Had one of bedrooms plastered a couple of weeks ago,
All dried out, I mixed up a mist coat comprising of roughly 9 parts Leylands Contract Matt PBW and 1 part water,
Mixed well.
covered and dried well,
I decided to start the first coat of Dulux Diamond PBW, I put this on a diluted 9-1 ration as well as its already a very thick coat and the Leyland is by nature a very chalky finish and I wanted it to adhere, Went on well,
However when I did the masking tape test this morning, It’s pulled patches of the Diamond off, Not lots but certainly enough to make me concerned,
Questions are;

Should I not dilute the Diamond? should I do another coat of leyland mist on the walls before starting diamond?

Its going to be a nursery, hence the diamond paint so durability really is a must….

Any help would be appreciated!

I don’t think you put enough water in your mist coat. I’m not a painter and decorator but I think I used more like 2:1 paint to water, very thin. It needs to soak in rather than form a coat

A couple of weeks isn’t very long to leave plaster to dry unless it was a thin skim. Did you add extra heat to the room? Also, as above, that wasn’t much water in the mist. Should be pretty watery

When I mist cost plaster I put nearly 40% water into the Leyland trade matt. As said above I like to see it soak in.

I don’t think you put enough water in your mist coat. I’m not a painter and decorator but I think I used more like 2:1 paint to water, very thin. It needs to soak in rather than form a coat

I’m only going by recommendations by Leyland and various other painter decorators on the interweb….

I must admit When I first started to put the 1-9 ratio on I thought it was a tad dry, I watered it down a little more, It seemed to “soak” into the plaster and doing the Masking tape test, the Mist coat stays on the wall, its only the diamond paint which is removed.

yep, 9:1 doesn’t seem like enough by quite a long way.

I’ve just checked the the mist coat on the walls and it seems solid, not scratching or peeling at all,
1-9 is thick but as said, I had watered down a little more, It took around ten minutes for the wall to touch dry but could defo see it soaking in….

Surely if the ration wasn’t watery enough, the mist coat would come off as well as the diamond?
How does the mist coat and top coat best ahere to each other?

Sorry, I thought you meant the whole lot was peeling off back to plaster. How long had you let the diamond stuff dry for, it may need longer.

Sorry, I thought you meant the whole lot was peeling off back to plaster. How long had you let the diamond stuff dry for, it may need longer.

Nope just the diamond, Did it around 7pm yesterday, Tried tape test this morning…..

As said Mist coat is pretty solid, However If I put a scraper to it with force, the mist coat will come off,

I suspect the answer of not watery enough is correct….

Moving forward, Sand down and apply another mist coat, more watery than the first?

Definitely not thin enough. You’ll know when it’s thin enough cos you’ll be covered in the stuff 🙂 I also find that tape always pull away new emulsion, it needs to be bone dry.

Let it dry for a week and test again, surely it needs more time to fully cure/set whatever it is that this paint does

when I did the masking tape test this morning

You used masking tape. How long was it on for? Most masking tape is only meant to be on 24hours max otherwise it tends to get stuck to whatever it is on. I tend to use a tape more suitable for painting these days even though it’s more expensive as it seems to cause less problems.

If you only had the tape on for an hour or so then this isn’t the problem 🙁

Masking tape test is literally put some tape on, peel it off after a few seconds,

Fair enough. Tx

Sanding down the current mist coat (What a mess!!!) and I think its maybe not as bad as i initially thought, Yes I can scratch it off in places but much of it isn’t to bad,

Going to sand down where it comes off easily, brush and vacuum the dust way before applying a 50/50 diamond, hoping this adheres a tad better.

I’ve found that with the Leyland paint I’ve had to water down every coat not just the first mist coat. It covers well but it is very chalky and I’ve sanded it very lightly between coats before.

brush and vacuum the dust

give it a once over with a damp cloth to remove any dust

Just had my kitchen plastered I was told 50 /50 for first mist coat then one with a 60/40 paint water.

It covers well but it is very chalky and I’ve sanded it very lightly between coats before.

