Paint reacting to wall

[marsaday]

I painted a lounge yesterday and it was an old house with plaster walls. I was just redoing the magnolia.

The paint has bubbled in many places and i wondered what is the cause of this reaction?

I have had it before in this room. Do i need to strip back the old plaster ?

Or is there a treatment i can appy. Most of the bubbling will settle down, bu i will need to sand off the worst of it and paint with a brush in these places

 

[Bosswhite]

I painted a lounge yesterday and it was an old house with plaster walls. I was just redoing the magnolia.

The paint has bubbled in many places and i wondered what is the cause of this reaction?

I have had it before in this room. Do i need to strip back the old plaster ?

Or is there a treatment i can appy. Most of the bubbling will settle down, bu i will need to sand off the worst of it and paint with a brush in these places

Did you paint over the original Emulsion Finish, Being an old House I would guess that the walls still have some of the Old Distemper finish on them or been sealed with PVA, and have been repainted with Emulsion, depends on how bad it is, you could clean off the bubbles, fill with fine surface filler and spot emulsion.

 

[marsaday]

yes i painted over the origional walls. not sure what was on before. There was a green paint previously and i had to sand this down in places a few yrs ago.

 

[Bosswhite]

yes i painted over the origional walls. not sure what was on before. There was a green paint previously and i had to sand this down in places a few yrs ago.

If you wet your finger rub the green paint and it comes off onto your finger then it is probably going to be old distemper finish, that would be your problem its unstable for covering with emulsion.

 

[marsaday]

yes it you get green hands when touching it.

I will google what this dietemper finish is as never heard of it before.

 

[Bosswhite]

yes it you get green hands when touching it.

I will google what this dietemper finish is as never heard of it before.

Sounds very much like Old Distemper Finish (very Chalky and Friable)
A messy job getting rid of it, you can try washing the walls off, but this is not very successful, (or steam Wallpaper Stripper)
Your best bet is to apply a coat of Stabilising Solution to the walls, make sure the room is well ventilated.
Stabilising solution is like a very thin varnish that soaks into the distemper and binds it to the wall, make sure the floor and everything else is well covered as it will drip and splash everywhere. Very messy, good luck !!!

 

[dcdec]

Zinsser bin is very good over distemper but because itys shellac based its expensive and very smelly. Gardz will do the job it will bind and seal the walls.