Cob Oven Prep

On July 1st  to the weekend we are trying to construct a cob oven. Any help is welcome.

Does anyone have any of the following laying around?

1) patio stones (or such)
2) lumber  
3) 45 gallon drum
4) bale of straw
5) firebrick  
6) 4x4 post-holders
7) old fence posts (the solid T-shaped kind),
8 ) old metal bedframe
9) old tiles (even broken) to use for 'mosaic' countertop
10) piece of stovepipe
10 'slaking buckets' (from 5 gallon utility pails up to rubbermaid garbage cans).
11) picks and pry-bars
12) tamper

I've found 8 & 3

I found 5) (at a store)

Cheat to win!

Reb tracked down rumours of two patio stones...

We'll do some more cheating on the weekend if needed.

This is an oven with a short chimney and shallow throat.
It is what we will have to resort to if our funding partners and stakeholders do not monetize our ultimate vision.
Sure it'll cook better, but Moloch will be displeased!

If wood pallets counts as lumber, then I've got it covered! I'm going to make a phone call about patio slabs. A customer of mine just re-did the landscaping around her house, and I either saw a bunch of patio slabs which were pulled up for the new, or saw new that she'll be putting in...will let you know, as I have her dad's number and will ask him if he knows of any spare patio slabs.

Any help is appreciated, Marc!

I should be picking up at least 4 patio slabs early next week - either 2' x 2' or 2' x 2-1/2'. Will update after I've gotten them.

We can strike off 6) and 7), the bedframe will suffice.

We should add 'buckets' to the list (from 5 gallon utility pails up to rubbermaid garbage cans). These are for use in 'slaking' the clay and turn it into a 'slip'. (ooh the terminology). I already managed to scavenge one pail from the forest near home, but we can use more.

Other than that and the straw bale(s) (let's aim to get 2) it looks like we're basically good to go. I'll grab them from Jetty's (https://www.jettys.ca/product-page/hay-bale) if none materialize by next week.

New side profile plan image:    
From the bottom to the top:
    1) Remove topsoil  
    - remove spongey roots, wood, tarps, etc
     - only strip areas for stones, they will be laid right onto clay substrate.
       3) Construct 4x4 barrel anchoring 'cross'
      - Cross lays flat on the ground, width=barrel diameter
       - Anchored to ground with fence spikes
        - Bolted to bottom of barrel with lag bolts
    4) Chop up barrel  - cut to height such that oven deck is at working level (elbow height)  - grind off 'legs' from top perimeter
    5) Secure barrel  
    - If it's really oily, stuff it with straw  
    - Turn it upside down and bolt it to the cross
    6) Construct pentagon deck extension  
    - 4x4 hexagon, just fits around barrel at upper rim  - extends the upper surface of the barrel by 8"  
    - built with nails, secured to barrel with lag bolts through barrel
    7) Construct oven deck  
    - lay a 3" layer of 'normal cob' (with straw) on top of extended barrel top  
    - form a 'cob dam' rim, fill and level with loose sand  
    - lay firebrick in 'herring bone' pattern, with extended section for doorway
    - secure firebrick with metal strapping hoop
    Construct sandform
     - main part is a 26 inch diameter hemisphere made of damp sand (with tiny bit of clay), possibly with some filler at the center (firewood or hay or whatever digs out easy)
      - oven doorway, chimney,  and arch are constructed at the same time, images to come ....
      - cover sand form with wet newspaper to form a 'mold break/release'
    9) Cob the inner layer of the oven
     - composed of 'thermal' or 'refractory' cob, a mixture  high in sand and containing no straw
     - includes the dome and the archway/chimney
     10) Cob the outer layer of the oven
       - composed of 'normal cob' enough clay to be 'rubbery' and enough straw to be insulative and cohesive
       - again go over the dome and the archway/chimney
   11) Build the roof
       - dismount sattelite dish
       - install brackets to receive poplar roof supports
       - shingle dish with cedar shims, secured with #8 panhead screws through pre-drilled holes in shingles, directly into mesh
       - mark out footing locations for roof poles, set bedding stones down to substrate, drive fencepost spikes
       - erect roof posts and hold in place with temporary cross-braces (external, connect to ground)
       - raise the roof into position and secure to brackets
       - install permanent cross bracing (internal, pentagram)
      - secure roof cap
11.2) Lay patio stones
- Ring of stones to support oven
- Square of stones in front for standing

   12) Dig the oven
       - take time, don't go fast
       - allow to 'crisp up' a bit, then do some smoothing around arch
       - light the first fire and keep it burning until structure is dry (hours and hours and hours)
   13) Plaster/decorate the oven
        - after trimming dried straw, a 'plaster' cob (lots of clay, no straw) can be smeared over to smooth the external layer
         - This is when you can get crazy artistic
   14)  Make counter space
        - connections between roof supports and oven deck hexagon form basis for countertop on either side of door
         - can be planked in with pallette wood etc, then cobbed over and tiled
  15) Celebrate!  Eat! Be merry!

Archway detail: