How To Clean A Polyurethane Brush — Step By Step

Polyurethane is a composition of urethane and organic units in a polymer. It has many uses but is commonly used as a surface coating.

Polyurethane is a resilient substance great for making materials more durable and resistant to corrosion. It is most popularly used in the building and construction industry.


The use of polyurethane in your home will make materials like your wall paint last longer.

A brush is normally used to apply polyurethane on various surfaces. You might want to clean your brush after using it with polyurethane, but how? Using water alone wont work, so you'll need an alternative.

This is how to clean a polyurethane brush:


The most popular method for cleaning a polyurethane brush is the use of paint thinner (mineral spirits).

Another method that is said to work, but isn't very highly recommended, is the use of Kerosene, although this method won't be covered in the article. You can find out more about it here.

Using Paint Thinner

For this method you will need:

  • a towel
  • paint thinner
  • lukewarm water
  • a plastic bowl
Steps in Cleaning a Polyurethane Brush
  1. First fill the plastic bowl halfway with paint thinner. This is because it's only the bristle or foam section that you need to apply the paint thinner to to get rid of the polyurethane.
  2. Dip the brush into the bowl with the paint thinner. Make sure the whole brush section is covered. You can add some paint thinner if needed.
  3. Leave your brush in the bowl for a 15-20 minute period. This will allow the paint thinner to fully penetrate into the polyurethane.
  4. Remove your brush from the plastic bowl, and then rinse it with lukewarm water. The use of cold water would end up hardening the brush. Using hot water is just as hazardous as it could loosen the glue holding the bristles, making them fall out.

Following the steps listed above will get your polyurethane brush clean in no time, which can then be used to paint other wood surfaces possibly cut with a special cutting. This will enable you to use it next time you need (for example, to paint other wood surfaces possibly cut with a special wood cutting tool) it instead of buying a new one.

To get the most out of the use of polyurethane, you should get premium brushes and re-use them.