How to Remove Dried Polyurethane from a Paint Brush?

When it comes to tackling home improvement projects, there are few materials as versatile as Polyurethane. This synthetic resin can be used as an adhesive, sealant, or coating and is often used to protect wood floors, furniture, and trim. But while Polyurethane is durable and long-lasting, removing it can be a pain if it gets on your paintbrush.

Luckily, you can get your brush clean and ready for its next project with patience and the proper techniques. To remove dried Polyurethane from a paintbrush, soak the brush in a solution of denatured alcohol and water. This will soften the Polyurethane and make it easier to remove.

Here, I will show you how to remove dried Polyurethane from a paintbrush in simple steps. So stay with us until the end of this article.

How to Remove Dried Polyurethane from a Paint Brush? A step-by-step guide

If you have any dried polyurethane on your paintbrush, don’t worry! With some effort, you can remove it and get your brush back to normal. Just follow the steps below, and your brush will look good as new in no time.

What You Will Need

  • Paper towels
  • A paintbrush
  • Mineral spirits
  • A container

Step 1: Paper towels

To remove Polyurethane from a paintbrush, use paper towels to blot as much of the substance as possible. Gently work the bristles of the brush back and forth against the paper towels until most of the Polyurethane has been removed. If necessary, you can also use paint thinner to remove any remaining residue.

Step 2: Put mineral spirits in a container

When using mineral spirits, always pour the chemical into a container first and then follow the instructions on the can to see how much you will need. It is important to use safety gloves to avoid getting the chemical on your skin.

Step 3: Soak the paintbrush in the mineral spirits

Soak the brush in mineral spirits for at least 15 minutes to properly clean your paintbrush after using Polyurethane. This will help to loosen the dried Polyurethane from the bristles, making it easier to remove.

Step 4: Remove the paintbrush from the mineral spirits

Remove the paintbrush from the mineral spirits and use your fingers to remove any remaining polyurethane from the bristles gently. If necessary, repeat this process several times.

Step 5: Rinse the paintbrush

To properly clean your paintbrush after use, rinse the brush with warm water to remove mineral spirits. Then, use soap and water to remove any remaining residue from the brush’s bristles. This will ensure that your brush is clean and ready for use the next time you need it.

Step 6: Dry the paintbrush

Wipe the paintbrush with a clean, dry cloth to remove any excess paint. Doing this will help extend your brush’s life and ensure it is ready to use again.

How do you store your paint Brushes after Using Polyurethane?

After you finish using Polyurethane, it is essential to store your brushes properly to extend their life and prevent them from becoming ruined. Here are some tips on how to store your brushes after using Polyurethane:

Rinse the Brushes in Mineral Spirits

After you are done using the Polyurethane, it is important to rinse the brushes in mineral spirits. This will help to remove any residual polyurethane from the brushes and prevent it from hardening.

Wrap the Brushes in Aluminum Foil

When rinsing the brushes in mineral spirits, wrap them tightly in aluminum foil. This will help to keep the brushes moist and prevent the Polyurethane from hardening on the bristles.

Store the Brushes in a Ziploc Bag

Once the brushes are wrapped in aluminum foil, store them in a Ziploc bag. This will help keep the brushes from drying out and prevent the Polyurethane from leaking.

Store the Brushes in a Cool, Dry Place

Finally, store the brushes in a cool, dry place. This will help to prevent the Polyurethane from hardening and will also extend the life of the brushes.

Which type of brush is best for removing dried polyurethane from a paint brush?

When it comes to removing dried polyurethane from a paint brush, the debate of foam brush vs bristle brush comes into play. Bristle brushes are best for scraping off dried polyurethane, while foam brushes are better for applying smooth coats. Ultimately, it’s a matter of personal preference and the specific task at hand.

Is It Possible To Clean Dried Polyurethane From A Paint Brush With Vinegar?

It is possible to clean dried Polyurethane with a paintbrush with vinegar. However, it is important to note that this will only work if the Polyurethane is still liquid. If the Polyurethane has already hardened, removing it will be much more difficult.

Start by soaking the brush in vinegar for a few hours. This will help to loosen the dried Polyurethane. Once the brush has been soaked, use a stiff-bristled brush to scrub the brush bristles. This should help to remove the majority of the dried Polyurethane.

After soaking and scrubbing the brush, rinse it off with warm water. You may need to repeat this process before the brush is completely clean. Once the brush is free of dried Polyurethane, wash it with soap and water.

The Proper Way to Clean Polyurethane Paint Brush


When working with Polyurethane, it’s important to be aware that the substance can be very difficult to remove from surfaces if it’s not dealt with quickly. If you accidentally get some on your paintbrush, the best course of action is to immediately soak the brush in a brush cleaner or mineral spirits.

Let the brush soak for a few minutes before using a paper towel to wipe away the Polyurethane. If the substance has already dried, you may need a stiff-bristled brush to scrub away the residue. With some elbow grease, you should be able to remove the Polyurethane without damaging the surface underneath.

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