Paint "washes" off walls

[Bon]

Hi guys,

Every wall we have painted in our house seems to suffer from the same problem. When we try to wipe off marks with a very slightly damp cloth, the paint comes off the wall and the marked area looks worse than it did in the first place and leads to the area having to be re-painted .

We're shortly going to be painting the kitchen once its been re-skimmed and I've read on here that special "kitchen" paints are a bit of a swizz so we'll be using normal emulsion. I was wondering if anyone can point out what we're doing wrong as with it being the kitchen we're more likely to need to wipe spills etc. from the walls.

Our normal painting procedure goes something like this,

1. Remove any odd lumps from the newly plastered walls
2. Apply one coat of Polyfilla "basecoat"
3. Apply 2 coats of neat paint.

 

[JohnD]

is your house a fairly new one where the walls are still painted with Magnolia Matt or whatever builders use these days? if so it is probably a non-vinyl Trade Supermatt intended for new damp plaster, and not the same as you will be using.

Or, if you redecorated yourself, what sort of paint did you use last time?

First coat of emulsion on bare plaster or filler should be thinned with water to give a "mist" coat that soaks in and seals the surface. instructions will be on the tin.

I don't see the point of your basecoat.

If you want a very hard-wearing paint you could use Eggshell which is an oil paint, but you must be sure the plaster is fully dry first, and ventilate very well while applying.

I am just a householder.

 

[Zampa]

I agree with JohnD...i cant see the point in the base coat either..

Couple of points though...eggshell isnt only oil based it water based to..thus, very little smell, quick drying and non yellowing etc.

To use an oil based eggshell on plaster walls could lead to problems with paint defects...the would need to be coated with an alkali resisting primer first...which is probably one of the one paints that give me a head ache and bad throat because of the fumes.

 

[Bon]

Our house is approx 120 years old.

The basecoat we use was recommended to us to stop hairline cracks from showing through. Although you say it's pointless to use, will it be doing any harm?

Not after a particularly hard-wearing paint, just one that will allow us to occasionally wipe off the odd mark. I'll find out the exact type of paint we have used in the past but from memory its been standard Dulux stuff.

 

[JohnD]

Our house is approx 120 years old.

then there is probably distemper on the walls, and maybe traces of old paste.

distemper is quite difficult to clean off, it dissolves in hot water but not cold and needs a lot of scraping when soft. Scrubbing helps but also just spreads it round rather than taking it off.

is the old plaster at all powdery? your poor adhesion might be caused by a problem surface, plus you have not been using a mist coat.

p.s. don't put PVA on a wall before paint.

 

[Bon]

OK thanks for the advice John & Zampa.

Will use a mist coat on the newly plastered kitchen walls instead of the basecoat stuff.

Do the successive coats need to be thinned down at all or do they go straight on?

 

[JohnD]

some people (me) like to appy a second thinned coat, especially if the first one soaks in fast and disappears. If the surface is very dry and hungry you will feel it sucking the moisture out of the paint as you brush it on and this does not give a good result.

 

[joe-90]

All paint needs to be thinned unless you want brush marks and roller stipple.

That's the best decorating tip you'll ever get.

 

[Bon]

Just been lloking on the Polycell website and the procedure for applying the basecoat contains a line I've never noticed before

Seal new, bare and porous surfaces with a suitable plaster sealer

So as I have not done this, would I be right in assuming the basecoat and the subsequent coats of emulsion would be affected and be the cause of my problem?

 

[Growler]

All paint needs to be thinned unless you want brush marks and roller stipple.

That's the best decorating tip you'll ever get.

Rubbish.

 

[54aardvark]

So as I have not done this, would I be right in assuming the basecoat and the subsequent coats of emulsion would be affected and be the cause of my problem?

More than likely, if you have very dry walls/new plaster, it will suck all the moisture out of your paint so it doesn't adhere propery. Mist coat is the ideal solution, dilute your first coat of non-vinyl emulsion by 40% then go on with full strength - personally I dilute my subsequent coats by about 5-10%, this allows the paint to flow better and means you are always working to a wet edge, thus minimising roller/brush marks.

 

[Bon]

OK guys, thank you very much for the advice

 

[Bon]

Right I've now done the mist coat in the newly skimmed kitchen. I used Dulux trade vinyl matt and have since discovered (after reading on here) that I should have used non-vinyl however I have also read posts stating that on very dry plaster/a thin skim vinyl is OK(?)

I thinned it down with water by approx 20% and did the ceilings and walls.

I've just tried rubbing with a damp cloth and it's washing off as per my previous problem . Giving it the once over with 120-grade paper has also removed the paint in some parts, but these are where there are high spots in the plaster.

I am now worried that when the top coats are done, I'll end up with the same problem.

So, have I done something wrong or is it that the mist coat is purely to give a non-porus base onto which the top coats will adhere and I'm just being paranoid?

 

[confidentincompetent]

Im wondering just how hard you are 'wiping' ? Any emulsion if you rub too hard will eventually break down ..especially with damp cloth. TBH the time to worry is if the emulsion becomes powdery i.e wipe over wall with palm of hand, is your hand coverd in dust from the emulsion? If not and you can scratch over with your finger nails without tearing the emulsion you have won You shouldnt abrade tooo hard, just a light rub over to de nib or missed defects..
Emulsion takes 30 days to cure and achieve full hardness.
Sometimes with Matt emulsion its easier to touch the mark up with some left over emulsion you saved. (hopefully)

Good luck..

 

[Bon]

Hmm, I suppose i was rubbing with a little vigour(!).

Running my nail over it doesn't scrape it off so hopefully it's OK. As said in my first post in the other rooms we've done any sort of damp cloth removes the paint with ease.

Fingers crossed it's sorted then!

Thanks again for all your help.