Disaster preparing painted walls

[johno12345]

Hi,

Im decorating my bedroom for the second time since i moved in.

Some parts of the wall have blistered, i think this was damp as the house was left empty for a few years beforehand. I have scraped this off no problem but now on the other walls, where im filling using a lightweight filler, the paint is coming off. it goes soft and peels away from the old paint underneath.

I think that if i paint tomorrow using water based paint, it will bubble and ruin the finish. should i be sealing the existing surface beforehand? and what with?

Thanks

 

[Username1]

have you cleaned the walls with sugar soap before painting?

 

[johno12345]

i havent painted yet! just filling the holes

 

[jondecs]

What filler? onetime?
I prefer polyfilla (interior).. Sometimes the substrate becomes friable when filler is applied to crack.. might try priming the area to fill with either solvent undercoat (thinned with white spirit) or some zinsser 123. (waterbased) Apply filler let dry then prime filler with dilute emusion then try a coat on 1 wall first.

good luck..

 

[johno12345]

its polyfilla one fill, i have just put some unibond on the wall and the old paint is bubbling up.

might have to skim it. might give lining paper a go first.

turning into a mammoth job now

 

[Robbie uk]

Do not use PVA before painting with emulsion paint.

 

[johno12345]

i have put lining paper on it now, 1700gsm, well started it anyway. looks like ill get a good finish with it when its all painted.

thanks for the help