"Phil L" wrote in message
.uk...
Mike Lyle wrote:
:: Robert wrote:
::: "Franz Heymann" wrote in
::: message ...
::::
:::: "Robert" wrote in message
:::: ...
:::::
:::::
::::::
:::::: If you want real lime, try a builder's merchant, especially
:::::: one who sells lime mortars.
:::::
::::: Builder's lime is a different thing altogether and is inactive
::::: on the garden.
::::
:::: That is quite incorrect. Builders' lime is Calcium Hydroxide,
:::: known as "slaked lime" It is an alkaline material which is
very
:::: frequently used to treat acid soil.
::::
:::: [snip]
::::
:::: Franz
:::
::: ps Slaked lime is not builder's lime, slaked lime is gardeners'
::: lime. Builders' lime is hydrated lime. So we are as one even
::: though we didn't know it lol. Merry Christmas Franz
::
:: Surely this can't be right? Calcium hydroxide is calcium
hydroxide,
:: whether you call it hydrated lime or slaked lime. You can't use
:: gardeners' lime to make mortar, but I thought that was just
because
:: the builder's version was "sharper", by virtue of being fresher
and
:: so not as thoroughly slaked. But you can certainly use builders'
:: lime in the garden, though it washes out, and isn't safe for the
:: skin by any means (it kills slugs): I'd use ground chalk or
:: limestone.

You can use gardeners lime to make mortar.
They are both the same basic compound, except for gardens it has
been slaked
and then dried, builders (who still use it) slake their own, IE:
drop it
into a dustbin full of cold water, wait until it stops boiling, then
use as
normal...slaked means it has been added to water to take the fire
out of it,
after this process it can be dried and doesn't need to be slaked
again
before use, this is what you buy as gardeners lime.
If you find a plasterer and ask him to save all the old plaster
rmoved from
old houses (not cement) it is a mixture of sand and lime (and
horsehair)...it breaks up the soil nicely and raises the alkalinity
too.

Nowadays indoor plaster is more likely to be based on calcium sulphate
(gypsum) rather than calcium hydroxide or calcium carbonate.

Franz