Paint and old wallpaper paste

[endecotp]

Dear Experts,

I am renovating my living room. Most of the walls have new plasterboard which I will paint. But there is one bit of wall that is plastered brick which I’m not sure what to do with.

Currently it has painted lining paper over the plaster (apart from a bit where it meets the new plasterboard, where I’ve stripped the lining paper). I’d like to end up with a painted surface that matches the new painted plasterboard. The surface has various dints and scrapes but it’s not terrible.

One option is to strip the paper, sand and fill the plaster, and paint. Another option would be to hang new lining paper over the existing. Or I could just sand and fill over the existing paper. What do you reckon?

One unknown for me is what happens if I attempt to paint over the old paster with the remains of the old wallpaper paste. How bad an idea is that? I can attempt to remove it with e.g. sugar soap but will that be sufficient?

Thanks.

 

[Wayners]

Dried paste you can neutralise with gardz.
I normally use a orbital sander with 120 grade discs to remove dried paste then gardz to seal residue. Just a better way.

Either get the paper off or new lining over but use ready-mix paste to stick lining as less water and higher stick.

Other option Is to use zinnser bin to seal then paint. Stops it bubbling up.

So you have options

 

[endecotp]

Thanks Wayners. I’ve now removed the old lining paper. There is now a layer of old paint over the plaster, except where it came off with the paper. I plan to give it a sand, fill any holes, and then paint. Question: when painting on bare but old plaster, should I be using a diluted mist coat? Or is that only for new bare plaster?

 

[Wayners]

All paints come with a data sheet online.
Thats will tell you application and preparation.
Durable scrubbable emulsions are different to standard vinyl matt sometimes with how you prep walls.
Can work out better to use products like gardz or use a matching tinted acrylic primer first.

I definitely would not use a contract matt as a primer as it's very dry and chalky

 

[endecotp]

Thats will tell you application and preparation.

It’s a vinyl matt which I’ve used successfully on new plasterboard, diluted per instructions. It says “on new dry plaster or other highly-porous materials….”. This is old, dry plaster. So not new dry plaster, so I don’t dilute it?

 

[Wayners]

That's the easiest one. Vinyl matt works well as a mistcoat