Painting mist coat problems

Business Man

Business Man

Business Man

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So after having my living room re-plastered I have started giving the walls a mist coat with Leyland contract matt emulsion. I used 10l paint to 1l water

I have come across two problems which I hope someone can help me with.

I have come across patches where the paint will not soak in as much, if i try painting over the patch again with a brush or roller it just drags it

The other problem is around the window reveals where the corners have angle beads, I give the angle beads a coat of zinsser 123 water based paint before the mist coat, this is to prevent any rust stains ruining the wall. However in between the mist coat where the two paints meet up you can see it looks rough.

I did try and sand it down with 120 grade sand paper between mist coats but it's not done much after applying the 2nd coat

I've included picture

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What is a mist coat and why do you need to do it on freshly plastered walls? Just asking as I've had a ceiling replastered and was just going to paint over it with Crown white emulsion.
 
panthro said:
What is a mist coat and why do you need to do it on freshly plastered walls? Just asking as I've had a ceiling replastered and was just going to paint over it with Crown white emulsion.
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Newly plastered walls have high suction. Put standard paint on it and all the moisture will be absorbed causing flaky and cracked paint.

A mist coat is a watered down paint used to cover the wall as a base coat, with the extra moisture so not to cause cracking.
 
Solus said:
Newly plastered walls have high suction. Put standard paint on it and all the moisture will be absorbed causing flaky and cracked paint.

A mist coat is a watered down paint used to cover the wall as a base coat, with the extra moisture so not to cause cracking.
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Great thanks, lucky I found out before painting :)
 
Did the spread get PVA on the finished plaster surface?

Sometimes happens with patch jobs. Plays havok when painting mist coats.

If not, I'd be checking the residual moisture levels. I had an area of damp wall once that paint just sat wet on.

FYI; 10:1 seems strong for a mist. Is that what the instructions suggest?
 
Skiddley yeah thats what it says on the tub ratio 10/1

When I read people dilute to 50/50 it must be water they put on the wall and get everywhere before it reaches the wall :D

I did notice some dark brown drip marks on the plaster near some patch work, got me thinking now if it's pva as the paint can just be wiped off with a damp flannel, how did you deal with it Skiddley?

I have given it another sand down with 120 grade paper and hopefully that works

As for the beads I have decided to go at it again and sand it down

What ever happened to pitchfork? I seem to remember this was his line of work
 
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I used a 1:1 ratio... with the same paint on a re-plastered ceiling not too long ago.

I found the Leyland Contract Matt was slightly thicker than most emulsion I've used before.
 
Business Man said:
Skiddley yeah thats what it says on the tub ratio 10/1

When I read people dilute to 50/50 it must be water they put on the wall and get everywhere before it reaches the wall :D

I did notice some dark brown drip marks on the plaster near some patch work, got me thinking now if it's pva as the paint can just be wiped off with a damp flannel, how did you deal with it Skiddley?
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Yea sanded mine too. Spent more friggin time getting the PVA off, than painting I reckon. Never even occurred to me to use a cloth for the PVA!

I use Dulux supermatt trade, think that's 1/4 water for finish coats and 1/3 water for mist (sprayed) hence the comment. Never used Leyland.
 
Just noticed it says to dilute 9/1 ratio with the tub being 10 liters

I think I should have put more water in it now ffs

I did two coats of this as well

Will this cause any issues do you think?
 
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Kaka said:
I used a 1:1 ratio... with the same paint on a re-plastered ceiling not too long ago.

I found the Leyland Contract Matt was slightly thicker than most emulsion I've used before.
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I'm with this. I've used Dulux Supermatt and gone 50/50 with water. It takes quite a lot of stirring though to get it mixed in. I did 3 coats of each wall in quick succession and the finish seems really good.
 
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The skim coat of plaster has probably been doped, this is when the plasterer has added cement to the skin coat to make it go off quicker. Sanding it down is an option, albeit a messy and time consuming one. Regarding the angle beads, id have used an oil based metal primer on theese. Though tbh, I rarely see the metal ones over here now as most plasterers I know use the plastic ones.
 
Not sure on the best course of action now, I don't know whether to leave it or sand the whole lot down now.

Even at a 9/1 ratio with a 10l tub is 20%, I only did 10% doh

What is the quickest method to strip the pain without damaging the plaster?
 
Sanding down with a sanding block will get the best results. I decorate a lot of new build houses and have seen this problem a few times. An old workmate calls it map of the world effect due to how it looks like the surface is contoured. It is possible though to make it right with a bit of work. 120 grade sandpaper should be plenty. Also make sure to thoroughly dust the walls down once finished. This will ensure better adhesion for subsequent coats of paint.
 
Our whole house was painted in Leyland trade 50:50 water mix two coats on the fresh plaster, yes it's runny and yes it's messy but it Willie you the best finish bar non. Since doing this house I have purchased a room spray so when I come to doing my next fresh plastered room it will be less messy with a cleaner finish.
 
setter said:
The skim coat of plaster has probably been doped, this is when the plasterer has added cement to the skin coat to make it go off quicker. Sanding it down is an option, albeit a messy and time consuming one. Regarding the angle beads, id have used an oil based metal primer on theese. Though tbh, I rarely see the metal ones over here now as most plasterers I know use the plastic ones.
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I've just painted all the metal ones in our house as I've done the walls so they had an emulsion mist followed by two coats of emulsion and even those that have been in ten years+ haven't rusted and shown through they are galvanised so should stay hidden forever.
 
Thanks guys

I'm getting someone in to strip the lot with a mirka dust free sander as it's all the walls plus ceiling, it would take me ages to do and the mess would be horrible. The guy I spoke to says it should be done in a day and be ready to re-mist again.
 
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