Franz Heymann wrote:
:::
::: 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

Yes but this is unlikely to be replaced soon, if you ask a plasterer to save
any sand/lime chippings you will soon have a few CWT for the garden...it
melts if left in water for long enough...the odd bit of gypsum won't do the
garden any harm if it's mixed in with the older stuff.