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watering down emulsion
Posted: Sat Feb 19, 2011 9:29 pm
by hammy1976
Hey people,
My mate has been p & d for 3 yrs now. He reckons he always waters down the first coat of emulsion. Do you do this as well? What is the reason for doing this other than saving money and making the paint easier and quicker to work with.
opinions would be appreciated
Re: watering down emulsion
Posted: Sat Feb 19, 2011 11:45 pm
by JK Decorator
watering down emulsion so it flows better is common, just makes it easier to use but dont mistake pi$$ing it down for a mis coat, two totally different things
mis coats are usually 60 40 (personally i like a thicker mis coat) this is used to seal BARE plaster, (not PVA) before the colour coats
Re: watering down emulsion
Posted: Sun Feb 20, 2011 8:07 am
by jozeffo
Trade paints are made to be thinned. Porous surfaces benefit from more water thAn less porous do. You cannot thicken paint, so it comes thick and should be thinned to suit. It should improve your cutting in and speed of rolling. It also leaves a smoother surface
Thinning with ten percent water will vastly improve the coverage of the paint, this is convenient because it saves money provided you don't end up applying more coats.
Re: watering down emulsion
Posted: Sun Feb 20, 2011 9:20 am
by feva
i only use dulux trade, i find that i only have to thin down there PBW vinyl matt, its just for too thick for my liking, but i use both water and Flotrol.
i think you find hammy that every one is different, what one person does the other wont, i would just try different ways of doing things, theres a really good post on here about people tips, just try some out and see if they suit your way of working. just use common sense if some one is saying to mix 1/2 liter of white sprite to emulsion then thats the type of thing to ignore lol
Re: watering down emulsion
Posted: Sun Feb 20, 2011 9:26 am
by royaloakcarpentry
I use dulux trade and only thin for mist coating. Other than that subsequent coats or redecs are full strength. never felt the urge to thin it down and not seen any of our decorators thin it either.
Re: watering down emulsion
Posted: Sun Feb 20, 2011 11:06 am
by jozeffo
I should probably make it clear that it is not a requirement to thin paint, but if you thin it for mist coating, why not for other porous surfaces? Even half a pint of water in 5L makes the job easier and I think leaves a better finish.
Re: watering down emulsion
Posted: Sun Feb 20, 2011 11:31 am
by royaloakcarpentry
Jozeffo..............technically, I would still call any coat watered down to form a bond to a porous surface, a mist coat.
Re: watering down emulsion
Posted: Sun Feb 20, 2011 11:39 am
by jozeffo
ROC, I can see what you mean.
I use alot of microporous paint (Leland Superleytex for example) to mist coat and because it allows plaster to dry through it, the next coat needs to be watered down to cope with it. It would confuse anyone who I am working with if I referred to the second coat as a mist coat as well. It isn't watered down nearly as much.
Re: watering down emulsion
Posted: Sun Feb 20, 2011 4:57 pm
by upagumtree
Thinning emulsion is a matter of preference really, I use Macphersons vinyl matt and find a drop of water makes it roll out better and certainly helps when cutting in.
Re: watering down emulsion
Posted: Sun Feb 20, 2011 7:02 pm
by hammy1976
thanks for all your good advice everyone. so just to recap
* mist coat (very watered down) = to seal plastered or porous walls
* 1st coat (10% watered down)
* 2nd coat - not watered down or maybe just enough to make cutting in and spreading easier and quicker
I know everyone does things slightly differently and circumstances may be such that the above following guidelines will change but do you think if i follow the above basic structure i should be okay
comments please
Re: watering down emulsion
Posted: Sun Feb 20, 2011 7:25 pm
by Tom d'Angler
I only water down emulsion if I am doing a mist coat (it is "mist coat", not "mis coat", isn't it?).
I use a non-vinyl emulsion (Glidden contract matt).
On the tin it says add 20% water, so 80/20, not 60/40.
Other than that I always (unless a customer has already bought their own paint) use Dulux Trade Vinyl Matt and never add any water.
It seems to work very well for me. It goes on really well and I've never felt the need to water it down.
I'm not saying it is wrong to do it ... I've just not felt the need myself.
However, when the subject of watering paint comes up, I often wonder what a customer would think if they saw me watering down paint ... I've had a few customers moan about previous decorators and say "I'm sure they watered down their paint", etc. I wouldn't want them to think I was ripping them off. I always tell customers when I am using a mist-coat and why and explain that I add 20% water because it is going on bare plaster.
Re: watering down emulsion
Posted: Sun Feb 20, 2011 7:33 pm
by hammy1976
Hi tom
why do you use a non vinyl for a mist coat??
Re: watering down emulsion
Posted: Sun Feb 20, 2011 7:43 pm
by Beachcomber
Tom d'Angler wrote: ..........(unless a customer has already bought their own paint)..............
Guaranteed way to make your heart sink - the customer saying 'its ok - we've got the paint already'
Re: watering down emulsion
Posted: Sun Feb 20, 2011 8:15 pm
by jozeffo
I always tell he customers to choose the colour and I will pick up the paint because it will cost them more than I will pay and they will get retail paint whereas trade is much better.
The biggest howler I have had is when one of them chose Homebase paint and we needed 80L. They didn't do an eggshell and the satin only came in 750 ml! Luckily, they saw sense and we went with Crown. Crown acrylic eggshell I can recommend as a result.
Re: watering down emulsion
Posted: Sun Feb 20, 2011 10:05 pm
by Puma
Beachcomber wrote:Tom d'Angler wrote: ..........(unless a customer has already bought their own paint)..............
Guaranteed way to make your heart sink - the customer saying 'its ok - we've got the paint already'
TRUE!
It depends slightly on the roller as to whether you thin down, a cheap roller generally won't handle thick paint so well.
Sometimes you can thin a little to SPEED UP rolling and get a better finish if you know you're going to have to do two coats anyway.
Always thin as much as is correct to do so, so you can to make rolling faster.
Watch out for Diamond Matt and soft sheen - the sheen level changes with the amount of thinning - the pigment rises to the surface and dulls the paint with thinned coats. Keep all shiny paint at same thinness.
Some purples and dusky pinks suffer from pigment separation which is worsened with thinned paint and can lead to colour changes.
You can thin Ultra High Opacity Matt and still get great coverage - it's then like 1.5 cans in the one can.