Painting skimmed plasterboard

[Gary]

I'm in the process of having a conservatory built and it's at the state where all the glazing is in, first fix of electrics and the plaster boards put up and skimmed. The plasterer guy reckoned it could be painted 'by the weekend', which was the weekend just gone, and he said that on the Tuesday when he did the work.

Now here we are 3 days beyond that and the skim has dried to a light brown even finish all over, apart from where I suspect the adhesive is where the boards are glued to the blockwork. These spots are still darker, I guess about 6 inches in diameter each and occur in dots of four, like the spots on the four dice face. The even colour arrived within a few days but these darker spots have been there since about saturday. They seem to grow and shrink in size with the time of day as well, if that makes any sense.

Is this okay to paint at this stage? I'm going to put some Dulux 'paint for new plaster' on first, then some hard wearing emulsion on top.

How long do I leave between the two coats of paint, assuming I can even do that yet. I'd like to get it all painted before the second fix of electrics if I can.

Cheers

Gary

[mark.hannah]

To be honest, I would waint until all dark/damp patches have dried fully - you risk the paint not adhering properly and flaking off.

I used watered down emulsion for the first 2 coats of mine - and it was dry to the touch minutes after it hit the wall - so I would say you could get away with ~2 hours between coats - new plaster is very thirsty!

Mark.

[Andrew Gabriel]

That's expected. Moisture is slowly coming though from the glue, but when it's warmer/drier, it may dry from the surface faster.

I'd echo that - leave it a few days _after_ it all looks dry. Start with watered down matt emulsion, even if the final paint finish will be something different. If switching to a different paint between coats, wait much longer than just dry to touch.

[Slider]

I'd echo that as well. I used 2 or 3 coats of watered down cheap emulsion as first coat, then hit it with some decent stuff. Perfect finish.

[Andrew Gabriel]

It's not obvious to me why you want more than 1 thinned coat, but I doubt it's going to do any harm.

For the first thinned coat, it wants to be more thinned the more polished the plaster finish is.

[Slider]

Each subsequent 'mist' coat watered down less each time. Final coat was good quality full strength emulsion.

[Gary]

On Wed, 8 Oct 2008 14:22:11 +0100, Slider wrote (in article ):

Thank you for all the replies. The dark spots were not apparent yesterday or today so tomorrow SWMBO is going to start painting whilst I'm at work...

I anticipate a good job :-)