Cob heat storage

[Michael Saunby]

> Hi Folks,
> 
> this is a bit off topic, so I hope it won't develop a long thread. For quite some time now I've been trying to find appropiate (what's that?) phase change materials to store heat gained by a solar collector. Parrafins are great, but expensive and flamable (ever lit a candle?). Inorganic salts are corrosive, other materials are toxic, expensive, ... Where is the one I want? It should be in the 100-170 F range, cheap, easy to obtain, and safe (though I know that nothing is perfect). Anybody knows of such a material or where to look for it? Any advice that helps me forward is greatly appreciated.
> 
> Uwe
> 
> 

Just browsing through some old messages and gave this some thought again.
I know it isn't cheap and is also flamable, so this isn't a solution as
such, more a case of lateral thinking, but beeswax liquifies in a solar
collector.  This is a common method used by beekeepers to melt down old
combs for reuse, candle making, etc.  Bees make the wax themselves and
other creatures also exude waxy substances (ear wax!).  

However, other than beeswax I can't think of a commercially available
wax so perhaps animal or vegetable fats would work.  Whale blubber is
probably hard to obtain and not very P.C.  but  with the fashion for
low fat diets there must be a suitable animal fats available very 
cheap.

Hope this is of some help.

-- 
Michael Saunby