Painting Problem

[expat paul]

Hi,
I have just spent a good day sanding and cleaning the previously painted ceiling (plastered) and walls (plaster bricks) in my bathroom. Late last night I tried to apply an 'sous couche platre' with a roller but old paint flaked off and either stuck to the roller or the new paint on the wall.
Anybody know why and the best method to cure the problem ??. I tried to scrape off the old paint but not much came away.
Thanks

[Aly (used to be Charlotte3)]

Hello Paul.

 

It sounds as if you have done all the right things.

I'm a commercial decorator and if this happened to us we would do the following:

ALWAYS use an oil based sous couche on bare plaster, any old undercoat or satin finish that you have hanging around will do, but make sure you thin it out really well (think milk!). Give everything a really generous coat, it's impossible to use too much, and try to ignore the bits coming off. When it's all dry sand off the bits that are stuck to the wall, and if you have shallow "holes" where they came off just fill in with a little enduit. When everything is sanded off again, coat the little bits without paint on them. Don't be too fussy, just slap it on.  If painting, sand down again to give a really smooth surface, or if papering just proceed as normal.

I think I've covered everything.....are the bits coming off really huge? If so try using a metal brush instead of sandpaper.

Any more problems just ask,

Aly

[expat paul]

Thanks,

I'll try that tomorrow [:)]

No the bits aren't massive but enough to clog the roller and either stay on or transfer to the wall, but I only did about 1m before I stopped in dismay. I was told on another forum thats its been possibly limewashed before does that make any difference ?

Paul

[Aly (used to be Charlotte3)]

Oh yes, it certainly does. Anything with lime in/on it will basically "eat" through whatever you put on top, hence the need to use an oil based product. All you can do is slap it on and hope for the best. It's always a problem here when painting over an old previously painted surface!

You could always go to your local brico and be sold something like alcalai resistant primerfor an exorbitant price, but really there's no need. If there was, we would use it!

The trick with this sort of problem is really to seal in all the old stuff so that it can't react with your new finish.

Are you going to paint the room? It sounds as if you might be better to paper it? Anyway, you know where I am if you need me.

Good luck, let us know how it goes,( at least with this c--p weather you may as well be indoors working, seeing as there's little chance of topping up your tan!)

Aly

 

[Dave&Olive]

hi

ok just had the same problem in the bedroom i have just done . The walls have been built with terracota brics and the paint came off in big sheets at the bottom ,I have found that sous couch stuff is a total waste of money and time ( but i could be using the wrong one ) but I had some pliolite oil based out side paint left over so I gave it a thinned downed coat of this first and he presto it worked, but there is an expert on site... 2 things I said I will never have when we moved here was wallpaper and carpet !!!

         Dave`s first day off in 3 months cannot believe I can get so pi**ed on 3 small glasses of wine [B]

[Aly (used to be Charlotte3)]

I take it you mean the "sous couche stuff" for plaque de platre.

What you've done is use an oil based product for a sous couche, which is exactly the right thing to do. You don't need to buy a dedicated undercoat for plaster. Different case for wood, though!

As for the wine, that's what happens when you "rest" you liver for a while.....mind you, makes the wine go further when you do start drinking again!!

Aly

[expat paul]

Thanks for the great advice, I painted the ceiling with a diluted oil based paint, covered really well, but I didn't have much left over. So, the walls, I got a tip from another forum about using a wallpaper steamer to strip off all the old paint, worked like a dream, so gave them a coat of diluted emulsion.  [:D]