Adobe brick forge

[Jay.bro]

So I know this has probably been discussed on here before and I've tried to find something on it but I've had no luck. Would building a forge, such as a side draft forge, entirely from adobe brick actually work? All I plan on burning is charcoal but I don't know if adobe can withstand that amount of heat if I find a dirt that's mostly clay. Thanks in advance for your knowledge on this subject.

[Daswulf]

I have seen many posts on here saying Adobe will work. 

https://www.iforgeiron.com/topic/44842-just-a-box-of-dirt-or-a-simple-side-blast-forge/?page=3#comment-508854

[Glenn]

What fuel are you going to use?

Please read the JABOD posts at https://www.iforgeiron.com/forum/64-solid-fuel-forges/.

 

I will move this to the forges section.

[ThomasPowers]

Well they have been doing it that way for about 2000 years; so you have a sporting chance of it working.  The big thing is to make sure the design is tweaked for the material used--ie don't try to mimic a brick forge with adobe as it's weaker than bricks, so no arches, more a monolithic block made of adobe bricks.

[Jay.bro]

Okay I'm gonna be using charcoal and all I found was it gets messed up from the heat and I wanted to do all of it even the fire pot with Adobe but all I found was stuff talking about using it as a decorative thing around the actual fire pot and forge but nothing I had seen said anything about building it entirely from it. I think the search feature on this site is lacking sometimes it works sometimes it doesnt. I was just thinking a small circular forge for small knives and decorative iron work. I have looked at the jabod thread a few times and some videos on it I've considered it I just was wondering about trying this aproach as mud brick is less flammable than wood.

[ThomasPowers]

Clinker can stick to adobe and need to be pried off; but that is not difficult and repair is simple.  Adobe may crack as it dries, not a problem just fill the cracks with more adobe.

What other issues did you see mentioned?

[Glenn]

Use google or other search engines. Type in *search, the search words, and iforgeiron.com*  

[Jay.bro]

Mainly people saying something about it vitrifying and falling apart and something about it can collapse in the tuyere but I figured if I built it right I could avoid those problems.

[ThomasPowers]

Vitrifying and falling apart?  Sounds like normal wear---how do you keep your car tires from wearing out?  Don't drive on them!  

*EVERYTHING* in a blacksmith shop is a consumable---including the smith!

I've been using soil, creek clay, adobe forges since 1981  and I don't understand the "collapse in the tuyere comment"  guess someone is using a different way than all the ways I have tried....

[Frosty]

Adobe will work just fine. To avoid it checking as it dries don't make mud and trowel it in. Only add just enough water it will squeeze into a lump in your fist then ram it in shape with a wood mallet, b ball bat on end, etc. The mix makes a difference too, this isn't a structural use it needs to be able to expand and contract without breaking up and needs to "breathe." 2 pts sand to 1pt clay does the trick. The sand allows the particles to shift position with thermal cycling so cracks don't form easily and it provides enough porosity any moisture can escape without building pressure.

A side blast puts the tuyere pipe where the clay can collapse if it needs to without plugging the air. Like Thomas says repair is as easy as ramming in fresh clay. I have a cast iron rivet forge, clay it and repair it regularly in use. I just spank more clay sand mix in place with the forge scoop shovel. 

A few inches of clay will keep a wooden box from getting hot let alone burning.

Frosty The Lucky.

[Charles R. Stevens]

The box of dirt is acualy a clay forge. If one got it hot enugh it would be a dang brick. Adobe is 10-30% clay 30-70# sand. Straw ( dry yellow grass or even chopped sisal rope) helps with cracking as it dries. If layed up as mud pies insted of brick it is then cob. A round , square or rectangle 30" across and anvil high solid mass except for about the top 6" wich has a bowl or trench works. As TP points out they have (and still do) use Adobe and cob forges world wide. An Adobe would be very appropriate to the southwestern Us, a cob to the northwest or England or France. It has been shown that Adobe structures can infact be fired (been done buy the guy who started cal earth) and soft fired Adobe bricks have also been around a long time. Rain will not be your friend, tho. An Adobe forge with a constatina bellows and a Spanish style anvil would be sweet in west Texas, new medico, Arizona, Colorado...

anyway, I would suggest building the box of dirt so you can experiment with your fire bowl depth, shape and size, then then build a more substantial and permanent forge. 

Now as to the tuyere, a traditional side blast Adobe would use either a trench covered by a flat stone ( keeps the soil from caving in) or a series of fired clay cones (small clay plant pots with the drain hole enlarged, their is come evidence the Vikings used heavy copper tuyere in their blumudary furnaces, but for our needs a piece of 2/3" schedual 40 black pipe will do just fine. Now I used a bed inflator pump on both the mark I and mark II dirt boxes, the mark I used a Intex double Quick III hand pump and the markIi used an Intex electric. The hand pump is half as expensive, quitter, and more fuel effecent. The electric requires a valve, and I prefer a "T" to vent air.. I have sense desided I prefer a 4x8-12" trench to the round bowl, one then can either mold 4" high sides or use bricks to help contain the fuel. Clinker dosnt stick all that much to 10 clay above, but it sticks like glue to the rich clay soil I use. 

This should get you a start, any other questions, ask. We will either help you find the answers, help you figure it out or we will explained it to you, typically in that order.