how to remove paint from old (1800) plaster walls?

[lizgiz]

I'm trying to get layers of paint off an old plastered wall without damaging the plaster underneath. The idea is to leave the surface of the plaster exposed. There's a couple of layers of paint that are peeling off in places but in other areas it's really stuck on. Dont want to rip into the wall with a scraper, dont want to damage plaster with a chehanksmical. Can any one offer any advice? Thanks

 

[opps]

not sure that it is possible with damaging some areas. A decent scraper and steam stripper might help but plaster that age might just crumble.

I would expect that someone would have used distemper at some point so another alternative might be to soak the wall with wallpaper paste (evaporates slowly) and then scrape once the paint has reactivated or softened.

You might be able to use a DA sander on the sound areas but often plaster that age has a lot of grit in it which will rip the plaster surface.

 

[lizgiz]

Thanks Opps, that was quick and expert! I'll try the wallpaper paste on a small area. Sorry to be thick, but what's a DA sander? My wall has layers of thhick flaking paint on the surface, but under that there are areas where something like much more watery paint has been used. This under layer is much more soaked into the plaster, like a stain rather than a paint, and I want to get the paint layer off to expose the old plaster with coloured bits, if you see what I mean. Does that layer sound like distemper? Thanks for your expertise.

 

[opps]

You should be able to wash distemper off with lots of hot soapy water or steam.

A da sander is a round disk sander.

I omitted to mention that a wall that age will have probably have been filled on previous occasions and thus you might not get the uniform finish that you want

Once stripped you might be able to sympathetically "colour wash" it to fake a uniform finish

 

[lizgiz]

Hmm, that's a thought. I hadn't considered filler. Reckon you're right though, it's bound to have been filled over the years. This started off as a quick redecoration job, now it's looking like archeology!

 

[oldgreymouse]

Just been reading your post and would like to add a couple of things to watch out for on old lime plaster.
If the house is as old as you think,'1800' then the walls are going to be lime plaster if they are still original, if more modern, then a little bit easier to deal with.

Lime plaster was made up by mixing a lime putty with whatever bulking material was available from the local area, coal dust, ash, furnace clinker, any grades of sand and most likely horse hair to bond it all together.

The problem you will have to watch for, is if you break through any paint surface into the plaster, it will start to break up as it will now be very very very dry!!! Once this starts to break up, you could end up with very deep and very dry holes which will be difficult for you to fill with diy fillers.
BIG trouble!!
Do not use a steam stripper as this will 'Blow' the surface off when the steam hits the lime mortar, it will make a popping sound as the wall breaks away inside.

I suspect you have found that some of the paint flakes off fairly easy from the paint surface that you have and that you want the wall to look all old and patchy rather than paint it over, if this is the case, just scrape off what you can and give it a coat of matt water based varnish.

 

[opps]

Do not use a steam stripper as this will 'Blow' the surface off when the steam hits the lime mortar, it will make a popping sound as the wall breaks away inside.

Good point- I forgot to mention that holding the plate in one place for to long would be a problem. Anecdotally, I have only ever blown modern skim coats.

 

[lizgiz]

I suspect you have found that some of the paint flakes off fairly easy from the paint surface that you have and that you want the wall to look all old and patchy rather than paint it over, if this is the case, just scrape off what you can and give it a coat of matt water based varnish.

Thanks for replying, it's much appreciated. You're right, I want a (whisper it on here) shabby, unfinished look. I might end up just stripping off a smallish area with a scraper and framing it somehow, since the wall seems to have many different bits of plaster, filler, paint etc on it. Not surprising given its age I suppose. I don't think it's lime plaster though, can't see any hair, although it does have a rough texture. I suppose the wall may not have been plastered at the time it was first built, it was a brickworks not a house originally. I'd better stop mucking about and "planning" and actually get on with it.