Paint over plaster patch - how to blend?

[experience]

I have added some wall sockets and added plaster & filler to the surrounding areas to make good. A few days later sanded down and painted with a couple of coats of trade emulsion, however I'm getting a 'lip' around the patch area which makes the patch stand out.

I've sanded the area down again to make sure its perfectly smooth and tried painting again with a couple of coats with the same 'lip' results.

I think by repeatedly sanding I've worn the area away of the surrounding plasterboard so am making it worst.

The only other thing i can think of is to sand down again and use plaster sealer, let it dry and then a couple of coats of emulsion?

Patched

Cropped

• experience
• 29 Dec 2016

1st time painted - surrounding 'lip' highlights patch

IMG_9339

• experience
• 29 Dec 2016

Sanded down again

IMG_9341

• experience
• 29 Dec 2016

Painted 2nd time (2 coats)

IMG_9342

• experience
• 29 Dec 2016

Lip present again

IMG_9343

• experience
• 29 Dec 2016

 

[sparkwright]

I would agree the edges need 'sealing' before the emulsion goes on.

What have you painted the bare sanded areas with? Ordinary emulsion or thinned emulsion?

Watered down emulsion should be good enough.

Maybe some oil-based undercoat will seal it together better.

Any 'papery' bits of plasterboard should be filled over. Any tufts of paper need cutting back as they can push out.

I think the problem is where the plasterboard has been sanded it's left an exposed edge to the plasterboard, which soaks up the paint.

It should be noted though that emulsioning over oil-based paint can leave a difference in paint colour, which tends to sort itself out when fully dried, after a few days or so.

When it's all painted and you get the lip back, have you tried simply applying some filler around the lip, without all the excessive sanding? It may well be that you are trying too hard.

Maybe worth trying this first before sanding it all back to bare plaster again, though of course we can't actually tell exactly how raised that lip really is.

Is the wall skimmed, or is it bare plasterboard that was just painted?

 

[sparkwright]

The very first picture you sent looks like it should accept the paint. Did you sand after this before applying the paint?

I would say you want the surface to be more like the first picture, without all those exposed sanded edges like the other pictures show.