Dealing with easy peel paint (no mist coat used on fresh plaster)

Joined
4 Nov 2010
Messages
6,045
Reaction score
620
Location
Cumbria
Country
United Kingdom
Situation (as if you'd not already guessed) :
Extension built about 10 years ago (by previous house owner). Paint appears to have been applied to fresh plaster without a mist coat. So with very little provocation it peels off. And now we're re-decorating - doing some alterations (extra sockets etc) along the way.
It's not going to be practical to peel all the old paint off, but there's areas missing now (especially where I've been hacking out the wall for cables etc. Other than generally sanding things down as best we can, any other suggestions ?
The biggest problem with sanding (I'm using a belt sander) is that it tends to pull up the edges of what's left rather than feather it off. But there's areas we need to sand down to get the wall flat as the plastering "isn't very good" and there's lots of "blebs" from him having tried to work the plaster while still too wet.
 
Sponsored Links
Joined
3 Sep 2015
Messages
309
Reaction score
5
Country
United Kingdom
We recently had the same problem. Was just one wall though. I used one of the 'American'/heavy duty scrapers (carefully!) and a steamer.

Did a mist coat then filled with Tourpret. Just sanded it back today actually. Due another mist coat again me thinks. Then top coats.

I did use knauff jointing compound or skim and fill to cover /Bridge missing bits before, worked okay but I'd have preferred to scrape all off really.

Some would say decent thick lining paper may be the answer too. I'm a bit naff with paper so didn't go down that route
 
Joined
3 Sep 2015
Messages
309
Reaction score
5
Country
United Kingdom
We recently had the same problem. Was just one wall though. I used one of the 'American'/heavy duty scrapers (carefully!) and a steamer.

Did a mist coat then filled with Tourpret. Just sanded it back today actually. Due another mist coat again me thinks. Then top coats.

I did use knauff jointing compound or skim and fill to cover /Bridge missing bits before, worked okay but I'd have preferred to scrape all off really.

Some would say decent thick lining paper may be the answer too. I'm a bit naff with paper so didn't go down that route
 
Joined
16 Jun 2006
Messages
7,484
Reaction score
1,507
Location
London
Country
United Kingdom
There are number of ways to deal with it.

As @ChilliBob says, you can use a steam stripper. Steam strippers can blow skin coats over old horse hair plaster if you are not careful though.

Sometime I roll a coat of wallpaper paste over the wall. It evaporates slowly, allowing the water to penetrate the paint. It then scrapes off easily. You will however need lots of polythene to pick up the goo.

One more one occasion I have applied a coat of emulsion and then noticed that it hadn't been misted. I then used my Olfa scraper to remove the whole lot.

For the record, Olfa, a Japanese company make gorgeous scrapers. They also make blunt flexible blades that won't dig in.

Alternatively, you can seal the whole wall with shellac based paint. The water in the emulsion will not penetrate through it.
 
Sponsored Links
Joined
4 Nov 2010
Messages
6,045
Reaction score
620
Location
Cumbria
Country
United Kingdom
As it happens, I've been experimenting a bit more today. Of course, the original plastering is so ... poor ... that using a scraper is fiddly as it misses all the dips and I find I have to go every which way, plus tilt the scraper at times, to get everything.
SWMBO noted that where I've applied a cost of colour using sample pots, it's blistered in places - before going down flat again as it dries. She has a better memory than me and says it was the same when we painted the kitchen (also part of the extension). So I gave the steamer a go, it seemed to make a little difference, but using it means either 3 hands, or using the big scraper (I have something similar to the Olfa 12" scraper) single handed which is ... not easy. I probably need to give the steam longer to soak through - at times I lack patience :rolleyes:
The hot air gun didn't work - it softened the paint to the point where it didn't scrape off easily as it had gone "gooey".
So on the whole, not much difference between scraping as-is and after a good steaming.

Now, flexible blades, sounds interesting.
 
Joined
3 Sep 2015
Messages
309
Reaction score
5
Country
United Kingdom
Ah man that sounds grim. All the bloody little bits get everywhere too! Carpet, skirting etc!

