[Cob] wood ashes and concrete

[Amanda Peck]

What holds up cob, mortar, adobe, etc. etc. etc. is the stuff that doesn't 
dissolve in water, isn't water, and doesn't crumble into powder on its 
own--i.e., nice sharp builder's sand (there's a nice discussion in a mystery 
story called Fault Line about desirable and undesirable qualities of 
different SANDS--why on earth would this be in a mystery story?  both the 
author--Sara Andrews--and her heroine are geologists--people either love or 
hate the series.).

So I'd guess that SAND could be the missing ingredient.

I can guess why the wood ashes are in there, not sure about the 
salt--although there's a fair amout of salt in many whitewash recipes.

........................
Lucynda Riley wrote:

  i found a recipie through a self sufficient living website I am a member 
of to make a type of concrete using salt, water, and wood ashes.  It 
actually worked pretty well.  I made a small dap of it on a cookie sheet and 
had to smash it with a hammer before I could break it loose.  Ofcourse it 
crumbled into pieces after that.  Through some experimenting i learned that 
its hard like concrete until you break the shiny surface on top, then it 
crumbles.  Its also becomes soft again once it gets wet.
  Is there anything I could add to it to cause it to not soften when it gets 
wet or to crumble into pieces once the surface is broken?



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