[Cob] Lime putty on cob and adobe.

[Dirtcheapbuilder-Charmaine Taylor]

   Shody Ryon wrote:
  I know a lot of people mix lime and cob, but if the
soil has an acidic pH (very common) do they (the lime
and the cob) react aganist each other, reducing
structural integrity? Wouldn't it be more sound tech
to isolate lime and cob with asphalt emulsion?
++++++++++++++



Shody   What do you mean?.. all 3 will react together to bind the mass 
of clay.


I have mixed all 3, and you get a waterproofing element with the AE 
when a small % is added. as is done with adobes ( see my  last LONG 
post sent to cob list)

Lime will change the chemistry of clay to  alter its water absorption-- 
permanently, and AE added to clay will coat the clay to add 
waterproofing ability ( water shedding), all 3  is just another version 
of Run-R-Slate which has added shredded cardboard ( or paper)  hummm  
Papercrete anyone?

I have heard that too much lime wil make the cob crumbly.. at least 
that's what I undestood.. maybe  B Steen wrote about it? anyone 
remember?

The lime changes the  clay in its abiltiy to HOLD water molecules, and 
does not cause structural integrity.

I describe it as HOOPSKIRTS.. some clay has up to 79 hoopskirts that 
can fill with water.  ( the severely cracked riverbed clay is this 
kind, also known as Gumbo for Gumbotil clay)  When lime is added it' 
kicks off'  the hoops forever, and leaves a slimmed down clay molecule 
unable to swell up again.

Kaolinite clay has few water hoops, naturally, and does not swell or 
hold much water.

  there is no need to mix lime and AE...AE needs to be added last to any 
mix, or kept covered tightly or it will give up its water content and 
"dry" out.

  Charmaine Taylor Publishing
www.dirtcheapbuilder.com
Tel:  707-441-1632
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