[Cob] test & mix quicklime

[dirtcheapbuilder-Charmaine Taylor]

Robert VC-- please tell us how YOU did it too pelase since you were 
successful....

  There is a basic tennant on  chemistry stuff.

Do as you OTTA add ACID to WATER.  so ALWAYS add LIME to WATER

  in a clean container..and yes I love the 32 gal rubbermaid or other 
sturdy totes with lids.  It's easy to bend over and  get mix out... a 
50 gal drum means leaning way over to get to the bottom eventually..not 
good for short people, and you get lime in your armpits.

So always add the lime to a pail  or tub of water...not the other way  
around.

Hydrated lime will not exploded on mositure contact, but quicklime 
can... the danger is that is will go for ANY moisture..that means your 
eyes, nostrils mouth... so that is why it is considered dangerous.

Dave Cull a Canadian artist and user of Stonehemp..-his own  mix of  
hemp and quicklime putty.... told me he started a fire in a cement 
mixer because there was still some moisture in the mixer.. he added 
some dry quicklime and it burst into flame for a few moments..

++++++++++++++++++++++++
OK now that  your are warned here is the deal.


  to TEST the quicklime  you  ( just this once) put lumps or dry QL into 
a clean pail.  Add water carefully and slowly.   stand back   if it is  
feeble is will take 30 minutes to fully bubble and turn to a milky wet 
mix. If it is highly active it will "boil" and turn to a wet mix fully 
in 5 minutes.

this tells you how 'hot' the quicklime is.        always have clean 
running water ( a hose at the ready) and  pails of water for dousing.

TO SLAKE
Always use a solid metal or wooden trough.  Put the water in first...  
wearing complete protection add the powder quicklime to the water 
slowly while someone ' hoes' the  mix... it will begin  to "boil"-- 
this is an exothermic reaction releasing heat and  steam..  not 
anything toxic.

then just let it sit.

See ASTM C5 X1 for the best directions on fully testing and  slaking
and Lime is SLAKED only once. when the chemistry is taking place.. 
after that any hydrated lime you put into water is SOAKED
>
>
Charmaine Taylor Publishing    books at dirtcheapbuilder.com
PO Box 375 Cutten CA  95534 USA  -- 707-441-1632
www.dirtcheapbuilder.com  &  www.papercrete.com


On Jan 12, 2005, at 12:31 AM, ocean wrote:

>
> Calcium Oxide or "quicklime" (CaO) is a a very different material 
> which liberates a huge amount of kinetic energy/heat when "slaked" 
> (i.e. mixed with water) If not slaked/hydrated properly, quicklime can 
> burn holes in plastic barrels or even explode, covering you with very 
> caustic lime and blinding you if it gets in your eyes!
>
> Please, Charmaine, could you describe the proper safe way to hydrate 
> quicklime?  I'm nervous about how little we natural builders seem to 
> know about this dangerous material...
>
> Thanks,
> Ocean
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