Cob Oven Workshop with Tom Trout - United...

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Cob Oven Workshop with Tom Trout

Transcript of Cob Oven Workshop with Tom Trout - United...

Page 1: Cob Oven Workshop with Tom Trout - United Diversitylibrary.uniteddiversity.coop/Ecological_Building/Cob_Ovens/Building_a_cob_oven-In...Dan Givens from Alaska prepares a base for the

Cob Oven Workshop with Tom Trout

Page 2: Cob Oven Workshop with Tom Trout - United Diversitylibrary.uniteddiversity.coop/Ecological_Building/Cob_Ovens/Building_a_cob_oven-In...Dan Givens from Alaska prepares a base for the

Dan Givens from Alaska prepares a base for the oven. The oven is temporary and will be

dismantled after the workshop.

Page 3: Cob Oven Workshop with Tom Trout - United Diversitylibrary.uniteddiversity.coop/Ecological_Building/Cob_Ovens/Building_a_cob_oven-In...Dan Givens from Alaska prepares a base for the

Tom Trout has brought a load of local clay from an excavation site mixed with straw.

Page 4: Cob Oven Workshop with Tom Trout - United Diversitylibrary.uniteddiversity.coop/Ecological_Building/Cob_Ovens/Building_a_cob_oven-In...Dan Givens from Alaska prepares a base for the

The hearth is recycled firebrick laid dry. Tom spots the door plug in place with cob.

Page 5: Cob Oven Workshop with Tom Trout - United Diversitylibrary.uniteddiversity.coop/Ecological_Building/Cob_Ovens/Building_a_cob_oven-In...Dan Givens from Alaska prepares a base for the

The oval shape of the oven is sketched out on the hearth. The oven shape is based on the

traditional

Quebec oven, and can be described as a "crouching groundhog". In Quebec it is described

as a

beaver.

Scaled drawings for a slightly larger shape can be found at the 2003 French Oven

Workshop

Page 6: Cob Oven Workshop with Tom Trout - United Diversitylibrary.uniteddiversity.coop/Ecological_Building/Cob_Ovens/Building_a_cob_oven-In...Dan Givens from Alaska prepares a base for the

Damp sand is used to form a mold for the clay oven shape.

Page 7: Cob Oven Workshop with Tom Trout - United Diversitylibrary.uniteddiversity.coop/Ecological_Building/Cob_Ovens/Building_a_cob_oven-In...Dan Givens from Alaska prepares a base for the

Sand is packed in place.

Page 8: Cob Oven Workshop with Tom Trout - United Diversitylibrary.uniteddiversity.coop/Ecological_Building/Cob_Ovens/Building_a_cob_oven-In...Dan Givens from Alaska prepares a base for the

Firebricks are used to shape the edge of the sand. John Rousseau wets the sand.

Page 9: Cob Oven Workshop with Tom Trout - United Diversitylibrary.uniteddiversity.coop/Ecological_Building/Cob_Ovens/Building_a_cob_oven-In...Dan Givens from Alaska prepares a base for the

John and Tom prepare cob. Water is added and the mix is worked into

bread loaf shaped lumps that are laid on the form

Page 10: Cob Oven Workshop with Tom Trout - United Diversitylibrary.uniteddiversity.coop/Ecological_Building/Cob_Ovens/Building_a_cob_oven-In...Dan Givens from Alaska prepares a base for the

Additional firebricks.

Page 11: Cob Oven Workshop with Tom Trout - United Diversitylibrary.uniteddiversity.coop/Ecological_Building/Cob_Ovens/Building_a_cob_oven-In...Dan Givens from Alaska prepares a base for the
Page 12: Cob Oven Workshop with Tom Trout - United Diversitylibrary.uniteddiversity.coop/Ecological_Building/Cob_Ovens/Building_a_cob_oven-In...Dan Givens from Alaska prepares a base for the

Preparing cob. Footpower is fun.

Page 13: Cob Oven Workshop with Tom Trout - United Diversitylibrary.uniteddiversity.coop/Ecological_Building/Cob_Ovens/Building_a_cob_oven-In...Dan Givens from Alaska prepares a base for the

Preparing cob lumps ready for placing on the sand form.

