If you have remodeled or restored your furniture with polyurethane, then the next thing on your agenda should be tidying up. Learn about how to clean polyurethane from your brushes and admire your handy work.

Polyurethane is a common protective coating used on wooden furniture or items. It is a plastic resin that can be oil or water-based. Polyurethane protects against heat, damage, and water damage while giving a glossy finish. So, it is highly likely that you pick this product for your building projects.

Once you’re done coating with polyurethane, there is the small issue of cleaning your brushes. You don’t want to let the polyurethane set in and ruin your handy brush. Just as you have preserved the longevity of your furniture by applying polyurethane, you must also preserve your brush’s quality. You can take care of your polyurethane brush by cleaning it as soon as possible.

You can’t just start scrubbing away at your brush. Doing so will ruin its longevity. When you are tough on your brushes when cleaning, you will likely pull out some of their bristles. The bristles are simply attached to the base with glue so you must clean a brush with gentleness. This will ensure the quality of your brush and you won’t have to replace I too soon.

Types of Polyurethane

Before learning about how to clean polyurethane brushes, you must identify which kind of polyurethane you have used.


While oil-based polyurethane is more durable and provides greater thermal protection, it is also more toxic and foul-smelling. However, it does give a rich color to your wooden objects.


Water-base polyurethane is more popular because of its low toxicity and odor. It also does not give the wood any color, instead preserves the natural tones.

Knowing which type you have used will determine the cleaning method you need to use.

How to clean oil-based polyurethane brush

To make sure your brush is not damaged during the cleaning process, you will have to follow the steps listed below. But, before you start, make sure you follow health and safety guidelines. These include wearing gloves and goggles and working in a ventilated space. Now, for cleaning oil-based polyurethane from your brush, you must do the following,

Using Mineral Salts

  • Take a paper towel or spare cloth and dampen it with mineral spirits. Use this to dissolve some of the polyurethane.
  • Place your brush in a glass or plastic container and fill it with mineral spirits up to a certain level. Make sure that only the polyurethane-covered bristles are in the mineral spirits while the metal base of the brush is not.
  • Swirl the brush around in the container to ensure the solvent reaches the maximum number of bristles.
  • Let the brush soak for the night.
  • Transfer the now dirty mineral spirits into another container to be disposed of in a hazardous recycling plant. Do not just throw this hazardous material out.
  • Repeat the above-mentioned steps as many times as required until the brush is completely cleaned.
  • Create a mixture of dish soap and hot water to clean out the residual mineral spirits and polyurethane. Again, do not throw this mixture down the drain, dispose of it properly.
  • Gently dry the brush using fresh paper towels or a spare towel.

Using Paint Thinner

You can take the same steps mentioned in the previous method. All you have to do is replace mineral spirits with paint thinner. You can also use acetone in the same manner. In both cases, you must make sure that you follow safety protocols and dispose of the waste properly.

How to clean water-based polyurethane brush

Unlike oil-based, this requires little effort and is a much simpler process. Additionally, you won’t be handling any hazardous materials like mineral spirits or paint thinner for this method. All you need is a bowl of water. Follow these steps to easily remove polyurethane from your brush without paint thinner,

Using Water

  • Fill a bowl with water and let your polyurethane brush soak.
  • As before, only soak the bristles and not the metal base.
  • Do not let it soak overnight, as this reduces the life of your brush. Instead, soak it periodically for 20 minutes.
  • After soaking for 20 minutes, switch out the now dirty water with a clean bowl and let it soak for another 20 minutes.
  • Repeat this process until the brush is completely clean.
  • Remove any residual polyurethane over the sink using your hand or a brush comb. Do so gently.
  • Dry your brush with a paper towel.

How to store polyurethane brush between coats

To take better care of your brushes and increase their life, you must know about the proper storage of your polyurethane brush in between coats. We don’t expect you to finish your project in one go. You are going to have to put the brush down at one point and call it a day. To prevent going through a long cleaning process, you can simply store the brush properly. Since polyurethane dries upon contact with air, there are two things you can do,

  • Let the brush soak in water until the next coat. However, don’t leave it in water overnight as this damages the bristles
  • Wrap the brush tightly in a plastic bag or cling film. Doing this will keep the air out and keep your brush ready for use the next day.


There is nothing more rewarding than a job well done. Working with polyurethane on construction or remodeling projects is common. It is important to take care of the tools you use including your brushes. Your polyurethane brushes must be cleaned properly for the job to be completely over. We hope that this informative article on how to clean polyurethane brushes will prove to be helpful for your post-project cleanup. As mentioned in the article, make sure to follow safety instructions when handling cleaning chemicals.

Share your tips and experience with cleaning polyurethane brushes in the comments below!