On 09/08/2019 21:31, Vir Campestris wrote:
On 09/08/2019 07:55, Jim K.. wrote:
Vir Campestris Wrote in message:
On 07/08/2019 14:45, Martin Brown wrote:

If it is an acrylic based sealer it will fail the same way. You may
need
a thin skim of plaster across the whole wall to bury the offending
lime.

I put a well-watered-down coat of ordinary emulsion over our new lime
plaster, and I've had no trouble.

Andy


New...

If the alkalinity is the problem why would old lime be worse than new?

Probably because the original stuff wasn't really as well mixed as it
should have been and some bits are very alkaline. If you were only ever
going to use a lime wash on it then there isn't a problem.

Modern organic polymer paints don't get on with some of the very old
limewash type surface finishes that were used in the pre-1900's.

--
Regards,
Martin Brown