Bubbling old paint, unable to paint over

steveburns04 · Post by **steveburns04** » Thu Jun 11, 2020 5:58 pm

Hello

I stripped the walls in my living room of the wallpaper. Underneath was painted plaster in poor condition. I sanded it down as much as I could and used polyfiller to fill in defects. I tried applying paint however lots of bubbles formed from the old painted surface. I didn't realise that at the time so bought zinsser peel stop clear binding primer and used that, but bubbles still formed due it being the old paint and not the new paint causing the issue. I have removed the bubbled bits with a scraper and sanded them down. However I am worried other areas with bubble that didn't bubble the first time, so wondering wether re-plastering is needed in this situation? I have shown some pictures. The only before picture doesn't show the affected wall much, but it is the pink coloured bit above the flaked yellow part. It is much bigger areas then in the photo but this was the only one I had. Any help and advice is appreciated. Pictures are attached.

rozzleshnozzle · Post by **rozzleshnozzle** » Thu Jul 09, 2020 11:01 am

G'day! I am also suffering the same problem. I have removed old wallpaper, scraped it all down, have sanded the walls, including the old paint. I then went and primed the bare plaster, and found where the primer had dribbled on the old paint, it started bubbling. So I started scraping.. and scraping. It has taken me 3 full days. To get to the point of replastering the damaged areas, and now it's day 4, 11am and I'm about to burn the house down. This was supposed to be one room, done in a few days and now I feel like I'm about to go mad.
Did you find you just had to bite the bullet and scrape it all off?

wine~o · Post by **wine~o** » Thu Jul 09, 2020 11:12 am

Common problem. Unless all traces of wallpaper paste are removed ten as soon as you apply any emulsion the paste re-activates causing the bubbles. Lots of elbow grease, plenty if hot water and a scotchbrite pad to remove wallpaper paste (may need going over several times) Once you are happy that all traces of paste have been removed, let the wall dry thoroughly before painting.

2 other options.

Apply lining paper and paint that or

Apply a full coat of zinsser Gardz before painting.

rozzleshnozzle · Post by **rozzleshnozzle** » Thu Jul 09, 2020 3:06 pm

It happened to me on areas that as far as I know had no wallpaper. Would this indicate there probably was at some point ant the previous owner just painted over it?

wes56 · Post by **wes56** » Thu Jul 09, 2020 5:15 pm

I dont know anything about decorating but that looks like penetrating damp coming through the plaster.
Do you have outside render or CWI?

The only "cure" for that kind of thing is to knock off the plaster back to brick and redo it.

bitzz · Post by **bitzz** » Fri Jul 10, 2020 7:30 am

As Wine o says above, most likely to be wallpaper paste give a good wash down, dry then a good coating of Zinsser Gardz, then emulsion of your choice to finish.

Puma · Post by **Puma** » Sun Jul 12, 2020 1:15 pm

It might be old fashioned white wash. See if it will wash off.