Mist coat problems

[Suikoden]

Hi guys,

First time poster, long time reader.

I have just had the top floor of my house completely plastered. Fresh plasterboards etc.

I have let the plaster dry and given it a mist coat of Leyland Contract Matt. I was told around 80/20 mix for the mist coat with this paint.

Whilst going around and painting, it did feel thick and was possibly even a little more that 80% paint - the reason I wanted it thicker is because I’d finished off some Dulux Matt first at a 70% mix, on one wall, which looked like it covered better than the Leyland mix.

Anyway, mostly finished and then let dry. I then painted some samples on to see colours (this was F&B but final will be Dulux in the relevant colour mixed).

The samples can easily be peeled off in sheets.

So…with the above info is the problem that it was too dry and so the paint isn’t sticking to the mist coat? Just another thin coat?

Do I need to sand everything back and start again (as it feels very slightly dusty when I rub my hand across the mist coat)?

Any help appreciated.

Thank you!

 

[Suikoden]

As a quick Update:

Yesterday I painted two different matts on the mist coat (little green and earthborn) some testers I had from a different project.

This morning after writing my original post I went and did the masking tape test (the reason I knew about the peeling paint was removal of masking tape when I stuck a colour card to the F&B paint).

Anyway, the little green paint very slightly came away but did not come away under a bit of rubbing like the F&B did.

The earth born stuck fast. No come away at all.

Given all that. Any ideas what I should do to avoid any potential issues.

Many thanks

 

[Wayners]

I prime all my plastering with acrylic primer undercoat. It's nice and smooth to the touch and seals the surface. I add 10- 15% water.
I sometimes buy a tinted primer to see what it's like for colour prior to buying the top coat.
Contract matt although popular, is not a plaster primer. It's a paint that allows a new building to dry out through it for 6 months, then the home owners can emulsion over.
Contract Matt is very chalky and dry, so some emulsions don't flow well or grip well to the surface so applying a primer over is the solution. Another good product to prime plaster or contract emulsion is bullseye 123.

F&B recommend their primer before applying top coats, so they sell what is really just an acrylic primer. If you don't use the recommended primer (or equivalent) you will get problems sometimes.

You also need to let paint cure for a few days to fully harden before testing.
Also take a look at the online application data sheets for the paints you have bought. Everything you want to know will be written on the pdf.

Oh

Some use gardz to prime but it can seal too well. It's good if applying a durable emulsion over though like easycare or diamond matt ect

 

[Suikoden]

To confirm, if I used a Dulux mist coat over the top as a primer. Would that work? Which Dulux product would I need?

I want to use Dulux diamond Matt as the top coat.

Just so you have all the info.

Cheers

 

[Wayners]

Normally you would put primer on plaster then your Dulux colour. I don't use contract paint as a primer though. Maybe add a splash of water to top coats if required depending on the paint.

If F&B is being used i would prime plaster with acrylic primer as it's cheap enough. Then f&b primer followed by top coats .
Although read manufacturers data sheet for specific advice.
This covers the different paint types