to get back on subject . . .

[Tomas Lipps <tmlipps@zzzzzzzzzzzzz>]

weren't we talking about walls, flexibility, linseed oil stones, mortar?
Ian Cramb in "The Art of the Stonemason"*- "Boiled linseed oil is
linseed oil so treated that it absorbs oxygen at a much increased
rate, and thus becomes converted into a tough skin or solid in less
time. The process is brought about by heating the oil to a high
temperature and is increased by the addition, during the heating, of
certain substances known as driers.

I have used boiled linseed oil as a pointing material on exposed
joints, and for sealing stone from pollution.  Mixed with mastic
sand, it is an ideal sealant between stone and any other material. It
is much used as a pointing material around doors and windows. In
building stone during the industrial period and in building railroad
stations in cities, each stone was coated with (or immersed in**)
linseed oil before being set in position. This protected the stone
 from pollution penetration."

one wonders how those structures have endured by comparison with
masonry otherwise treated, or untreated. . . if the mortar was
likewise treated, . . would it guard against grafitti?

*out of print, difficult to find , and expensive-but soon to be
republished by Taunton Press!  or so I've heard.
**as Ian mentions elsewhere.

T

p.s. c'mon guys, be polite.  this isn't a "reality" show.