Dave Liquorice wrote:
On Tue, 15 Jun 2010 19:34:11 +0100, newshound wrote:

I've used a needle gun on mine, but of course it doesn't do a very big
area.

Ah the voice of experience. B-) A PW jet doesn't do a very big area
either.

To my mind, if the gun won't take it off you can paint over it.

That would be my sort of thinking as well. The mechanical whacking
acation aspect being one up on the PW. How long did it take to clean
down say 1 sq m of fairly loose paint?

I'm repointing with lime mortar and painting with home made lime wash.

I know one ought to use lime mortar/lime wash on a random stone but
we are *very* exposed and the existing pointing is cement based. In
the interests of not having to paint/patch repoint every few years I
don't think lime mortar and lime wash are up to it over cement mortar
and a modern breathable paint.

If you're using portland cement and stone then its non porous so why
have a breathable paint?

One reason for lime mortar is that it's softer than stone,
so if the building settles then the pointing gives way, rather than the
stone cracking.

It may be a good idea to use a softer sand with portland cement.
so that it will give rather than the stone crack.

perhaps

[g]