lime mortar tech

["Charles Kibby" <ckibby@zzzzzzzzzzz>]

Lime mortars need exposure to the atmosphere to cure, in order to complete
the chemical process.  Mortar laid in the interior of a large wall would run
a good chance of not being fully exposed to the air and thus not fully
cured.

My last time at an ATP conference, I had a conversation with a conservator
who had worked in the U.S. Capitol Architect's office and he told me that
when they had opened up an older section of the Capitol Building facade,
they discovered old lime mortar around the Aquia Creek sandstone blocks that
was still somewhat pliable.  Makes sense, if the blocks were quickly laid
and the interior portion of the bedding mortar encased completely before it
could fully cure.

Linseed oil has been used for many things over the years to make stone and
masonry walls more weather repellant, but I have not heard of it being used
as an additive to lime mortars prior to installation.

chaz

My main interest in discussing lime mortars of old, is to try to verify
comments that I have heard elsewhere. I have ran into a few references of
masons pulling set stones in ancient castles and finding the mortar to be
still pliable. I have not been able to observe work of this type and I am
very interested in hearing from those who have dealt with it. Is it true?
Since the mortar is so soft was the structure sealed in its entirety with
oiled sand, or was this strictly a treatment for wet areas of the wall?