Painting my stained ceiling

[noclue123]

Hi,

My ceiling has quite a few small stains - splashed from plastering and rendering work done on my walls about a month back. The ceiling is smooth after some sanding. I did actually start painting round the edges with emulsion but stains were showing through so I stopped.

What is the best way to hide those stains before painting over with emulsion? I do not want to be applying a stain blocker that leaves a glossy finish as it'll be a nightmare to paint over with emulsion (I've had that experience before when I used Bulls Eye 1-2-3 water soluable primer).

I have heard that I could use some kind of undercoat first then use emulsion to do the trick? Basically I want to hide the stains and have a matt finish.

Help!

 

[Robbie uk]

Just use a thinned down coat of oil based undercoat. This will allow the emulsion to cover it without being seen when its all dry.

 

[noclue123]

Cheers. But how much should I thin the undercoat - perhaps 1 part water to 1 part undercoat?

 

[benno5]

needs to be oil based undercoat mate thinned with about 15% white spirit

 

[noclue123]

thanks. Just to confirm, I can apply the thinned undercoat just over the stains - rather than covering the entire ceiling?

 

[Robbie uk]

Yes just the stains.