Perhaps the WallRock lining paper is a better option? I think you might want to use zinsser Gardz on it first but look into that, it's a hunch from reading about it for other reasons if mine.

The bubbling is odd though, again if you stick to getting everything off perhaps use Gardz instead of a conventional mist coat - supposed to be good for problematic surfaces.

Oh, and with this scraping route, do be careful not to dig the wall! My wife had a go near the bottom thankfully and I think she found the process a bit annoying so she went at it a bit hard! Some Tourpret seems to have sorted it mostly thou
 
Joined
30 Jun 2008
Messages
15,506
Reaction score
1,803
Location
Suffolk
Country
United Kingdom
How about some wet & dry abrasive paper to feather off the edges of the loose bits?
 
Joined
16 Jun 2006
Messages
7,484
Reaction score
1,507
Location
London
Country
United Kingdom
The paint bubbling and going back is common when the wall hasn't had a mist coat. The bigger problem is when you are rolling the wall, the suction created by the roller often pulls the paint off.
 
Joined
4 Nov 2010
Messages
6,045
Reaction score
620
Location
Cumbria
Country
United Kingdom
Oh, and with this scraping route, do be careful not to dig the wall!
Yeah, been there ...
The problem with this wall is that it's so uneven, the scraper just rides over the low spots, so there's no option but to work with one end of the blade. I've just ordered some of the Olfa flexible blades Opps mentioned, with any luck they'll work better.
How about some wet & dry abrasive paper to feather off the edges of the loose bits?
Haven't tried that, but using regular abrasive, especially in a powered machine, pulls the edges up and leaves them ragged - lack of adhesion problem. And I'll be going over the wall with the belt sander to take off the "blebs" - in places, and depending on the light, it looks like a teenager's acne.
The paint bubbling and going back is common when the wall hasn't had a mist coat. The bigger problem is when you are rolling the wall, the suction created by the roller often pulls the paint off.
Just as I'd managed to put that horror out of mind, someone had to remind me :eek: Yes, had that in the past.

Another thing that don't work :
Hot air gun. There's a fine line between softening the paint enough to make it easier to scrape off, and turning it into something soft and sticky that's very much not easy to scrape :rolleyes:
 
Joined
16 Jun 2006
Messages
7,484
Reaction score
1,507
Location
London
Country
United Kingdom
Another thing that don't work :
Hot air gun. There's a fine line between softening the paint enough to make it easier to scrape off, and turning it into something soft and sticky that's very much not easy to scrape :rolleyes:

Heat guns are useless with waterbased paints.

Emulsion paints are pretty much impossible to feather out properly when sanding. Part of the problem is that the plaster is much softer than the paint.
 
Joined
4 Nov 2010
Messages
6,045
Reaction score
620
Location
Cumbria
Country
United Kingdom
For the record, Olfa, a Japanese company make gorgeous scrapers. They also make blunt flexible blades that won't dig in.
Many thanks for that recommendation - the flexible blades did indeed make life a lot easier.
The name didn't job my memory until I looked at their website and saw the Touchknife they do. At a previous job (a good few years ago now) we had loads of them around. I'd assumed they were something cheap given that we literally had bags of them, but I do recall that I used one for ages - really sharp, kept it's edge, but eventually the plastic gave way to wear & tear.

Anyway, to follow up. The plasterer* came yesterday to fill in my chases - so just waiting for the plaster to dry before I can get finished.

* I decided that getting someone in with the right tools and knowing how to use them would be quicker than my rather hit and miss attempts :rolleyes:
 
Joined
4 Nov 2010
Messages
6,045
Reaction score
620
Location
Cumbria
Country
United Kingdom
Finally, got it all painted/papered, electrics sorted, and the furniture back in place last week - so got it "done" in time for Christmas as instructed by SWMBO :D SWMBO is generally happy, but pointed out that using silk paint makes all the poor plastering show up if you look even a bit closely. As long as you don't look too closely, people are impressed.
20221214_175012.jpg



Then next year I'll have to tackle the disaster of a floor :mad:
 

DIYnot Local

Staff member

If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.

Select the supplier or trade you require, enter your location to begin your search.


Are you a trade or supplier? You can create your listing free at DIYnot Local

 
Sponsored Links
Top