[Cob] cob stoves & light straw

[Charmaine Taylor]

Hi Amanda and all...I was just reading an old JQ article with a correction to
the one Frank Andresen wrote ( shown in the link below)  dry CLAY weights in at
1000-1500 per c/ft.  But when a clay slip coats the chips of the the straw the
weight--in the wall- dry --is at 300-500 lbs per c/ft.

so there was a misprint in that article.

In any case I would keep a thick thick layer of cob between any woodchip/straw
wall, and the fire source.

In the ROCKET stove designs they recommend the wood ash itself as the insulator
between the walls of the tin cans to make the best insulation, or crumpled tin
foil..using the least mass to prevent absorption of heat, so the most heat goes
to the cooking.


Ms. Charmaine  Taylor/ Taylor Publishing
http://www.dirtcheapbuilder.com
http://www.papercrete.com


Amanda Peck wrote:

>
> One of the classic articles on clay-coated organic matter--this one was
> wood-chip--claims this:
>
> "Depending on the system you're using, the weight ranges from 1000-1500
> lbs/cubic yard of dry mix. The insulative value for a 12" exterior wall with
> plaster can be up to R-25, depending on the quality of the woodchips, clay,
> and the density with which the mixture is packed. Vapor barriers are
> unnecessary because of clay's inherent property as a diffusing water
> reservoir and the capacity for moisture dispersal."
>
> That's from: http://www.foxmaple.com/proclay.html
>
> I don't know what that claim is based on, whether it applies directly to
> straw as well.  I did see a lot of "dependings" in the sentence.
>
> .....................
> Brad asks Two unrelated questions:
>
> 1.  Does the inside of a cob oven become fired, like pottery in a kiln?
>
> 2.  Does anyone know the typical density and R-value of dry light straw,
> also how wide the panels can be compared to their depth.  Or can anyone
> suggest where such data might be found? (light straw = straw soaked in a
> clay soup, then packed densely to fill spaces, clay acts as fire retardant
> and mould inhibitor).
>
> _______________________________________________
> Coblist mailing list
> Coblist at deatech.com
> http://www.deatech.com/mailman/listinfo/coblist
>
> _________________________________________________________________
> Stay informed on Election 2004 and the race to Super Tuesday.
> http://special.msn.com/msn/election2004.armx
>
> _______________________________________________
> Coblist mailing list
> Coblist at deatech.com
> http://www.deatech.com/mailman/listinfo/coblist