Selective paint stripping

[PlywoodPascal]

I know PH is maybe more often home of the shiny shiny rip it out board it over type approach, but will ask this question anyway.

I’ve done some picking at the walls in the hallway of my house. There are a lot of layers of paint. Or possibly wallpaper of some sort.

Wallpaper
Pinky paint (modern emulsion)
Pale Green paint (modern emulsion)
Brown/cream/yellow stuff (older paint)
Dark green finish
Original plaster

I think the dark green stuff might be distemper and date from when the house was built.

If I did want to remove all the paint except the final (or first!) layer…. How might I go about it

(In test patch, this has been scraped off mm by mm…)

[OutInTheShed]

I would try the effects of a steamer and various scrapers.

A lot may come off quite easily, if layer 2 is not well bonded to layer 1.

In my first house, I ended up using a hot air gun to get some remnants of paint off of plaster, but I would not fancy doing big areas like this.

A lot depends on the nature of the plaster, it can be tough or soft. Sometimes hot water and a scouring pad shifts a lot of emulsion.

[mart 63]

I wouldn't use a steamer on old walls, it will pop the plaster in places. Just use lots of hot water with fairy liquid, and keep soaking the walls.

[JoshSm]

If that's distemper then it wouldn't survive a removal plan involving water or steam as that'd be pretty effective at removing distemper too!

Selective removal *maybe* with a chemical stripper, if you could find one that you were sure would soften a more modern paint but not the old one, otherwise it's going to have to be carefully doing it mechanically.

It's not a robust finish and if the later paint is properly bonded it could be fun trying to retain just that layer..

[PlywoodPascal]

thanks all.

yeah steam/hot water would take out distemper. I think if it is, it is oil bound. it gets a bit darker with water on it. it does wash off a bit with water, not a lot. I have not checked with hot water.

the dichloromethane stripper I used didn't really touch the green paint, which is good but it's a bit unpleasant to use.

since I wrote the post I've learnt that if an oil paint was intended to be used on plaster, if it was new, it was often painted with a distemper and left for a while for the plaster to cure before painting. otherwise the alkali fresh plaster would saponify the oil in the paint.

fwiw, a steamer on the lime plaster is, my experience, pretty ok. it's not like gypsum, it doesn't go soggy so much. I have used a steamer to strip a load of wallpaper that was directly onto the same plaster and it has been fine. bit the plaster is in good shape and not blown. even then though, if anything, getting the lime plaster a little damp can help stick crumbly bits back together.

so it looks like careful chipping it off may be best option. Although I still need to test the various layers of paint to see if they're lead containing (almost certainly), which would indicate a chemical stripper would be better than a mechanical method.