Textured paint finish after stripping wallpaper - any ideas why?

[AnnaM]

We’ve stripped our living room wall of wallpaper, underneath the plasterwork was good quality with patchy white paint on it. We’ve sanded the wall and applied some thin filler to smooth areas where the paint had lifted from removing the wallpaper. Even though the wall is completely smooth to touch when we apply paint it instantly has a texture to it, see pics. After the first coat of paint we sanded the wall again and got rid of the texture, but when we tried again the same thing happened. Any ideas why? We’ve sanded the wall so much. One person has mentioned damp but I though this would cause bubbling over time, not as soon as you apply the paint?

[stoneyboy]

Hi annam
Did you prime the repaired areas with a watered down coat of emulsion?
Regards S

[AnnaM]

Thanks for the reply and help.

No I didn't, do you think that is the problem? If so what might the solution be?

[stoneyboy]

Hi annam,
Lack of a prime coat using watered down emulsion seems the most likely cause. Sand down the wall to give a smooth finish, prime (the emulsion needs to be almost like water) and when dry apply another coat.
Regards S.

[AnnaM]

Thank you, I'll try that then.

Why would I use watered down emulsion instead of a shop-bought primer? Just out of interest

[stoneyboy]

Hi annam
Your aim should be to apply a coat of thinned paint which will soak into the new surface and give a good bond as well as reducing background suction. If you apply paint straight out of thin tin a high suction background will quickly suck out the water leaving just a poorly adhering surface skin.
Regards S