Painting Fresh Plaster Woe - Advice Needed

[planemad]

I have had a room skimmed and left the plaster to dry out for around 3 weeks and it was completely dry and pink.

Yesterday I started to give it the first coat of Crown Contract white matt paint mixed with 30-40% water.

The first coat went well except for one small patch where the paint just will not dry and looks like its only on the surface and has not sucked in like the rest of the walls.

Today the small patch had still not dried so I scraped it off and sanded down the surface to try to get a good key, but this has still not done the trick as paint will still not stick to it.

Any advice Would be greatly appreciated

Many Many Thanks in advance

 

[Richard C]

If the plaster fully dried & pink before you painted, it would seem to rule out damp so I can only assume it's some sort of contamination. Could be excessive use of PVA & this has completely clogged the plaster in that spot but the paint should have dried eventually. Maybe it's some other form of contamination such as silicone or oil but why I’ve no idea; do you know what the plasterer used/did during his work?