In message , Lobster
writes
I had a kitchen ceiling skim plastered a few weeks ago - it was
previously covered in chip-pan grease which I thought I'd successfully
cleaned away with sugar soap. Yuk. However, the newly skimmed ceiling
is now covered in ever-increasing numbers of dark spots which must be
grease leaching through. Although the plaster seems to be stuck OK, I
have no doubt that if I emulsion the ceiling now, I'll just end up
with the spots coming through the paint.

I think I'm going to have to bite the bullet and paint the whole
ceiling with something oil-based before I emulsion it - sound about
right? Is there any value in using expensive half-litre cans of
'stain-block' paint, or will cheap oil-based undercoat do the job
equally well? Or any easier way of achieving a clean white ceiling :-( ?

Dunno.

I do know that the stainblock paint isn't just the same as undercoat,
for one thing the stuff I used was much smellier.
--
Chris French