About to Lime Plaster

[N. Thornton]

Hi

Have made some lime putty and tested it: works great. Now, having never plastered before I have a question. If I mix sand into the putty I presume the sand is gonig to stop me from being able to get a surface flush with the surrounding existing plaster. It only takes a few grains to stray over the top of the old plaster to make a perfect level join impossible.

I have a feeling this train of thought is wrong... any input?

Oh BTW, I made it from a bag of hydrated lime that was opened 5 months ago and stored in a dry place - and it works great, no deterioration problem. Thanks for all the help on this one!

Regards, NT

[Anna Kettle]

Congratulations!

For a fine internal finish use a 3mm deep layer of 2 silver sand : 1 lime putty

Bung it on and then scrape the junction level with a straight edge (eg piece of wood) pressing on the the old bit of wall as a guide, then let the plaster set a bit. Once it has an initial set then repeat with something finer - the proper tool is called a joint rule which is a flat rigid piece of metal with an angle on the leading edge, but I expect you can improvise, maybe with the edge of a trowel. Then clean up any bits of mortar which have strayed onto the old bit with a small paintbrush and water.

Lime mortar shrinks as it sets so a) add as little water to the mix as you can, maybe none. b) Don't level it down perfectly too early in the process.

Good luck; I'm sure you'll do fine - there is plenty of time for adjustments unlike with gypsum plaster

Anna

~~ Anna Kettle, Suffolk, England |""""| ~ Plaster conservation and lime plaster repair / ^^ \ // Freehand modelling in lime: overmantels, pargeting etc |____|

01359 230642

[N. Thornton]

Thanks Anna, very helpful. Getting silver sand before I need to get this finished is going to be a problem though. I need to go think.

Regards, NT