What is the "ready mixed" lime mortar you can get from people like Tilcon or RMC
and how does it differ chemically from lime putty mortar?

all the suppliers' literature I've seen seems to assume it is going
to be mixed with cement on site.

This website shows what I mean:
http://www.mortar.org.uk/wm_hom01.htm

The mix which this company sells is probably hydrated lime and sand.
When the cement is added, there is just a normal cement set, with the
lime acting as a plasticiser for the mix

But had the cement not been added, yes the ready mix is chemically
similar to lime putty mortar - just add water -

As well as this cement ready mix, it is also possible to get two other
different sorts of REAL lime ready mixes

Lime putty and sand readymix I use all the time. Comes by the bucket.
Take the hard graft out of mixing, just add hair, fluff up and go

The other is hydraulic lime mortar in big hoppers. This generally gets
used for newbuild

Anna












I've not heard of either of these brands which make me think that they
must be hydraulic lime mortar

Just to confuse everyone, there is hydrated lime which is dried bagged
putty lime

And there is hydraulic lime which is lime putty with impurities in
notably silicon check this. Hydraulic lime always comes as a dried
powder never as a putty cos one of the effects of the silicon is to
make it set underwater.

Another effect is to make it set quicker

Another effect is to make the final plaster harder; a bit more like
cement which is a BAD THING

There are weakly hydraulic limes and strongly hydraulic limes
~~ Anna Kettle, Suffolk, England
|""""| ~ Plaster conservation and lime plaster repair
/ ^^ \ // Freehand modelling in lime: overmantels, pargeting etc
|____| www.kettlenet.co.uk 01359 230642