[Cob] Fire Bricks, Ovens, etc.

[ocean]

Well researched posting, Jon!

In our commercial cob oven, Kiko used firebrick for the base (cooking 
surface) then built the dome of the oven out of a mix of clay and grog 
(pulverized fired clay) to avoid spalling.  You can see pictures of the 
oven and a sequence of Kiko building it on our website at 
http://www.intabas.com - just click "Maya's Home Page"  Kiko also made 
use of "refractory cement" to form a pumice-crete entry arch to the 
oven; this is a form of Portland cement with a very high alumina 
content.

Ianto also used firebrick as the back panel of a Rumford hearth he 
helped us build in the cob Kiva at Ahimsa Sanctuary.  The firebrick 
both conducts and reflects the heat into the thermal mass and into the 
room being heated.

This said, there is also another kind of firebrick available, which I 
believe is made with pumice (judging on how light it is).  This might 
be used when building a chimney or fireplace and wanting to insulate 
surrounding wooden frames.  So you must specify whether you want 
"refractory" or "insulating" firebrick!

Ocean Liff-Anderson
Intaba's Wood Fire Eatery
http://www.intabas.com
Ahimsa Sanctuary
http://www.peacemaking.org


On Jun 2, 2005, at 1:26 AM, Jon Kerr wrote:

> Hi Gang!
>
> Does everybody know about Wikipedia? Free online encyclopedia, 
> http://wikipedia.org
>
> My personal experience with firebrick is that there are numerous types 
> ( I bought mine from Smith-Sharpe Firebrick supply in minneapolis, and 
> they had several choices/prices depending on how hot a temperature you 
> wanted them to withstand).