Painting plaster

pledgeX

Yesterday I painted the first mist coat on my newly plastered walls. I used some Leyland trade contract matt emulsion. The box said to water it down 9 parts paint to 1 part paint but this still seemed very thick and most people online recommended watering it down further. Is was probably more like 70/30 in the end.

I've come down today and am really surprised by the results, on first glance you'd think I'd finished painting. I was expecting it to be much more patchy. Have I done something wrong?! The plaster was definitely dry. It's been a couple of weeks since it was done (just a skim) and it was a nice uniform pale pink.

Couple of other questions:

1) I was planning to do another mist coat, but since it's looking quite good, I was just going to skip to the paint I want to finish it in. Is this a good idea?

2) It's a kitchen, so a large portion of the walls will be covered in tiles/units. Do I still need to give it a finishing coat for some reason in these areas, or can I just leave it at the mist coast?

3) How long should I wait until painting the top coat? I don't want to start painting again if the plaster is still sucking the moisture out of the mist coat.

bigfreddiel

I've used watered down Unibond to seal a newly plastered wall, but a mist coat is fine as well. fj

theonlywayisup

I am no decorating expert but whenever we've painted new plaster we used a 50/50 emulsion/water mist coat. I would NEVER use unibond or any other type of PVA sealant.

1. You only do one mist coat. Next coat as normal.
2. I would.
3. I would leave 12 hours in this weather.

Mr.Generous

you only need to mist more if its really patchy where it looks ok just start painting. Once the paint is fully dry you can do another coat, if its at all tacky it may well peel off.
I take it the job was a plaster skim, thin coat and not browning / bonding coat followed by a finish? If fully plastered onto bare masonry was the case you will need to just use paint for new plaster or a non vinyl type emulsion to let all the salts and crystals form and settle.
You don't have to do anything else where the units and tiling are going but remember a painted surface is excellent for tile adhesion and probably a good idea behind units anyway.

pledgeX

Mr.Generous wrote: »

I take it the job was a plaster skim, thin coat and not browning / bonding coat followed by a finish? If fully plastered onto bare masonry was the case you will need to just use paint for new plaster or a non vinyl type emulsion to let all the salts and crystals form and settle.

Yes, the area I painted was just a plaster skim. There are other areas that have a bonding coat followed by plaster, but these areas haven't dried yet so I've not done a mist coat on them yet.

Mr.Generous wrote: »

You don't have to do anything else where the units and tiling are going but remember a painted surface is excellent for tile adhesion and probably a good idea behind units anyway.

I understand the reasoning for painting where the tiles will go, but why bother behind the units?

jcb208

Also make sure you thin the top coats 20% as well If you don't want to end up with heavy brush marks and roller stipple

Silver-Surfer_2

bigfreddiel wrote: »

I've used watered down Unibond to seal a newly plastered wall, but a mist coat is fine as well. fj

Don't do this.

bigfreddiel

Silver-Surfer wrote: »

Don't do this.

Why not, is it to do with leaving the plaster breathable. Will it cause condensation or damp problems?

Cheers fj

TheCyclingProgrammer

bigfreddiel wrote: »

Why not, is it to do with leaving the plaster breathable. Will it cause condensation or damp problems?

Cheers fj

Paint will not soak into the plaster (the whole point of mist coating) if you're slapping it over a layer of PVA. It will peel off in sheets.

PVA is for slapping onto old walls before they are skimmed, not over freshly plastered walls.