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INTERNS, WORKTRADERS & SUPPORTERS !  

Below are blog entries by Laura Lutrell 

The Strawbale Studio is the place in Michigan where the 2-week workshop took place that I wrote about building the small cottage. I returned there to work and learn from Deanne Bednar, the coordinator and with her other fall interns from mid August through mid September.

Ernie watching the pocket rocket burn off  the paint on the can. The paper mâche catches  some of the heavy metals from the paint

When I arrived, Deanne was preparing for two workshops with Ernie and Erica Wisner.  They came and did a Pocket Rocket workshop in Detroit and a Rocket Mass Heater workshop at the Strawbale Studio.  The Pocket Rocket is more of an emergency heater.  You can build it out of a large can and a couple of stove pipes.  Burning wood in it puts off a tremendous amount of heat and (after the initial burn) will burn a very efficient fire with no visible smoke. 

Ernie with the inside of a rocket mass heater

The Rocket Mass Heater also burns a very clean fire, but it operates differently.  The wood fire is built in an area to the side and the draft of the system pulls the fire into the burn chamber (across the bottom) and up the heat riser (a chimney of soft insulated refractory bricks) in the middle of an external 50-gallon barrel.  The heat from the riser starts radiating out of the barrel at the top and the gasses begin to cool as heat radiates out of the barrel and the gasses drop down the sides.  At the bottom of the barrel, the hot gasses move into a system of stove pipe that is buried in an earthen bench, bed, floor, etc. before exiting out the ceiling, like a regular chimney. The idea is that, in addition to the radiant heat off the barrel, the heat from the fire exhaust heats the mass built around the stove pipe and then that mass holds the heat and slowly radiates it.  Even after the fire has been out for hours, you can sit on the bench and still be warm. It is better to heat a mass than heat air if you want to store the heat and access it over a longer period of time. Genius. Ernie and Erica have provided excellent information and drawings on them here... 

Deanne's Rocket Mass Heater  (the box on the barrel is an example of cooking on top of the barrel)

Ernie and Erica stayed about a week longer and it was interesting and enjoyable to spend that time learning and hanging out with them.

The earthen plastered door, drying

interior plastered wall

After that, I went to work plastering.  I decided I wanted more experience in this FANTASTIC and beautiful medium.  First, I plastered over the plywood walls of one of Deanne's little cabins.  She had built a rumford fireplace in there and wanted the surrounding walls to look nicer, be less susceptible to catching fire, and create a bit of mass to absorb some of the heat from the fire... earthen plaster does all of those things! I plastered the door, the wall, ceiling, and 2x4s that framed in that section. The plaster was made out of 1/8" sifted earth from the land (which had a combination of clay and sand), a little extra sand, dried and sifted horse manure (for fiber to hold it together), water, and a little wheat paste (white flour and water cooked into a paste). That little section gave me a lot of practice in going around corners, how much pressure to apply, what it takes to make sure the plaster is sticking, and more.  It was fun and I think it looked really good.


Two other interns arrived and we all set to work plastering another coat on the retreat cabin (the little cottage from the workshop).  The strawbales we used were really loose and uneven (apparently due to the drought this year), so this cabin took a lot more coats of plaster to even out the surface than your standard strawbale building...

 




Later I made 3 panels (on plywood) with earthen plasters and a little kaolin clay (the white part) to experiment with sculpture/relief images... Amazing how artistic you can be.  Your imagination is the only limit.  I didn't finish working on them before I left, but here's the beginnings.               

When the interns arrived, we all went to the Renaissance Festival together. A woman I had met from a Strawbale Studio tour painted my face and we saw some shows. We met some interesting characters too. This man had massive pickle sales...







After the rocket mass heater workshop, we learned so much, that we went back to the one that Deanne built a few years ago and made some modifications. Mainly, the distance between the barrel and the top of the heat riser should be between 2" and 2.5". Since we were adjusting this, we also built a little cob bevel on top of the heat riser so the ashes would fall to the bottom instead of getting caught on top and interrupting the flow of gasses. Then we replaced the earthen sill and seal around the rim of the barrel and voila - improved rocket mass heater!

Cob Tiles in Frames Earthen Plaster, and Kaolin Plaster (with different fibers)

Oliver (an intern) and I decided to make floor samples, so we could see a wide variety of applications and what the differences would be.  This turned into a pretty big project.  We made 12 small tiles (after making little wooden frames for them) out of cob (clay, sand, fiber and water) and then applied various finish plasters to them including earthen plaster or kaolin plaster (with white clay and sand), then a thin layer that included an earthen pigment (an "alis").

Look at all the varieties we tried (a small sampling, really)

We included some mica (shiny mineral for strength and prettiness).

We even did a little wet fresco! (Now I understand how all those Italians I studied made their paintings!)

gravel, lava rock, slip straw, cob

I'm hoping Oliver did the linseed and/or hemp oil coatings (hardening coat) and will let me know how those turned out (that is the last stage of these samples).

Oliver also made a subfloor demonstration model so people can see different ways to build a subfloor below the earthen plaster finish layers.





The biggest project we undertook was working on the Kid's Cottage that Deanne built several years ago.  During the Rocket workshop, Ernie and Erica had the participants make a few changes that would help it run efficiently. Then the other interns and I secured the stove pipes in place, made a small cob wall to separate the floor space from the insulation under the benches, and installed the insulation (a perlite/vermiculite clay slip mixture) and began adding cob that would form the benches. This was a long process with a lot of learning along the way. In the end, we decided we should have just added the perlite and vermiculite without any slip and that is what we did towards the end.

Perlite/Vermiculite Slip Insulation

Small cob wall to separate insulation from floor area

Cob over the insulation to start the bench area

mixing the insulation for the Kid's Cottage

 
Some other interesting and fun endeavors... 

Milking a goat!

  * I learned to milk goats with one of the neighbors.

Making a Living Roof

  * We built half of a living roof on the wood shed (plants growing in soil on
  a pond liner as the roof!)
  * Found the dimensions to install a metal roof on a future sauna building
  * Replaced some of the thatch roof on the spiral chamber (a tiny building that
  holds the composting toilet)
  * Learned a lot about plants and herbs. There is a huge variety on
  the property there.  I want to learn more about plants!
  * Learned some permaculture principles from a local expert in order to prep   
   the greenhouse for winter growing.

Oliver measuring sauna roof

The greenhouse before

The greenhouse after

* Made a framework for a "Ready-Up" Tent out of poles harvested from the property

* Had a knots and lashing learning evening including: Miller's knot, Trucker's hitch, Tripod lashing, Handle lashing, and Love knots! 

See lashing examples 

Handle lashing is Great!

* Began sculpting a new turtle earth oven at the Kensington Metro Park. 

sculpting the Earth Oven turtle with fall interns

The beginning of a turtle sculpted on an earth oven

"Rock and Roll" Cob Mixing

 As you can see, a lot went on during that time!