paint/dec advice please!

[happyhippy]

Hi all,I'm hoping someone might be able to offer us some advice re a job we need to do.Ok,when we moved into our house 2 years ago,the loungeroom walls looked fine.After about 6 mths we noticed that the paint on some of the walls was flaking off.Initicially we thought maybe this was caused by damp so we had a surveyor check it for us and,fortunately its not damp.He said is was caused by not bonding the walls properly before painting.I've never heard of this bonding business and to save some money we thought we might try and tackle the job ourselves.So........do we need to scrape off every bit of paint on the walls first?Do general hardware stores stock this bonding stuff we need and how much is it?Is it an easyish job to do?Once we re bond,how long afterwards until we can re paint over it?Any advice would be really appreciated,thankyou!

[Odsox]

Pretty much the only real solution is to scrape it all off. If you get an edge of the paint layer and wet it with water it will probably lift, and if it does it will do that with the next wet paint coat. You can remove large areas by simply wetting it.
Bonding is needed on fresh plaster and can be as simple as giving it a first coat of emulsion that has been watered down, or you can give it a first coat of Unibond or other PVA. Either way there are instructions on the tins as to the dilution for fresh plaster.
Good luck.

Just noticed your other question.
You can repaint as soon as the bonding is dry, probably an hour or so.

[Maykal]

Obviously it's hard to advise without seeing the wall first but the surveyor is probably right. When you say 'flaking', what exactly do you mean? Are there elongated slits appearing in the paintwork from which the flaking is beginning, or are they more irregular flakes (say, like flaky skin)?

You say the walls looked fine when you moved in, so I'm guessing that the previous owner gave them a once over not long before putting the property on the market to make the place look fresh and clean, but perhaps without doing the proper prep work first.

Lack of bonding can mean too things, normally. If the house was recently replastered, then the walls are normally extra-absorbent, and this sucks some of the liquid out of the paint meaning that you don't get a good enough bond from the coat of paint. Normally, they should be washed with a compound that soaks into the new plaster and provides a good surface for the paint to key into.

The other way you get bad bonding is when already-painted walls aren't properly prepared for a new coat of paint. Grime, grease, calcamite, or oily/waxy substances (including oil-based paints) on the wall can stop the new paint (particularly latex paints) getting a good grip - remember when you were a kid and you drew pictures on paper with a candle and then painted over it?

Assuming it's quite bad, then yes, the best thing to do would be to scrap the paint off the wall, repair any damage, sand the wall down, apply a sealing/bonding agent, and repaint. If it's just the odd flake here and there, you can try just sticking it down with some sealing compound and spot-painting it, but that'll just delay the inevitable...you'll probably have to redo the wall in the end.

[happyhippy]

Thankyou for the advice,very much appreciated!As far as the flakes look,hmm its abit of a mix to be honest.Some of the flakes are elongated and some patches are very small flaky looking bits???One wall in particular,we have half scraped off the paint and it was pink untouched plaster underneath,and the surveyor showed us this pink section of wall was "dusty"and he put a wet finger on it and sure enough it was white dust,which he said we would have to wipe off first before doing any prep work.So what would we ask for at the hardware store?A sealant?Or bonding agent or are they the same things?

[baldybloke]

Unibond PVA adhesive. Dilute it down roughly 1 part PVA and 5 parts water. Give it a stir and paint it on. This will soak into the dusty plaster and will seal it. Then paint over it when dry.
As for the flaking paint, peel or scrape it off.

[happyhippy]

OK an update!We scraped as much off as possible,sanded it over,have applied the pvc(watered down as instructed on container).We have emulsion and paint,so do we emulsion the walls first,or can we paint straight over the bonding,and skip the emulsion bit?I just want to do the job properly and not have to deal with flaking paint in 6 mths!lol Thanks for any help,much appreciated!