Why Does Acrylic Paint Get Chunky?

There’s nothing worse than getting all of your supplies ready to start a painting project only to realize that your acrylic paint has become chunky. It doesn’t matter how much of a crafter you are—anyone can fall victim to it.

There are a few things that can cause your smooth paint to become lumpy. Luckily, there’s also a way to fix it.

Acrylic paint becomes chunky when it’s been exposed to too much air. The chunks are actually sections of the paint that have started to dry. The easiest way to fix chunky paint is to remove the chunks and rehydrate the paint if necessary. After that, ensure that your paint stays sealed.

This article will explain the main reasons acrylic paint can get chunky in great detail and what you can do to fix this problem and prevent it from happening in the future: Why Does Acrylic Paint Get Chunky?

Table of Contents

1 What Causes Chunky Paint?
2 How To Fix Chunky Paint
- 2.1 Remove the Chunks
- 2.2 Rehydrate Your Paint
3 How To Prevent Your Paint From Getting Chunky
4 Final Words
5 Sources

What Causes Chunky Paint?

Chunky paint is can be caused by several things:

If the paint is old and has been exposed to air.
If the water in your paint has evaporated.
If the paint has undergone extreme temperature changes.

Exposure To Air Can Cause Chunkyness

The most common cause of chunky paint is simply air exposure. It doesn’t matter if you’ve had your paint for a day, a week, or a year. If your paint is exposed to too much air, it will start to dry out, slowly developing chunks.

The most common way for paint to dry out and become lumpy is not properly closing the can or tube your color comes in. This could merely be due to forgetting to close the container, or it could be due to repeatedly keeping it open for extended periods of time while painting.

Old Paint Can Get Chunky

Paint can develop chunks if it’s too old. While paint doesn’t have an expiration date, it’s typically accepted that acrylic paint has a 5-10 years shelf life once it’s been opened if stored properly.

After this time, the preservative chemicals in the paint will start to break down. That includes preservatives that keep your paint smooth.

Evaporation

Acrylic paint is water-based, which means that it contains water in its mixture. Although this means it will dry faster than oil paint, that does not mean you can varnish it straight away. Though you don’t see the water itself just by looking at the paint, it’s still there and can evaporate.

When the water evaporates inside a sealed container, it will quickly become reabsorbed by the paint. However, evaporated water will escape if the paint container is left open.

Water is one of the main components that keep acrylic paint liquid. If the amount of water in the paint decreases, it will dry out, causing clumps of dried paint to form.

Extreme Temperature Changes Can Also Get Chunkiness in Your Paint!

Extreme temperature changes will also cause acrylic paint to become chunky. If a can or tube of paint was in freezing temperatures and then put in extreme heat and humidity, its composition could go through too many changes and lose its smooth texture.

It’s the same scientific concept that’s at play when ice cream is partially melted and then refrozen—its texture won’t be the same.

While this is a less common cause of chunky paint. Still, if you live in a climate that has strong changes in temperature throughout the year and you keep your color in a location that isn’t climate-controlled, your acrylics may be at risk of changing consistency.

How To Fix Chunky Paint

You might think that once your paint has become chunky, there’s nothing left you can do to salvage it.

That’s not the case. There are some situations when you might not be able to fix your paint, but before you throw it out, it’s worth trying one of these possible solutions first.

Remove the Chunks

The easiest way to fix chunky paint is to remove the lumps. This is the best solution if your paint is mostly smooth and has only a few clumpy or stringy parts.

To do this, you can use a paint strainer, which works in a similar way to a pasta strainer. You’ll just pour your paint through the strainer to catch the clumps.

However, an even easier way to remove the chunks from your paint is to use a small sieve or a paint-stirrer stick. Just stir your paint and carefully remove all the clumps that you find.

Since you’ll be stirring your paint during this process, it will also help your paint recombine—the clumps have caused any parts of your acrylic to separate.

Rehydrate Your Paint

This solution is ideal if there are many clumps and the paint itself is has dried enough to become less liquid. Since acrylic paint is water-based, all you have to do is rehydrate your paint to try to reverse the clumping problem.

Simply stir in a little bit of water at a time. If evaporation or too much air exposure is the reason why your paint is no longer smooth, adding water should help bring it back to its original consistency.

If you decide to try this method, make sure you use a small amount of water at a time to make sure your color doesn’t become too watery.

How To Prevent Your Paint From Getting Chunky

Though clumpy acrylic paint is a common problem, there are steps you can take to keep it from happening to you. By preventing clumps from forming in your paint, you’ll be able to make sure none of your paint goes to waste.

Make sure your paint container is properly sealed when not in use.
Don’t leave your paint open unless you’re actively dipping your brush or pouring it onto your painter’s palette.
Keep track of how long your paint has been open so you can use it before it gets too old.
Keep your paint in a cool place that will maintain a consistent temperature throughout the year.

Final Words

Chunky acrylic paint might seem unusable. However, while it might be easiest to just throw your paint out once it’s become lumpy, you can probably fix it in most scenarios.

Even though it might take some patience, there are things you can do to bring your paint back to its original consistency. It’s also important to know what caused the lumps so you can prevent them in the future.

Sources

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