn’t make clouds of smoke, as it diverts the colitiles to the fire box to be burnt. 

[Dielonx5]

That makes sense, would burn similarly to a coal fire? Would the process of making charcoal put off a decent amount of smoke?

I've seen charcoal being made primitively using a method of creating a mud mound, and I have seen the method of basically "boiling" the wood lol - by that I mean the wood is cooked in a closed container with constant fire underneath. The latter method seemed to product a lot of smoke haha

[Charles R. Stevens]

http://www.instructables.com/id/How-to-Make-some-Charcoal/

with a indirect charcoal retort with the exhaust directed into the heating fire not near as much. On the scale of a standard wood fire. You use about a 1/3 of your wood as fuel to make the charcoal. 

As to charcoal as a fuel, one we are talking lump charcoal not brickets. Brickets are clay, coal and sawdust for the most part. Charcoal is lighter than coal, but contained the same BTU’s of energy. It will take twice the volume of charcoal to produce the same heat. This said, charcoal is particular, it likes a gental blast, and is much more effecent burned in a sideblast forge with a 3/4-1” ID tuyere (schedual 40 3/4” pipe is PDC to 7/8” ID) this will give you a fire that will heat about 6” of 1” stock. Measuring from the top of the tuyere to the top of the hearth we need 3” or so. I like a trench 8-10” long and 4” wide. You will want a bank or “bellows stone” some 4” high to bank charcoal against (due to fire spread you can’t bank the fire with additional fuel) some (Asian and African forges) prefer two banks forming a trench. 

This keeps your fuel use low and as we can only effectively hand forge 6” or so per heat is effective (swords, axes and spears have been forged this way for longer than we have used coal). If a longer fire is needed for heattreating a very long blade or for forging very large scrolls, space tuyeres out some 4-6” or so along a longer trench. 

Now with coal we can go bigger (but unless you are forging 2-6” stock under a power hammmer, why?) the difference in design is to ad a 1” space under the tuyere for slag to collect below the blast, mix clay (1/3) sand (2/3) and dope it with a bit of ash (optional) or use lose dry cat liter (traditinal fly ash and clinker). This is because slag sticks to vitrified clay (bricks and poetry) like glue!. You also need a bit more deapth (an inch of coal on the table will due) of fire. With coal we can eliminate the banks and go to a round bowl if one prefers. Buy adding the slag sump and using materials the slag won’t stick to your charcoal forge will happily burn coal. 

Now getting a bottom blast to burn charcoal is another mater. One must pile the charcoal deeper or convert to a duck nest (uses a steel puck with groves on the bottom to push air out the sides (like a gas burner on your stove). The larger/dealer fires are fuel hungry! 

On a note of charcoal, soft woods (soft in character, not in classification) not generaly used for cooking and heating fuel work well as they contain less silica and thus less ash is produced. Construction scrap, popular, willow (used in black powder) etc. being examples

 

[Dielonx5]

Charles,

Thank you so much for your detailed reply! I appreciate it so much!

Yes I figured as much as charcoal, not briquettes. Knowing that those were full of filler and how we want as little "Stuff" clogging up our airway which fuels the fire!

I haven't looked everywhere yet, but I was surprised that my local Home Depot only seemed to have galv piping. Any suggestions on where to look for non-galv pipe? My next idea was just to check the steel shop that would sell stock I need to buy anyway.

Definitely not planning on hitting metal much bigger than 1", if even that haha - especially getting into spring/tool steels. Only hand hammering over here! So, a massive fire is not needed as you have mentioned.

I am actually super glad you mentioned the note about coal and clay. I was planning on building the firepot from clay and filling the rest of the box with a make-shift adobe fill (cat litter and sand or something) because I want to have a structure that will surely not burn through the box haha. On that note, what would be a solid amount of layer beneath the fire pot to insulate the frame? I was thinking about 1.5" of fill which would meet the bottom of the fire pot - and continue to shape from there. Could cat litter be used as a substitute for the 1/3 clay to 2/3 sand?

On the topic of clinker, do you see any danger of coals/burning things to accidentally get into the tuyere when taking out clinker? (this would be in the event that there was enough build up in one day that clinker would need to be removed while the fire pot is hot?

[ShortMagPirate]

I found my pipe parts at Do It Best, they carry both galvanized and black, at least they do here. Otherwise any mom and pop type hardware store should have what you need.

 

[Mod34]

8 hours ago, Dielonx5 said:

Could cat litter be used as a substitute for the 1/3 clay to 2/3 sand?

No, the cat litter IS clay. 1/3 cat litter to 2/3 sand is what you want.

[Charles R. Stevens]

As natural gas and pro pain react with galvanized pipe (the coating flakes off and can clog the gas jets) ace, true value, home depo etc should have it. If your home depo sells gas hot water heaters they certainly should. If not a shallow glas or plastic pan filled with vinegar and lest a week will solve the problem. 

I use 2” (the thickness of a standard clay brick) as my minimum thickness between wood and the fire, so an adobe floor 2” thick. With a tuyere 8” or longer I wouldn’t wiry to much about coals in the tuyere, tho some sources recommend a down word angle to the tuyere. The first puff of air and the ash and coals will be pushed out.

As mod 34 points out cheep cat litter and drysweep are bentonite clay (a highly expansive clay when whet) 

 

 

[ThomasPowers]

What did Home Depot say when you asked them for the non-galvanized gas pipe?  I've never seen one that didn't stock it.

