Testing plaster to see if it is lime

[skier-hughes]

I remember reading in a post about testing plaster with I think vinegar to see if it was lime or not.

I have to find a route for the electricians to put their cables, or rather my new cables and I have got so far round, but on removing the old plaster I have found some old timber framing which is too far back to really look at closely, so I thought I could chip a small amount of plaster away and test it, before hacking it all out and regretting it!!

But I can't find the post, so don't know how to test it, anyone give me a clue?

Some of the timber framing has been filled with gypsom plaster, and I can't be sure just because this was hidden behind the newer plaster that it hadn't been changed when they did some building work back in the 1950's.

Graham

 

[biffvernon]

Lime is more likely to fiss with vinegar than gypsum is. Add a few drops and see if there are lots of little bubbles forming.

 

[skier-hughes]

Definately lime.....

As I tried to take a small sample out a piece about an inch square came away, nicely hairded and unfortunately the wooden lathe is very rotten.

Now I need to completely re-think my wiring route before the morning!!