[Cob] Glass impregnated wood timbers

[ocean]

Kiko and I have used waterglass extensively to seal earthen plasters.  
The substance is called sodium silicate, and is available at pottery 
supply houses.  Potters use it in a kiln to seal the shelves, 
preventing "spalling".  This is a toxic substance when in its liquid 
form, so adequate protective gear is needed when applying it (gloves, 
eyewear, etc.)

Contrary to Ed's post, waterglass provides a breathable, porous surface 
(similar to limewash).  This is why it works well on our earthen 
plasters, and I speculate it could be applied to protect wood.  I don't 
think it would work well for sub-soil posts, which would be in constant 
contact with water and insects, etc.

I've told people we coated the cob wall at the restaurant with 
waterglass, and on more than one occasion a former mechanic said he 
used it to seal cracked engine blocks!  Also, it has been used to 
preserve eggs for years.  (Kiko - do you have anything to add?)

Ocean Liff-Anderson
_____

Steward, Ahimsa Sanctuary  http://www.peacemaking.org
Proprietor, Intaba's Kitchen  http://www.intabas.com


On Nov 12, 2005, at 7:08 AM, Raduazo at aol.com wrote:

>
> In a message dated 11/12/2005 10:01:44 A.M. Eastern Standard Time,
> ap615 at hotmail.com writes:
>
> Joyce  wrote:
> Does anyone have any information or web sites to reference about a  new
> timber product I saw on TV (This Old House maybe). The timbers were  
> coated
> with a glass product of some type, heated to a point where the glass  
> melted
> into the wood and provided a protective coating that could be  stained 
> -
>
>
>
> The melting point of glass is far higher than the combustion 
> temperature of
> wood. My feeling would be that this is not possible, however there is
> something  called waterglass, a silicon compound that is dissolved in 
> water and when
> dry is  very resistant to re-hydration. It has been used for coating 
> earth
> products, but  I think it may have problems in that water which 
> penetrates through
> cracks in  the finish can not evaporate.
> Ed
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