Plastering

[paul_round]

We've just had our kitchen ceiling replastered and now it's been that it's painted, there are a couple of areas that look like oily patches underneath the paint. The plasterer has told us to paint over the offending areas with undercoat, (which we have done) then repaint over with the white emulsion that we painted the ceiling with, but these marks have reappeared, we have now done this process twice to no avail, any suggestions as to how to sort this problem?

 

[jbonding]

were the patches there before the ceiling was reskimmed? try painting over the patches with gloss paint let it dry then emulsion over this might work.

 

[paul_round]

No they weren't, it was artex that was skimmed over. If I try gloss, will emulsion work over that?

 

[Zampa]

No they weren't, it was artex that was skimmed over. If I try gloss, will emulsion work over that?

No it wont....you will have adhesion problems, try stain block instead, there are many brands on the market.

My theory, when you first mentioned 'oily' patches were marks caused if the plasterer polishes the surface to much making it impervious...if there were no stains before that could be the case...then again if it was totally obliterated and has bled thru thats another matter....

Try the stain block.....gloss over damp/bleeding walls is an old wives tale.

 

[Leejames]

(wives tale) is that the same as using oil based undercoat to waterbased ?

 

[Zampa]

(wives tale) is that the same as using oil based undercoat to waterbased ?

I, probably like many decorators have used a bit of oil based unders slightly thinned as a sealer for water stains etc...

don't use the water based variety though, that wont work.

But using oil based gloss.....nah.....its a falacy, same as the idea that bare plaster walls should be primed with pva before painting....thats a builders 'thing'.....not a decorators.