Thinning emulsion -- how much?

[Alwayshelpful]

Hello

I am very occasional DIY painter so so try not to laugh too much at this.

When I've used emulsion paint before I've had trouble trying to 'ease' out the brush marks -- they stay as kind of tram-lines in the surface so I've thought that perhaps I should have thinned the paint a bit so it would sort of flow and settle better. I know a lot of people would use a roler but my latest job is on some very uneven old cottage plaster and with lots of obstructions so there'd be more edge to cut in with a brush than middle to role anyway. I have been using a decent Harris "Taskmaster" range brush too.

If I should be thinning what sort of consitancy am I looking for. Eg. like water? (probably not) Milk? Thin cream? etc. I know this is very difficult to describe in words but any idea would be helpful.

For information. I will be using Dulux colour mix service matt finish (I alredy have the paint) and the wall is alredy painted with a sound and fairly 'flat' finish of slightly lighter colour than the new. The directions on the tin state not to thin or even stir but it's the same range as I've used before and I'm sure it's too thick out of the tin.

Sorry to ramble on a bit and any help would be much appreciated.

William

[Puma]

If you stir the paint and have a look at how it flows in the can - if it keeps soft peaks it is too thick. However it is impossible to say what is exactly right as walls will suck out the moisture at a different rate so you just have to thin it down until the marks disappear. The main thing is a good brush in good condition. Bristle brushes take a while to soften up a bit. You cannot thin too much, but obviously if it is very thin you won't get much coverage - so it is about getting the balance right. Harris do cheap good quality brushes in my experience.

[Have Brush Will Travel]

Puma is right...and you must also balance the thinning against drying time..the thinner the emulsion the quicker its going to dry..the quicker it dries..the less time the brush marks mave in order to flow out.

Dulux can often come up on the 'dry' side when your applying it...especially by brush...

Instead of thinning it I would add some paint conditioner instead...Owatrol do a very good one..it improves the flow and helps reduce brush marks.

Use a good quality 3 inch synthetic brush too...and do it when the room is cool..the warmer it is the quicker the paint will dry.

[bobbie-dazzler]

Myself personally always thin my paint, I never lose any of the coverage, but I always thin even if its just 5%-10%, I find that the paint goes on smoother, plus of course there are no brush marks, and I get a better finish, that and using a decent roller.

You, as you say in your own words, (an occasional painter) will not be as fast with the cuttin-in and rolling, so therefore thinning the paint, or even using HB suggestion, will make the painting just that bit easier for you.

[darrenc]

Interesting that it says on the tin not to thin or stir. This normally applies to thixotropic paints like non drip gloss. It could be that its a thixotropic emulsion (one coat perhaps)? If so the simple solution is to change the paint your using to trade (which you can thin as BD says) or even pre-mixed off the shelf would be better.

[Alwayshelpful]

Thanks to all replies.

It looks as though my "gut feeling" that I would be better with paint a little thinner than out of the tin is right.

darrenc: I've got the tin here now. A selective quote from the label

"...Do not stair unless colourant has not been fully mixed in ... up t0 10%water may be added ... to ease application if required .... apply 1 or 2 coats ..."

So it looks as though I can thin it a bit without anything desaterus happening.

I will try to remember to post back here when I've done and let people know how I get on -- it might not be for a bit as there's still some filling etc to do and I'm fitting it in arround work.

Thanks again for the tips.

William

[Have Brush Will Travel]

Ah right...its a mix...

They normally come up on the thin side anyway..the bases are thinner to allow the colourants to mix easy when they are shook up.