Natural (clay) plaster recipe

[Eric D. Hart]

Hay folks:
        Here's a recipe for a clay based plaster from Robert LaPorte (the
guy who does straw/clay-what Patrick is doing in Georgia now).  From what I
hear, the final coat should be fine for interior applications (won't rub off
with every day use) but if used on the exterior it needs a small top coat
added every 3 or 4 years because the plaster literally erodes off the wall.
I still hope to try this recipe out on a strawbale display we did here in
Minneapolis.  Instead of 'mining' clay from my garden, we bought two bags of
Hawthorne Fire Clay.  This is the cheapest clay available (normally used for
pots, etc.) and it also has the lowest shrink swell potential.  The cost for
a 90 lb bag is about half that of portland cement. We bought it at a pottery
supply company.   Its a fine powder that has a very nice soft feel to it.  

Natural Plaster, (from Robert LaPorte's Moose Prints)

Rough Coat:
	1 part creamy clay slip (from site or mixed water and clay)
	2 parts medium sand
	1/2 part fiber (chopped straw)
	
Finish Coat:
	1 part creamy clay slip (from site or mixed water and clay)
	2 parts medium sand
	1/2-1% oil or eggs (by volume)
	fiber optional


Eric Hart
Minneapolis, MN