Can You Thin Emulsion Paint With Water?

Emulsion is probably the most common paint in the UK and is used for all kinds of different jobs. But say you need to thin it for some reason, can you simply thin emulsion paint with water? Well, let’s find out. I got some emulsion and did some thinning in order to answer this question for you.

Can You Thin Emulsion Paint With Water?

Yes, Emulsion is a water-based paint. And as such, it can be thinned down by mixing water in.

Why thin emulsion?

One of the biggest reasons people thin emulsion is in order to create something called a “Mist Coat”. This is a thin layer of watered-down paint applied to porous surfaces.

It is intended to seal the porous surface and allow you to paint normal emulsion on top.

I did a full article on finding the perfect mist coat ratio, read it here.

2-1 Paint Mixture
2-1 Paint Mixture

Here you can see some watered down emulsion paint. I have simply watered this down to a 2:1 ratio. That means it is two parts of paint to every one part water.

Above you can see a plasterboard wall painted with different ratios of watered down paint.

The top section is watered down 2:1, the middle section is 50:50 and the bottom is 1:4.

This illustrates how the more water you add the thinner the paint gets. You can see this from the coverage, the more water there is in the paint the less it covers.

Second Coat On
Second Coat On

Then you can see above that I have applied a normal coat of emulsion on top of the watered-down emulsion.

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Sam Wood

Wood by name, wood by nature. I am a fully qualified, time-served, award-winning joiner with an NVQ Level 3 in Carpentry and Joinery as well as an HNC in Construction. Beyond my joinery qualifications, I have also earned a degree in building surveying. I believe these qualifications make me perfectly positioned to provide expert advice on many different areas of DIY as well as share all of the tips I have picked up in over a decade working on building sites!

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