Blistering primer over emulsion

[Sparrowhawk]

First time I've had this issue so hoping someone knows what's going on.

 

I've skimmed two rooms with jointing compound to get rid of orange peel finish, sanded smooth and primed Leyland acrylic primer undercoat.

 

In one room 3 walls are fine, and 1 wall has this issue. In the other room 2 walls are having problems.

 

For the room with one wall having issues:

I applied a diluted coat of Leyland acrylic primer to seal the plaster, sanded with 240 grit, and then one coat of Tikkurila Optiva 3

The colour was far too strong so I sanded and put on a coat of Leyland acrylic primer with a roller to start neutralising it (hoping for better coverage than a standard white emulsion).

And randomly across the wall I'm getting blisters, from under 0.5mm to 3mm+ across. Sometimes singly, but the smaller ones in groups.

 

They flatten a bit as the paint dries but don't go flat. If I sand them off it blisters in the same place the next time.

 

I've tried thinning the primer, to see if that helps (it doesn't)

I've applied multiple coats and the bubbles keep happening in the same spots.

 

I'm ready to blame the paint as the walls I did with Tikkurila didn't have this problem. But neither did other walls I painted with primer.

 

What do you think?

 

Photos while it's still wet

 

 

And once dried:

 

 

 

Room 2 was the primer undercoat directly onto a mix of skim & original emulsion. Same issue.

Edited March 2, 2023 by Sparrowhawk

[gaz_moose]

i had this happen from leyland trade waterbased stuff from screwfix once when painting internal doors. id come to the conclusion it was excess water. i found going over them lightly with a damp brush got rid of them. having damp brushes/rollers before you start seems to help.

[Spreadsheetman]

We just had a similar-ish problem where the previous owners had slapped a coat of blue satin kitchen paint over original satin paint. Anything we did over the top (including a coat of Zinsser bullseye123+) caused bubbling when further coats were added as the blue wasn’t properly stuck and moisture penetrated through it and made it lift.

 

The only solution was to manually wet and scrape as much of the blue satin off as would come and then coat it all with Zinsser cover-stain which is solvent based. This worked and we could then paint normally over the top.

[Sparrowhawk]

Thanks @gaz_moose and @Spreadsheetman. My situation turns out to be identical to yours @Spreadsheetman. Some kind of contamination on/in the wall and yes I tried bullseye123+ first and it still bubbled.

 

Zinsser cover-stain has sorted it - save I missed two areas and have to redo them! I ended up thinning it by 30-50% with white spirit as it was impossible to spread smoothly otherwise; at a guess because the wall is porous and absorbing liquid.

[Discoeye]

General dirt and grease from your hands can make the paint react this way, the roller trail looks a little heavy to so a medium pile or short pile sleeve and take it gently.

[JohnMo]

Why are you using acrylic primer in the first place? To prime a wall just use emulsion watered down 20 to 25%. Then emulsion over with undiluted emulsion, once dried. Job done

[Temp]

On 02/03/2023 at 21:33, Sparrowhawk said:

For the room with one wall having issues:

I applied a diluted coat of Leyland acrylic primer to seal the plaster, sanded with 240 grit, and then one coat of Tikkurila Optiva 3

The colour was far too strong so I sanded and put on a coat of Leyland acrylic primer

Perhaps see..

https://www.tikkurila.co.uk/faqs/blistering-on-water-based-paint-film

 

 

[Sparrowhawk]

On 28/04/2023 at 10:13, Discoeye said:

General dirt and grease from your hands can make the paint react this way, the roller trail looks a little heavy to so a medium pile or short pile sleeve and take it gently.

A finish as smooth as I'd like still eludes me with a roller, even adding 10-15% water there's more stipple texture than I want.

 

Upstairs I'd mist coated some old but bare plaster (long story) which went on fine, then at the weekend put the first coat on. The wall was more absorbent than I thought it'd be and while coverage was good it's dried looking like 400 grit sandpaper. Be nice when I master this skill and don't have to keep sanding back.

Any recommendations? I'm using an Allpro short pile (3/8" knap IIRC) microfibre roller sleeve, and trying to put on the paint, work it over the wall and then lightly roll off in one direction.

Edited May 3, 2023 by Sparrowhawk

[Sparrowhawk]

On 28/04/2023 at 13:12, Temp said:

Perhaps see..

https://www.tikkurila.co.uk/faqs/blistering-on-water-based-paint-film

I'd thought it was the chemical reaction one as after skimming the orange-peel paint from the previous owners and sanding back, there are points of the original wall paint that come to the surface. But Optiva primer had the same problem, so it wasn't that.

[Sparrowhawk]

On 28/04/2023 at 12:54, JohnMo said:

Why are you using acrylic primer in the first place? To prime a wall just use emulsion watered down 20 to 25%. Then emulsion over with undiluted emulsion, once dried. Job done

This house came with a lot of strong colours on the walls. I started overpainting using Johnstone's trade brilliant white from Brewers but got fed up with the number of coats. I read online that the Leyland acrylic primer would cover better so gave that a go. I've now switched to Tikkurila Optiva primer which is far nicer to work with than the previous two - and is designed for this purpose. But I've run out of the very strong colours to overpaint so haven't a fair comparison of its covering power.

[JohnMo]

I started using Dulux trade paints a few years ago.  Not cheap but good covering power. For anyone interested B&Q, and Screwfix and other outlets are way cheaper than Dulux trade centres.

[SteamyTea]

On 02/03/2023 at 21:33, Sparrowhawk said:

What do you think

Are the walls the same construction?

May be a problem with them, rather than the paint i.e. damp and cold.

[Discoeye]

Most will probably disagree but Hamilton perfection 12 inch medium pile{ green sleeve} load the roller up and use every last drop on the wall before reloading and don't take to roller off the wall until you need to reload.