Victorian Cornice - stripping, sealing?

[RenoGal]

Hi
Couple of questions for anyone knowledgeable in victorian plaster;
I'm renovating a 120yo glasgow tenement, currently just stripped the mediumly ornate cornice & rose using stream and unsure how to proceed...all suggestions greatly appreciated!

What is victorian cornice made of/finished - ie: assuming plaster but what are the below layers likely to be?
there are several layers, from external layer on top:
- paint,
- light brown mud-like? (often very thick in places, was in all the grooves/ details etc)
- darker brown thin layer?
- clean brightish orange, almost wood looking, layer showing through in some places - is this the base plaster? - (so far its only come through on the straight sections)


The stripped ornate sections look great & I want to leave them stripped and 'rustic' ie: brown.


but on the straight sections flanking the ornate cornice, the brown layers are flaking - (assuming due to the steam).

- ? Any suggestions how to stablise the flaky brown surface? or do i need to strip this further before finishing. (and if so any suggestions on easy method?)
would a chalk based paint work better? something like earthborn?

- ? And thoughts on whether victorian cornice needs to be sealed (or similar) long term? or can be left bare (baring in mind i dont intend painting)
Dont want it to dry and crumble or anything over time.
(- wondering whether a soft wax might seal and give an interesting finish - like the annie sloans stuff)

Ceiling & Distemper
While I'm asking - the ceiling around it - which i will paint, is in mixed condition. I've stripped the lining paper and its got a few cracks and stippled surface in places, but hopefully seems stable. I was going to get it skimmed but the Plasterer reckons its distemper - its yellow white silkish paint, grey beneath and assuming its over lath - so skimming might not be best anyway.
So looking for a quicker, 'rustic' fix to get the job done, if there is one......?
I've seen a thick 'no more cracks' ceiling paint - anyone used it? any good?
whats the latest on distemper - will any of the modern paints stay over distemper? - or one of the interior sealers I've seen mentioned on here first?
or again would a chalk paint work better?

Many Thanks!

 

[mayti]

have you tried washing with sugar soap

 

[raggles]

The top layer of plaster on the cornice is more than likely lime putty the dubbing out plaster behind that will be a lime based plaster ie lime mixed with sand and fibres (horse or goat hair). As for the finish of the mouldings to me it looks like it has been originally painted to resemble wood maybe or shellac possibly ? if you like it that much it's possible a water based clear varnish may stabalise it but then again may not without actually seeing it in the flesh so to speak it would be hard to say. The dispemper on the ceiling would have to be washed off using a sugar soap solution to give any new decoration the best chance of adhering this would be time consuming as you need to ensure all traces of distemper are removed before progressing.

Oh and welcome to the forum

 

[johniosaif]

Porridge works a treat on it, try put it on warm, not too hot or cold.

 

[RenoGal]

Hi Mayti thanks for responding
- yes using sugar soap on ceiling at the minute. tho probably should try the cornice again with it. cracked cornice surface seems to soften and blend a little while i am using a waterbased on it but then it dries back and cracks on drying. thats why i was wondering that soft wax might give it enough moisture to hold it together and shine/ protect the surface - weird product for cornice though i know.
might try again the sugar soap again.
thx

 

[RenoGal]

interesting detail...thanks raggles, i will investigate that further. Tho I have to say none of the layers look like they have sand - at least not course sand. The thick light brown layer looks more like clay or mud to me - very much the colour of the chocolate cream layer on a penguin!
when you say 'top' layer - do you mean closest to the original mouldings or closest to the paint?
so do you think the bright orange is the original plaster mouldings?

...loving learning about old buildings, their history and their structure....just need to get this project moving again in the meantime!

 

[RenoGal]

lol! thanks johniosaif - being in scotland i tried porridge.... twice. maybe i didnt have the consistency or left it on too long or something, but i couldnt get it to work well for me....steam on the other hand was amazing! - steam also worked wonderfully on my wood panelling - which really has come up a treat.
but thanks for the idea.

 

[raggles]

interesting detail...thanks raggles, i will investigate that further. Tho I have to say none of the layers look like they have sand - at least not course sand. The thick light brown layer looks more like clay or mud to me - very much the colour of the chocolate cream layer on a penguin!
when you say 'top' layer - do you mean closest to the original mouldings or closest to the paint?
so do you think the bright orange is the original plaster mouldings?

...loving learning about old buildings, their history and their structure....just need to get this project moving again in the meantime!

Yes closest to paint is top layer and as far as i can tell from the pics they look original

 

[Arti]

im sure ive seen on one of sarah beeney's shows they use a paint stripper type compound /gel what they painted on and left it for 24hrs and it brought all the gunk off

 

[flynnyman]

Yes your right arty and oasis done something similar but I'm not gonna try and find the post but @Nisus probably has it in his files