[Daswulf]

10 hours ago, Dielonx5 said:

I haven't looked everywhere yet, but I was surprised that my local Home Depot only seemed to have galv piping. Any suggestions on where to look for non-galv pipe? My next idea was just to check the steel shop that would sell stock I need to buy anyway.

Did you look "In" Home Depot or online? I have found the box store websites hard to navigate a bit and often without precise keywords things don't show up. My Home Depot carries all kinds of black pipe including the 2" stuff I used for my bottom blast forge. My lowes didn't carry the 2" stuff but had all manner of smaller black pipe. 

[arkie]

You can find black pipe at any plumbing supply shop. They can cut it to length and thread it for you as well.

[Frosty]

Just take a bucket or two to any site they're cleared to build another housing tract on and scoop up what you need. Nobody'll say anything so long as you aren't digging holes. Of course you could walk the beach till you come to a spot a bluff has collapsed and pick up as much as you want. With all the rain and mud slides finding suitable clayey mud can't be hard. 

Don't over think this thing, the JABOD is about as nothing special a forge as it gets once you step up from a hole in the dirt. All the "clay" does is hold it's shape, it's not like you're firing it into Grandma's China. Don't add so much water it turns into mud or it will shrink check as it dries like a mud puddle. Just enough water so you can squeeze it into a hard lump then ram it in with a mallet, rock, your fists if you're having one of THOSE days, whatever. Just plain old dirt works fine. 

Give it 1.5: - 2" of dirt between the fire and wood and you'll be golden. If you want to be sure you can mix up a saturated solution of 20 Muleteam laundry borax and water and give the wood a good soaking. When dry it'll be fire resistant.

A indirect charcoal retort doesn't smoke, the smoke is the fuel to pyrolize the wood. A steel bucket or small barrel with a snap on lid is the retort. Plumb an elbow or two and a couple short nipples from the bung so the smoke ends up directed back under the edge of the bucket, barrel, etc. Laid with the smoke outlet under the retort in the draft opening (air intake) the smoke will be drawn into the fire and reburned. You begin the process with a small scrap wood fire under the retort. Shortly after the wood starts cooking in the retort just the smoke is enough fuel to continue the process stop feeding the scrap fire. You'll know when it's cooked because the smoke will slow down to where it won't support a fire, at which time you cover the draft opening with dirt and let it cool.

If you're concerned about the neighbors you can use BBQ briquettes to start the process and toast a hot dog if the FD comes around snooping. It's actually a really smoke free process and in any case less likely to get complaints than the smell of coal smoke.

Frosty The Lucky.

[Dielonx5]

Awesome! Thank you all for your replies. HD did have black piping I was just unsure about the coating on the outside of the pipe and it with with fire. Will pick some of that up!

2 inches thick sounds pretty solid! Just wasnt to be super safe is all (:

Word. Keep it simple! After all, it's just a box of dirt.

 

I think I will start with coal for now and look into making charcoal but you're right. The doom looking yellow smoke.and it's smell might cause more fright than the smell of a campfire haha

[Daswulf]

No, 2" diameter, not thickness. That's what works well for a bottom blast forge. You are building a jabod so use what Charles suggested." (schedual 40 3/4” pipe is PDC to 7/8” ID)"

i was just pointing out that they had black pipe in variety. 

[Frosty]

The factory coating on black pipe isn't particularly toxic it's okay to let it burn off. Stay out of the smoke to be safe though, no reason to breath oil or plastic or whatever it is smoke if you don't have to.

Frosty The Lucky.

[Dielonx5]

oh yeah was planning on buying a 3/4" pipe, I was noting that a 2" thick bottom layer on the JABOD sounds good as far as insulation so the wood box doesn't burn and my fire drops out of the bottom haha!

But yeah, a 2" tuyere would be awesome! Would definitely get a FD call to the house though because that fire would be raging hahaha.

 

Word thanks frosty! Appreciate the note about it not being too bad to burn off. That was my concern haha..burning the plastic coating of the black pipe. But I suppose only a small amount will burn off anyway.

Well I have the box built. Just need to raid a construction site or collect beach sand and buy some cat litter

[Charles R. Stevens]

With your cast iron pan you could have forgone the 2” bottom layer to bring the fire down closer to anvil hight.

[Dielonx5]

I'm guessing that the bottom layer of wood creating the box becoming warm/hot to the touch is normal? 

I just made a small fireto test out the completed forge and noticed the bottom board beneath the fore was barely noticeably warm, but I only had it to orange heat for maybe 20 minutes. 

I may add a 1/2" to the bottom of the pot because I am a little paranoid but the bottom should be 2" off the deck.

 

Also, my fire pot edge extends about two inches at a diagonal over the tuyere,  this should be okay right? I'm assuming the adobe mixture will insulate the pipe enough

[Charles R. Stevens]

Flashpoint on wood is 450-500F if I remember right. If your using charcoal you can aliminate the 1 inch gap  between the floor and the bottom of tuyere. But if you can hold your hand on it for more than 5-10sec. I wouldn’t worry about it.  

I make the wall vertical but the tuyere is generally flush with the clay.

[Dielonx5]

I have some coal coming soon and will give the forge a proper firing once it arrives and we will see what happens haha. Fire extinguisher at the ready...just kidding I'm sure it will be okay I'm just a little paranoid. The highest heat point won't be at the bottom and once there is more ash and coal there will be better insulation.

Was thinking of doing straight walls but the firepots I've worked with have been angled and I wanted the tuyere to blow air into the bottom center, it is still flush with clay but the layers above taper to an opening of about 2 inches wider than the depth of the tuyere