Page 14: Cob Oven Workshop with Tom Trout - United Diversitylibrary.uniteddiversity.coop/Ecological_Building/Cob_Ovens/Building_a_cob_oven-In...Dan Givens from Alaska prepares a base for the
Page 15: Cob Oven Workshop with Tom Trout - United Diversitylibrary.uniteddiversity.coop/Ecological_Building/Cob_Ovens/Building_a_cob_oven-In...Dan Givens from Alaska prepares a base for the
Page 16: Cob Oven Workshop with Tom Trout - United Diversitylibrary.uniteddiversity.coop/Ecological_Building/Cob_Ovens/Building_a_cob_oven-In...Dan Givens from Alaska prepares a base for the
Page 17: Cob Oven Workshop with Tom Trout - United Diversitylibrary.uniteddiversity.coop/Ecological_Building/Cob_Ovens/Building_a_cob_oven-In...Dan Givens from Alaska prepares a base for the
Page 18: Cob Oven Workshop with Tom Trout - United Diversitylibrary.uniteddiversity.coop/Ecological_Building/Cob_Ovens/Building_a_cob_oven-In...Dan Givens from Alaska prepares a base for the

The goal is to get approximately a 4 - 9" thickness. In a more permanent oven, the first

layer would

be adobe (clay and sand) instead of cob (clay and straw). This is described in thorough

detail in

Kiko Denzer excellent book Build Your Own Earth Oven.

Page 19: Cob Oven Workshop with Tom Trout - United Diversitylibrary.uniteddiversity.coop/Ecological_Building/Cob_Ovens/Building_a_cob_oven-In...Dan Givens from Alaska prepares a base for the

As the layers are placed, finger holes are added to provide a key for the next layer.

Page 20: Cob Oven Workshop with Tom Trout - United Diversitylibrary.uniteddiversity.coop/Ecological_Building/Cob_Ovens/Building_a_cob_oven-In...Dan Givens from Alaska prepares a base for the
Page 21: Cob Oven Workshop with Tom Trout - United Diversitylibrary.uniteddiversity.coop/Ecological_Building/Cob_Ovens/Building_a_cob_oven-In...Dan Givens from Alaska prepares a base for the

The oven is built on Tuesday - total time, about 2 hours. There will be a pizza party on

Thursday,

so we need an accelerated drying schedule.

Patrice Dupont lights a fire immediately, in order to burn out the door plug and start

drying the clay.

After the plug is gone, sand is gradually removed and the fire is pushed inside the oven

Page 22: Cob Oven Workshop with Tom Trout - United Diversitylibrary.uniteddiversity.coop/Ecological_Building/Cob_Ovens/Building_a_cob_oven-In...Dan Givens from Alaska prepares a base for the

Patrice Dupont and Pat Manley check for warmth as Scott Goodman looks on.

Page 23: Cob Oven Workshop with Tom Trout - United Diversitylibrary.uniteddiversity.coop/Ecological_Building/Cob_Ovens/Building_a_cob_oven-In...Dan Givens from Alaska prepares a base for the
Page 24: Cob Oven Workshop with Tom Trout - United Diversitylibrary.uniteddiversity.coop/Ecological_Building/Cob_Ovens/Building_a_cob_oven-In...Dan Givens from Alaska prepares a base for the

Decorative touches are added as the oven dries.

Page 25: Cob Oven Workshop with Tom Trout - United Diversitylibrary.uniteddiversity.coop/Ecological_Building/Cob_Ovens/Building_a_cob_oven-In...Dan Givens from Alaska prepares a base for the
Page 26: Cob Oven Workshop with Tom Trout - United Diversitylibrary.uniteddiversity.coop/Ecological_Building/Cob_Ovens/Building_a_cob_oven-In...Dan Givens from Alaska prepares a base for the

The fire progresses inside the oven.

Page 27: Cob Oven Workshop with Tom Trout - United Diversitylibrary.uniteddiversity.coop/Ecological_Building/Cob_Ovens/Building_a_cob_oven-In...Dan Givens from Alaska prepares a base for the

Sand is gone, and the front of the oven is dry.

Page 28: Cob Oven Workshop with Tom Trout - United Diversitylibrary.uniteddiversity.coop/Ecological_Building/Cob_Ovens/Building_a_cob_oven-In...Dan Givens from Alaska prepares a base for the

Note the dry patch at the front (left) top.

Page 29: Cob Oven Workshop with Tom Trout - United Diversitylibrary.uniteddiversity.coop/Ecological_Building/Cob_Ovens/Building_a_cob_oven-In...Dan Givens from Alaska prepares a base for the

Various air systems were tried to speed up the burn. Air is entering at the bottom, and

smoke

is exiting at the top.

