Painting over hairline cracks

[Hooch]

I have a wall which is criss-crossed by hairline cracks - not deep enough to fill. How should I prepare this wall for painting so that the cracks don't show through afterwards?

thanks in advance for any suggestions.

[Ryan]

Hi Hooch,

I don't know what other on the group feel but I've always found Polycell BaseCoat to be good for this. I've used it a number of times in a friends house where this was a problem and the cracks have never come back .... well not yet anyway :-) I know the other school of thought is to widen then crack so you can use filler and then smooth it off.

So far I've used both methods and both seem to do the job properly.

Hope this helps Ryan

[Steve]

To do a good job you need to open up the cracks and make them V shaped.

I use an old 1" wood chisel which does the job quickly and neatly.

Steve

[Mary Fisher]

I recently painted a ceiling which is covered in cracks. I masked them by putting a bare run of acrylic sealant from a gun along the cracks then rubbing gently with a wet finger along the crack to smooth it off. It took some time but the effect was great. The first thing designer son did when he went into the room was look up to criticise my attempt but even he had to admit that he couldn't see a trace of any crack. That was some praise!

Mary

[chris French]

In message , Hooch writes

I use fine surface filler - comes ready mixed in tubs or tubes. As suggested by the name it is fine textured and will fill fine hairline cracks without the need to make extra work for yourself widening them out.

Wipe a thin layer into the crack with a flexible filling knife, it dries pretty quickly as such a thin layer, then just sand lightly with fine paper.

[visionset]

IMO If the cause is due to blown plaster ie it isn't connected to the wall anymore, then by all means fill them by any method. But more will appear quite quickly. Tap for hollowness to test. If the cause is subsidence then just live with it. If the cause is new build settlement and building dryout, then widen crack and fill as per other posts. This advice applies to hairline cracks only.

[robert]

PolyCell paint on crack filler works remarkably well - worth a try. Robert

[Hooch]

Thanks for all the replies. I've bought some Polycell Basecoat (expensive!) and I'll give it a go.