Anna Kettle wrote:
On Thu, 18 Sep 2008 12:32:24 +0100, Rod
wrote:

Wood I can understand, but why does plaster need covering? Its not
flammable

The answer to my own question is that plaster is not flammable, at
least not at the temperatures which will surround a woodburning stove.
Plaster is basically rock and needs to be heated to significant
temperatures before it changes state


If you are thinking lime plaster (and that would be expected!), I don't
know. But for gypsum the temperature is quite low and could easily be
achieved round a wood burner.

"Gypsum rock is converted into gypsum plaster by driving off some of the
chemically combined water. Heating gypsum at 120°C for one hour results
in a hemi-hydrate (CaSO4.1?2H2O) €“ with three quarters of the water
removed. Gypsum hemi-hydrate is also known as Plaster of Paris.
Prolonged heating over several hours results in the formation of
anhydrite with practically none of the chemically combined water left."

http://practicalaction.org/practicalanswers/product_info.php?products_id=305

--
Rod

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onset.
Although common it frequently goes undiagnosed.
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