How can I solve my paint cracking problem?!

[jb72]

Hi,

I've recently, after months of nagging, started to redecorate our daughters room. I think I may have rushed the first 2 coats on one wall though because the next morning there were loads of tiny cracks all over - possibly the first coat hadn't fully dried. Two subsequent coats later and things have improved a little (although I may be kidding myself) - if I keep painting will the cracks eventually disappear or do I need to do something else?

I'm so nearly done and all the other walls look great - help - how can I solve my paint cracking problem?!!!!

Cheers,


jb72

 

[misterhelpful]

There are several things that can cause this:

Painting over a greasy or dusty surface, walls cleaned with chemicals, old wallpaper paste, PVA or even using different finish paint to the original are just a few. Applying the paint too thickly and drying out quickly can also cause this issue.

Are any of these possible reasons in your case?

The problem isn't always easy to solve, but one way that often works is to sand the surface as smooth as possible, dust off and apply an oil based undercoat before re-painting with your finishing emulsion. Not guaranteed but usually successful.

Another way is to use a fine surface filler/onefill over the crazed areas with a wide bladed filling knife and sand smooth before painting again.

It is unlikely that just applying more coats will solve the problem but you might be lucky and find it does.

 

[jb72]

Thanks.

A few years back we stripped the wallpaper, then had it re-skimmed, then sealed it and painted - all about 2-3 years ago. Just got round to redecorating now and this happened. The cracks are, as you say, crazed areas and not deep - would a good thick basecoat work e.g. Polycell Basecoat? Anything to avoid filling and sanding!!!

 

[misterhelpful]

I would imagine it should, but it's not something I've tried.

If you do try this, let us know if it's successful so it can be added to the list of possible remedies!

Cheers

BTW, did you seal the plaster with PVA as it may not cause problems initially, but can when re-decorating, ie now?

 

[jb72]

Just saw your question about the PVA - the answer is yes, I sealed after plastering with waterered-down PVA on the advice of our plasterer!?!!

 

[misterhelpful]

Just saw your question about the PVA - the answer is yes, I sealed after plastering with waterered-down PVA on the advice of our plasterer!?!!

The reason for your problem then is because the PVA re-activates when the paint wets it. As it then dries, it shrinks and causes the crazing.

Oh dear, even more proof for the non-believers out there that PVA isn't suitable for use with paint.

It may well be worth a shot with the Basecoat then, but if it still occurs you could try Zinsser Gardz which is useful for sealing problem surfaces, although I'm not sure about PVA.
http://zinsseruk.com/shop/Product.aspx?cId=130&pgId=359