This, Seems to adhered to the plaster fairly well and I would have done better at a 60/40,
Now sanded down, not to plaster but its ironed out imperfections and made the most amount of mess!

If I wipe down with a damp cloth, I’ll no doubt have to wait another 24hrs for the walls to dry again!

Hell of lesson but it sure beats lining paper!

50/50 for your miscoat I use dulux supermatt but any trade paint designed for new plaster should be fine. You dont say how long you’ve left the paint for though, adding a vinyl based paint straight away won’t let the plaster carry on drying out so leave it for 3/4 weeks first. Adding the diamond paint now will stop the plaster breathing and it won’t adhere properly.

I applied the watered down diamond (which is water based) about 4 hours after completing the mist.
Does a mist coat really require 2-3 weeks to dry before painting the top coats?

Can I apply another coat of diluted contract matt now?

Of all the trades and various jobs, Misting onto plaster seems to have the most varied amount of conflicting information,

Can you talk us through the masking tape test.

Can you talk us through the masking tape test.

Masking tape on the paint, Pull it, if it leaves the paint on, its said that you’ve done things correctly, If it pulls paint off, I guess i’ve either done it incorrectly OR too soon,
If you peel it and you see pink goo, Call the Ghostbusters.
To be honest its something I’ve done to determine if I’m painting correctly,
I suspect a Painter decorator may laugh at me….

tacopowell – Member

If I wipe down with a damp cloth, I’ll no doubt have to wait another 24hrs for the walls to dry again!

Nah. If you are sanding before re-painting I would definitely wipe down with a damp cloth before the next coat. You’ll never get all the fine dust off just by brushing & vacuuming.
But, if you wring out the cloth well, it’ll only take 30 mins or so (probably less) for the wall to dry out – cup of tea after wiping the wall and you’ll be good to go.

I would dilute more. I m not sure if its true of emulsions but for wood the guy at johnstons told me never to mix brands of coats, so i dont now.

Your diamond matt topcoat needs time to cure that’s all. Durable/Scrubbable emulsions are mostly based around acrylic resins and can take up to 30 days in some instances to cure fully before being able to be wiped, cleaned down or attacked with tape for that matter 😉

Your mist coat sounds fine if it hasn’t pulled off with the tape. Just follow the instructions on the back of the tubs of paint and you can’t go far wrong. Dusting and cleaning down the plaster prior to the mistcoat is also best practice to prevent adhesion issues.

Probably too late now but if you’ve lots more to do then I’d suggest forgetting the dulux and using crown clean extreme, little green intelligent emulsion or isomat 2000 scrubs emulsion.

I started this thread on various other forums and reading other similar threads its amazing how much conflicting information there really is on the subject of painting decorating,
I’m almost certain no one actually knows what they’re doing.
The one thing that can truly tell me whats going on is my walls.
Thanks for the help so far, I’ve found it useful if not conflicting!

Your diamond matt topcoat needs time to cure that’s all. Durable/Scrubbable emulsions are mostly based around acrylic resins and can take up to 30 days in some instances to cure fully before being able to be wiped, cleaned down or attacked with tape for that matter

Your mist coat sounds fine if it hasn’t pulled off with the tape. Just follow the instructions on the back of the tubs of paint and you can’t go far wrong. Dusting and cleaning down the plaster prior to the mistcoat is also best practice to prevent adhesion issues.

This gives me confidence that I’m heading in the correct direction, Ta 😉

I suspect a Painter decorator may laugh at me….

Let them laugh safe in the knowledge that they do the most god awful tedious job around the house. Well cutting in and woodwork etc aren’t too bad but if hell exists then it’s an infinite wall with an infinite bucket of emulsion. And in the very inner circle of hell is the infinite ceiling.

The devil is lining paper.

I started this thread on various other forums and reading other similar threads its amazing how much conflicting information there really is on the subject of painting decorating,
I’m almost certain no one actually knows what they’re doing.

Mainly because a lot of the people on the internet giving the information don’t make a living out of doing the work! Decorators will have conflicting views on products and brands etc but at the end of the day there are correct ways of doing things.

All the best with your project anyway 🙂