Can you use water to clean acrylic paint?

Acrylic paints are water-based and harden when the water evaporates, drying them quickly, so it is essential to thoroughly screw caps onto tubes and bottles after each use.

Cleaning and maintaining your acrylic materials

Acrylic paints are not messy and clean up easily with soap and water. But, like any other technique, you need to take good care of your materials so they last a long time!

Paintbrushes

Because acrylic paints dry fast, you need to make sure your paintbrushes stay wet while… otherwise the paint will cake up the brush, especially around the ferrule, stick the bristles together, and make cleaning up much harder! The best approach is to store those paintbrushes you use the least lying down in a shallow container (a tray or a pie pan).

If you don’t use them for a long time, store them lying down in a box or drawer, away from dust, with a few added mothballs!

5 steps to a clean paintbrush:

• Start by rinsing the bristles of your paintbrush in a container of clean water.
• Next, remove the extra water from the brush bristles, snapping your wrist to shake it hard.
• If you still notice caked paint in the bristles or around the ferrule, gently soap the bristles in the palm of your hand and rinse thoroughly under hot water.
• Gently smooth the bristles between your thumb and index finger to get all the bristles back in place.
• Dry your paintbrush lying flat, on absorbent paper or a hand towel. Once dry, store in a paintbrush container with the bristle end up.

Don’t forget: don’t dry your paintbrushes upright, because water will seep into the ferrule. As a result, the moisture will swell the wood handle and spread the bristles. Your paintbrush will lose its shape and your stroke its fineness!

Getting it right

Do you have dried, caked paint? Try one of these two methods!

• Let your paintbrush soak in hot water: it will soften the paint so you can pull it carefully with your fingers.
• Use a white, spirit type of solvent, then rinse thoroughly.

Do I have to use an Acrylic Brush Cleaner?

Some artists will clean their brushes and other painting tools with the first soap they come across. In most cases this ends up being everyday dish soap or hand soap. While these soaps clean brushes to come degree, they won’t leave your brushes in as good or clean condition as a dedicated brush cleaner. To extend the working life of your brushes as long as possible, we would always recommend using brush cleaner. Artists’ brush cleaners include nourishing oils and moisturisers that regular soaps don’t. The effect of regular soap can be drying, especially on natural hair brushes. Art soaps will not only clean your brushes thoroughly, but will also care for your brushes while doing so.

What are Artists Brush Cleaners and Soaps?

Artists brush cleaners and soaps are available in liquid or solid forms. Unlike household soaps, artist soap both cleans and cares for your painting tools without drying them out. The moisturisers and oils they contain will nourish your brushes and keep their hair in the best condition for longer. The objective for cleaning your brushes should be to get them as close to the condition that you originally bought them. Artist soap is the best product to do that.

We stock a broad range of soaps and cleaners in the Brush Cleaning section of our website. Both solid soaps and liquid cleaners are available to suit all your brush cleaning needs. Our range includes:

1. Loxley Brush Cleaner and Preserver – A solid soap contained in a shallow plastic tub. Wet brushes can be swirled into the soap and rinsed with water. It can also help restore the condition of hardened brushes.
2. The Masters Brush Cleaner and Preserver – A deep cleaning and conditioning soap contained in a plastic tub. Like the Loxley soap, you use it by swirling a wet brush into it. It is a very popular cleaner that is fantastic at restoring your brushes to their original condition.
3. Zest It Acrylic Brush Cleaner and Reviver – This is a solvent-based liquid cleaner. It is popular with artists who are looking for a strong cleaner to remove stubborn, caked on paint.
4. Winsor & Newton Brush Cleaner – This is also solvent-based. Similarly to Zest It, it can be used to loosen dried on acrylic paint.
5. Escoda Brush and Hand Soap – is a mild, nourishing soap block that provides gentle cleaning for both hands and brushes. While it won’t remove dried acrylic paint, it is great for removing wet paint and nourishing your brushes – especially natural hair.

Other Brush Cleaning Accessories

While you can get your brushes perfectly clean with artists’ soaps, we stock a range of brush cleaning accessories that can make your brush cleaning more efficient.

1. Jakar Brush Tub with Palette Lid and Artists Brush Tub – These tubs are great for storing brushes, but also include wells for cleaning. Each well has ridges and raised areas that you can use to work paint residue out of your brush. One of the sections also has an angled wall that can be used to soak brushes.
2. Aluminium Brush Washer – This accessory is essentially a well with a spiral handle that you use to suspend your brushes so they can soak or drip dry. In the well base there is a removable mesh that aids cleaning and also allows paint sediment to settle.
3. Brush pots including the Faber-Castell Clic & Go Water Pot, Lantern Water Pot and Non-Spill Paint Pot. These paint pots are great for taking to classes or painting trips if you don’t want to carry around glass jars. The Trio Water Pot is particularly popular as it allows you to keep three lots of water – so there will surely be some clean water for your final rinse!

