[Cob] building with stones, was: Re: composition of clay mortar for urbanite

[Amanda Peck]

I'm kind of notorious on this list for thinking that working with quicklime 
is a "kids, don't try this at home" substance because of the heat of the 
reaction and the possibility of spattering when you slake it.  If something 
takes protective equipment I'm not sure I want to deal with it.

But if you were slaking it in a damp sand environment, the quartz sand (not 
coral--limestone--sand) might spread the reaction out and make it a bit 
safer.
..................
"Predrag Cvetkovic"  wrote (snipped)

I wonder about quartz too. As I've found, its melting point is about 1600 C
and lime slaking temperature is only about 160-210F (max. 100C). What can be
the role of quartz? Or we can omit it and make hot lime mortar:

"Hot Lime Mortar (only suitable for building) is produced by adding
Quicklime (Lump Lime) to damp sand. It has small lumps of lime in it, which
can often be seen in old mortars. It is good for general building but should
not be used for plastering/rendering or pointing. " (from the web)