new plaster / mist or not or what?

Yeh I know its been asked a million times but im confused.

I've a fair old amount of new plaster to paint. Ive spoken to a few decorators and I'm getting a lot of mixed messages. Some say mist, some say just use Johnstones trade matt emulsion paint as a base, some say just paint it. Some say avoid anything with 'silk' in it because its plastic based. Its confusing.

Ive read a few posts on here and mist coat seems to be the norm with a 5:1 mix.

Ive done a couple of test spots, and my diluted coat seems the worst, it scratches off easily.

What should I be doing really and what's the best advice. Thanks.

mordzy said:

Ive done a couple of test spots, and my diluted coat seems the worst, it scratches off easily.

Click to expand...

the mist coat is not intended to lie on the surface as a durable layer of paint. It is intended to soak into the plaster and kill the suction and form a good base for later coats to adhere.

Mist coats can sometimes practically disappear because they soak in so well. That's good. It's what they are supposed to do. Apply another mist coat. You will know when you have misted enough to kill the suction, because the wall no longer sucks the moisture out of your brush.

if the plaster is new, and still drying out, a non-vinyl paint such as Supermatt is porous and will allow the moisture to escape. They are not very durable, because that's not what they're for, but will make the house look decent while it finishes drying. You can paint over it with a more durable vinyl paint at some convenient time.

if the plaster is already fully dry, you can mist with anything you want, but matt white is cheaper than colours.

The reason for using a matt for your initial coats is that you can overpaint it in future with matt or with silk, according to your desires.

Putting matt over silk, it does not adhere so well because of the shiny surface, so you will get better adhesion by flatting it down, which is extra work.

You can put silk over silk. Silk is easier to clean and does not hold dirt.

Don't put glue on any surface you hope one day to paint.

cheapest white matt you can find , literally.
water it down 70 water 30 paint.
2 coats.
or spend money on screwfix no nonsense bare plaster sealer, which is very good, but dear.

Brill, thanks for the tip. Mist, figuratively speaking is just a term, not that generally its sprayed on in a fine mist and it can should be rolled on? I found that rolling it runs down the walls and makes a right mess.

Its probably just my amateur technique?

Brush.

Sometimes new plaster surface can be too polished to take in any mist coat. I had that problem and eventually had to use Gardz to spot seal the area that doesn't take any paints.