Page 30: Cob Oven Workshop with Tom Trout - United Diversitylibrary.uniteddiversity.coop/Ecological_Building/Cob_Ovens/Building_a_cob_oven-In...Dan Givens from Alaska prepares a base for the

Fire is hot enough to ignite smoke that is leaving the oven.

Page 31: Cob Oven Workshop with Tom Trout - United Diversitylibrary.uniteddiversity.coop/Ecological_Building/Cob_Ovens/Building_a_cob_oven-In...Dan Givens from Alaska prepares a base for the

A torch test on the clay. This particular local clay does not fire very hard. The surface is

still quite

water absorbent, but abrades somewhat less.

Page 32: Cob Oven Workshop with Tom Trout - United Diversitylibrary.uniteddiversity.coop/Ecological_Building/Cob_Ovens/Building_a_cob_oven-In...Dan Givens from Alaska prepares a base for the
Page 33: Cob Oven Workshop with Tom Trout - United Diversitylibrary.uniteddiversity.coop/Ecological_Building/Cob_Ovens/Building_a_cob_oven-In...Dan Givens from Alaska prepares a base for the

Pizza time. William Davenport and Tom Trout display their skills.

Page 34: Cob Oven Workshop with Tom Trout - United Diversitylibrary.uniteddiversity.coop/Ecological_Building/Cob_Ovens/Building_a_cob_oven-In...Dan Givens from Alaska prepares a base for the
Page 35: Cob Oven Workshop with Tom Trout - United Diversitylibrary.uniteddiversity.coop/Ecological_Building/Cob_Ovens/Building_a_cob_oven-In...Dan Givens from Alaska prepares a base for the

Loading pizza.

Note the different colour spots from the torch tests on the oven side.

Page 36: Cob Oven Workshop with Tom Trout - United Diversitylibrary.uniteddiversity.coop/Ecological_Building/Cob_Ovens/Building_a_cob_oven-In...Dan Givens from Alaska prepares a base for the

Baking pizza. Floor temperature is around 600F and dome temperature 700F. Hearth is

cooler near the door, where cold air rushes in. Pizza in a wood oven is baked by radiation

from the

dome and conduction from the hearth. Cool air is streaming over the pizza itself.

Page 37: Cob Oven Workshop with Tom Trout - United Diversitylibrary.uniteddiversity.coop/Ecological_Building/Cob_Ovens/Building_a_cob_oven-In...Dan Givens from Alaska prepares a base for the

Post mortem.

The area around the door is quite soft, and abrades easily.

Page 38: Cob Oven Workshop with Tom Trout - United Diversitylibrary.uniteddiversity.coop/Ecological_Building/Cob_Ovens/Building_a_cob_oven-In...Dan Givens from Alaska prepares a base for the

Norbert Senf slices the oven with a diamond blade.

Page 39: Cob Oven Workshop with Tom Trout - United Diversitylibrary.uniteddiversity.coop/Ecological_Building/Cob_Ovens/Building_a_cob_oven-In...Dan Givens from Alaska prepares a base for the
Page 40: Cob Oven Workshop with Tom Trout - United Diversitylibrary.uniteddiversity.coop/Ecological_Building/Cob_Ovens/Building_a_cob_oven-In...Dan Givens from Alaska prepares a base for the
Page 41: Cob Oven Workshop with Tom Trout - United Diversitylibrary.uniteddiversity.coop/Ecological_Building/Cob_Ovens/Building_a_cob_oven-In...Dan Givens from Alaska prepares a base for the

Note the redder fired layer on the inside, and the darker intermediate layer where there is

charred

straw.

Page 42: Cob Oven Workshop with Tom Trout - United Diversitylibrary.uniteddiversity.coop/Ecological_Building/Cob_Ovens/Building_a_cob_oven-In...Dan Givens from Alaska prepares a base for the

Overall thickness is around 3" - 4".

Page 43: Cob Oven Workshop with Tom Trout - United Diversitylibrary.uniteddiversity.coop/Ecological_Building/Cob_Ovens/Building_a_cob_oven-In...Dan Givens from Alaska prepares a base for the
Page 44: Cob Oven Workshop with Tom Trout - United Diversitylibrary.uniteddiversity.coop/Ecological_Building/Cob_Ovens/Building_a_cob_oven-In...Dan Givens from Alaska prepares a base for the
Page 45: Cob Oven Workshop with Tom Trout - United Diversitylibrary.uniteddiversity.coop/Ecological_Building/Cob_Ovens/Building_a_cob_oven-In...Dan Givens from Alaska prepares a base for the