[Cob] (no subject)

[yew]

"Jilly" wrote:

>What do you add to the plaster 
>mix to get various colors? 

It depends on what you're using for plaster.  Earth-based plasters can be 
colored with mineral and plant pigments (including things like dried blood), 
while lime-based plasters work better with mineral pigments (the alkalinity can 
bleach plant pigments).

Make sure any mineral pigments you use are non-toxic.

>The books I have are conflicting 
>about treating earth walls...

I think most warn against using cement-based plasters, but as long as the 
finish is fairly permeable, it should work fine.  Here in the PNW, I'd 
definitely use a lime plaster of some kind to help prevent moisture damage 
while still allowing the walls to breathe.

Here's a link to one of my favorite stores in Seattle--they offer powdered 
pigments for just this purpose:

www.environmentalhomecenter.com/shop.mv?CatCode=PRODUCT&ProdCode=O_O_PIGMENTS

Brina