Two new builds, one experimental

Earlier this year I've attended a rocket building weekend, with an enthusiastic group led by Peter Berg himself we build two stoves, one super quick heater and a experimental stove with bench, oven and dual pit furnace!

The first one to give some quick heat to the room(an old stable):

Three barrels stacked with a casted fire chamber:






The finished stove with loam coating:


The stove has a p-channel in the fire chamber that adds a lot of extra air to the process. The thing starts blazing in a few minutes and the top barrel sends out nice heat radiation, after a few minutes the room is rising noticeable in temperature.


The other one is more of an experiment:

The fire chamber is made of fireproof brick and the rest from streetbricks(dunno the proper English word for it):




The door is from an old woodstove:


It performs quite good when hot but it still needs something to help it heat up, because the complicated channel blowback is a problem until it's hot.

A sketchup view:


And the plans for the second one:
http://www.pberg.demon.nl/pictures/Batchbox/workshopZeddam/fornuis.skp

Both the second stove and the casted fire chamber were designed by Peter Berg, he also supervised the building process.

Johan, I like how you covered the barrels, what material did you use and how did you get it to stick to the metal? thanks alan

- Does any one else remember seeing this as an under 10 minute video here or at Donkey **? Big AL !

Alan Mikoleit wrote:Johan, I like how you covered the barrels, what material did you use and how did you get it to stick to the metal? thanks alan

We had a wire mesh that was covered in some sort of terra cotta that we tied around the build before we put on the loam.(loam is the right English word for the clay-like stuff right?)

allen lumley wrote: - Does any one else remember seeing this as an under 10 minute video here or at Donkey **? Big AL !

I haven't seen it here before but I know that the build was documented and put on Youtube:
http://www.youtube.com/watch?feature=player_embedded&v=pfyOSengWTk

http://www.youtube.com/watch?feature=player_embedded&v=JQe1hSwQ6Ac

Johan T. : thank you, that must be where I saw it ! Big Al !

Alan Mikoleit wrote:Johan, I like how you covered the barrels, what material did you use and how did you get it to stick to the metal?

The barrels were covered with cardboard first and after that with the wire mesh. This type of mesh is called lath, I am led to believe. The cardboard was done as an experiment and it turned out to be a very smoky business because we couldn't keep the cob layer airtight... In retrospect, we should have used ceramic paper instead to compensate for the expansion of the barrels.

The stove did what was hoped for, by the way. The top barrel radiated lots of heat from the first minute and the covered part got hot enough to burn one's hands despite the 2" layer of cob. This layer could be as thick as 4" I would say, even 6" maybe. But that hasn't been realised yet.

Hi what did you use to stick the street bricks together?

Paul

Paul Carter : damn the Auto correct do you mean Heat Bricks A.K.A. fire bricks !?!! big AL?

paul carter wrote:Hi what did you use to stick the street bricks together?

You'd see that correctly, the outside of the cooking range is made of concrete street bricks. Lots of mass and at the location there happened to be about 600 of those, just for grabs. We built that range using plaster quality loam, a standard concoction of clay, sand and small hemp fibres. A little more difficult laying bricks with that, but it worked.

Peter Berg wrote:

Alan Mikoleit wrote:Johan, I like how you covered the barrels, what material did you use and how did you get it to stick to the metal?

The barrels were covered with cardboard first and after that with the wire mesh. This type of mesh is called lath, I am led to believe. The cardboard was done as an experiment and it turned out to be a very smoky business because we couldn't keep the cob layer airtight... In retrospect, we should have used ceramic paper instead to compensate for the expansion of the barrels.

The stove did what was hoped for, by the way. The top barrel radiated lots of heat from the first minute and the covered part got hot enough to burn one's hands despite the 2" layer of cob. This layer could be as thick as 4" I would say, even 6" maybe. But that hasn't been realised yet.

Hi Peter, excuse me for butting in as this is just my second post on permies.com. I´m facinated by this design as it incorporates mass without all the ducting and bench making, which is great but isn´t suitable to all situations. Would you mind clarifying some of the materials used in the construction. Johan mentions that the mesh is firstly coated with ¨some sort of terra cotta¨ What´s the purpose of this layer and what exactly is it. He also says that the outer layer is Loam, Wikipedia ¨ Loam is soil composed of sand, silt, and clay in relatively even concentration (about 40-40-20% concentration respectively)¨ or is it actually cob? Thanks in advance. Stephen.

Peter thanks for bringing your expertise to these forums and for the 2 video links! Does adding adding a second or third bell to the system recover more heat as in the dragon core flue heater. If one tall bell on the riser is sufficient then that's all I will do. I have been told Home Depo sells a 1/8 and 1/4 inch thick heat shield blanket that we can use instead of your cardboard. The Boom Squish DVD says to never pat down or compress the cob, so I laughed as you did a very good job of that LOL. Alan

Stephen McCarthy wrote:Johan mentions that the mesh is firstly coated with ¨some sort of terra cotta¨ What´s the purpose of this layer and what exactly is it. He also says that the outer layer is Loam, Wikipedia ¨ Loam is soil composed of sand, silt, and clay in relatively even concentration (about 40-40-20% concentration respectively)¨ or is it actually cob?

Maybe, just maybe the wire mesh with the blobs of baked terracotta on every cross could be typically Dutch?

Wikipedia gives this explanation: "Lath may also refer to wire mesh, typically with a paper backing, that is applied to a wood or metal framework as matrix over which stucco is applied. One of the key elements of lath, whether wooden slats or wire mesh, are the openings or gaps that allow plaster or stucco to ooze behind and form a stronger bond to the lath itself."

Because of the terracotta blobs there's always room behind the mesh so this is all around inside the loam when plastering is finished. As such it acts as a reinforcement, the whole plasterwork is coming loose from the metal without falling down. In effect, the plasterwork do become a more or less free standing cob wall around the barrels. Quite nifty, don't you think?

And yes, loam is similar to cob, but in my opinion loam is the finer version of more or less the same substance.

Thanks for this post! Where do you source the P-Channel casted Fire Chamber?

Hi David,

Welcome to Permies.

The cast batch box firebox was developed 10+ years ago by Peter van den Berg. He does not build them for sale, but freely publishes the directions for making one. He has more recent versions of the design, too. You can find all the information you need at batchrocket.eu.