Painting freshly plastered walls

[Slider]

Hi guys

Currently mid way through our ensuite re-furb and my mind has turned from plumbing to painting. All walls and ceiling have been skimmed and is now fully dry (plastered about 3 weeks ago).

I am thinking of taking the opportunity whilst no shower enclosure / toilet / basin / vanity unit are installed to give the ceiling a lick of paint, also may paint the walls where we are not tiling.

What is the best method for painting fresh plaster? How many coats will be required? Do I need mix some cheap emulsion with PVA (50-50) for the initial base coat?

TIA

[stuart noble]

IME Crown emulsion has always been fine straight from the tin.

[sm_jamieson]

Fresh dry plaster will absorb the liquid from the paint too quickly and the paint will end up either pealing off or dry and dusty. Usual recommendation is a watered down first coat, but you can just paint it with water first to stop the suction. Or seal the plaster first with a "plaster sealer" (expensive). I do not believe PVA is good in this instance - tends to form a skin unless watered down itself. Also PVA might not be compatible with a paint that does not use PVA its makeup. Remember the problem is the suction of dry plaster, similar to the suction of dry bricks sucking moisture from mortar. The implies that the paint needs it's liquid (water ? something else ?) as part of it's drying / setting method. Anyone know about the chemistry of emulsion paint ?

Simon.

[stuart noble]

Only that the water and the solvents shouldn't be absorbed at a different rate to the resin/pigments. It doesn't matter with the smaller particle size emulsions, but they produce stains rather than paints. Thinning emulsions is like adding water to custard. However much you whip it, it's forever separate