• Rinse Well (not pictured)- The Masterson’s Rinse Well is a great brush cleaning accessory, especially if your studio doesn’t have a sink. It offers more stability than moving around multiple jars of water, and allows you to flush out the cleaning well with fresh water as you clean. Just the press of a button will drain water into the waste tank and flush fresh water in from the reservoir bottle. The well also includes moulded ridges to aid cleaning.

What to do with all this sludgy painting water?

I decided that if I was going to continue to use acrylics, I would need to find a solution to cleaning used painting water. Not only that, but I needed to do this with, as far as possible, using what I already had. If we look at the problem from the start, keeping the water clean for longer is a good starting point. Rather than using paper, I use some old sheets which can be reused for a long time. Once they can’t be used any longer, they can be turned into the covers for sketchbooks.

The first thing I tried was filtering the water through a coffee filter – the water was still opaque and sludgy, and very quickly, the coffee filter had clogged up so the process slowed to an unworkable pace. Two coffee filters or a coffee filter with a blue paper inner layer didn’t make much of a difference so it seemed clear that I needed to do something else.

Then, could get the water to evaporate, leaving the sludge behind in the bottom of the bucket? I found four buckets and split the water equally to get the maximum surface area. Sadly, northern hemisphere temperatures in spring are just not high enough to evaporate the water fast enough. I put them in the garden in the sunshine, but progress was just too slow. Warmer weather could make a difference, or pouring the water into a gravel bed. However, I would rather find a solution that requires less permanent space to be allocated, and that has reliable results.

My preferred option for cleaning used acrylic painting water

Finally, I decided to use a version of the method used by Golden. My husband has experience in pharmaceutical manufacturing so we read the process and did some research on what we would need and how we could do it. The principle is simple. This is just a matter of making the solid particles in the water stick together so they can be taken out of the suspension more easily. I had to convert the quantities for a UK context.

The two chemicals involved in this process are commonly used in the garden. Contrary to the concerns expressed on social media, this means they are safe to use with reasonable precautions as you would in the garden, and they are readily available. (Just don’t ingest them and pay attention to any manufacturer’s warnings on the product labels):

• Aluminium Sulphate is commonly referred to as Alum and is used to lower the pH of the soil for acid-loving plants.
• Garden Lime is used as a soil conditioner. It adds calcium and magnesium to the soil and counters acidity.

The effect of using these two substances in the right quantities is that the clear water that is disposed of will be pH neutral.

Step by step process for cleaning used acrylic painting water:

1. Collect the water into a 5 litre bucket
2. Dissolve 15g of Alum in a small container with some of the water. It may not go into a perfect solution but you can get it evenly distributed.
3. Pour this mixture into the sludgy water and mix well with a stick.
4. Sprinkle 15g Lime into the water and mix.
5. Within a few minutes, you should start seeing distinct particles appearing in the water and then settling towards the bottom of the bucket. Once the top layer of the water becomes clearer, measure the pH with a pH meter or paper. If it is above 7, add more lime. If it is below 7, add more Alum.
6. When the Ph measures 7, the water is neutral and the clear water can be carefully poured off and filtered.
7. I used 2 coffee filters are suggested and as you can see from the photographs, the water was completely clear. The water ran through the filters very quickly. I may try re-using the outer coffee filter on my next round with a second clean filter as it came out unclogged with particles. I will update this post with a result when I do.
8. There was a substantial pile of solid paint material left behind. This was the most successful method for cleaning used painting water. From what I have read, it is fine to discard this solid material in your usual way. However, the best way would be to take it to your local council waste centre where they take used household paint for disposal. I plan to collect it in one of my 5 litre buckets with a lid and take it to the council when the volume warrants a trip.

• You can use approximations for the Alum and the Lime – roughly 3tsp would work for 5 litre of water. I used an old spoon measure which is now part of my water cleaning kit.
• I try to reduce the use of consumables so I used an electronic pH meter rather than the papers. It was not expensive and is proving useful in the garden.
• The best way to reduce the impact on the environment is to re-use as much as possible so you’re not always buying more:
  • Buckets – Bird feed comes in 5l plastic buckets. I re-use these for water in the studio and now for cleaning used painting water.
  • Funnel – if you get soft drinks in 2l plastic bottles, you can cut the bottle about 1/3 of the way down. The top can be turned upside down and used as a funnel. The bottom is a good size for receiving the filtered water

  Things I bought:

  Now that I have a safe and effective method of cleaning used painting water I feel much better about using acrylic paint. If you have a different, and equally effective method of cleaning used acrylic painting water before disposal, please let me know. I would love to add it to this post.