How to Clean Paint Brushes Properly So They Last for Years

A decent brush should outlive a dozen jobs, and the thing that kills most of them is a rushed rinse at the end of a long day. Clean a water based brush with warm soapy water within a few minutes of putting it down, work the paint out of the base of the bristles rather than just the tips, then reshape it and hang it to dry. Oil based paint needs white spirit first, then soap and water to strip the solvent residue.

Know which paint you used before you start

Everything about the clean up depends on this. Emulsion, acrylic eggshell and most modern water based satinwoods clean with water. Traditional oil based gloss, undercoat, varnish and anything labelled solvent based needs white spirit or brush cleaner to break the film down first. Water will do nothing at all to oil based paint except spread it around and waste time while the paint hardens.

If you are not sure, check the back of the tin. Almost every can states the cleaning method plainly.

Cleaning a water based brush

1. Scrape the excess off first. Drag both faces of the brush across the rim of the tin. Removing that surplus before water touches it saves minutes of rinsing.
2. Run warm water, not hot. Very hot water can soften the adhesive holding the bristles in the ferrule and encourages some paints to set.
3. Work the paint out from the ferrule downwards. Hold the brush under the tap and squeeze the bristles between your fingers and thumb, starting right at the metal and pushing outwards toward the tips. Paint hides at the base and that is exactly where a rushed clean leaves it.
4. Add a little washing up liquid. Lather it through the bristles, then rinse. Repeat until the foam runs clear rather than tinted.
5. Spin or shake out the water. A sharp flick into a bucket or a few spins between your palms removes most of it.
6. Reshape while wet. Pinch the bristles back into their original chisel or flat profile with your fingers. This one step is the difference between a brush that cuts a crisp line next year and one that does not.

Cleaning an oil based brush

The order matters here. Solvent first, detergent second.

• Pour a small amount of white spirit or proprietary brush cleaner into a jar, just enough to cover the bristles but not the ferrule.
• Work the brush against the bottom and sides of the jar for a minute or so, then squeeze the bristles out against the rim.
• Move to a second jar of clean spirit and repeat. One dirty jar will only ever get the brush so clean, which is why professionals use two.
• Wipe the brush on a rag, then wash it through with warm water and washing up liquid. Skipping this leaves an oily residue that goes gummy and traps dust.
• Rinse, shake out, reshape and hang to dry.

Let the used spirit stand in a sealed jar for a few days. The solids settle out and you can decant the clear spirit off the top and reuse it. Take the sludge to a recycling centre, never down a drain.

Rescuing a brush that has started to harden

If the paint has gone tacky but not solid, a long soak in warm soapy water will often bring a water based brush back. Give it a couple of hours, then work the softened paint out with your fingers or a wire brush comb, always combing from the ferrule towards the tips.

Fully hardened paint is a harder ask. Brush restorer will usually shift it, but expect the bristles to end up coarser than they were, so it is rarely worth it on a cheap synthetic brush.

One thing that catches people out: dried paint in the ferrule is what makes a brush fan out and shed. Even if the tips look clean, a stiff, wedge shaped base means paint is still in there and the brush will never lay off smoothly again.

Drying and storage

Let brushes dry completely before they go away. A damp brush shut in a drawer grows mildew and the ferrule corrodes from the inside. Once dry, slide the brush back into its original card wrapper if you kept it, or wrap it loosely in brown paper or a piece of kitchen roll to hold the shape. Store flat or hanging, never standing on the bristles. Avoid bagging a brush that is not bone dry, as that just traps moisture against the metal.

What actually shortens a brush's life

• Leaving it to sit in a tin or a tray while you take a break, so paint creeps up into the ferrule.
• Rinsing only the tips and calling it done.
• Hot water on a synthetic brush, which can distort the filaments.
• Leaving it soaking overnight resting on its bristles in a jar.
• Never reshaping it, so it slowly loses its edge over a handful of jobs.

Get the routine down to three or four minutes at the end of each session and a mid priced brush will last for years. It also paints better throughout its life, because a clean brush holds and releases paint evenly, which is most of what a good finish comes down to.