You might be wondering how to clean your beautiful bristles after a long day of working with polyurethane. Well, worry no more.
Knowing the importance of cleaning and storing polyurethane brushes well is essential. Proper care and maintenance can make your brushes last longer and produce better results in your finishing. They may be an investment, but they’re worth it if you want to do your best work—and keep working!
Here is how to clean and store polyurethane brushes.
How to clean polyurethane brush
Whether you use water or oil-based polyurethane, the essential part is knowing how to clean your brushes. Let’s look at different ways of removing them.
How to clean oil-based polyurethane
Since oil is naturally and water-resistant and the brushes used in applying it are dirtier than synthetic bristles, it may feel tedious to work on them. However, with a little patience and guidance, your brushes will be clean in no time. Shown below is a list of things you will need.
- A clean piece of cloth
- A well-ventilated workspace
- Plenty of water
- Paint thinner/Mineral spirits
- Face mask
- Dish soap
- A pair of gloves
- Nylon scrub brush
Method 1: Cleaning oil-Based Polyurethane Brushes using paint thinners
- The first step is to fill your cup with water but not to the brim
- Add thinner into the water and mix it carefully
- Put your brush into the cup with the solvent
- Bend the brush forth and back to ensure that all the bristles soak your bristles
- Continue bending the brush into the thinner until you see the formation of bubbles and a color change.
- When the thinner is clear, take the brush out of the cup and place it under warm water.
- Add soap to your brush and slowly rub the bristles against your hand
- Repeat the rubbing process until you are completely clear of soap and residue.
- Rinse your brush one last time with warm water before drying it with a microfiber towel
- Make sure you do this every time you use polyurethane.
Method 2: Cleaning oil-Based Polyurethane Brushes Using Mineral Spirits
- Pour mineral spirits into three cups.
- Dip the brush in the first cup and hold it down until all the bristles are covered
- Bend the brush back and forth for the mineral spirits to get in between the bristles
- Once the color in the first cup turns dark brown, move to the next cup and repeat the process.
- Remove the brush from the cups and rinse it under running water
- Apply dish soap to the brush and scrub it thoroughly, running your fingers in between the bristles
- Rinse and repeat the process until you get a clear lather from the brush.
- Hang the brush in your workshop to dry.
How to Clean Water-Based Polyurethane Brushes
Cleaning brushes used in water-based polyurethane takes only a few minutes, and your brush becomes ready for use.
- Dish soap
- A pair of gloves
- Running Water
Step by step on how you clean the brush,
- Fill all the cups with water
- Dip the brush in the first cup and stir it, bending it back and forth until the water gets in between the bristles and changes its color.
- Move the brush onto the next cup and repeat the process until you reach the final cup.
- After that, rinse the brush with running water and add dish soap.
- Scrub the brush with your hands carefully for about three minutes before rinsing it again with running water
- Hang the brush in your workshop to dry.
How to store polyurethane brush between coats
The final step in maintaining your brushes is knowing how to store them between coats. If you are working on your painting project and you feel like taking a short break, then there is no need to clean the brush all the time. In that case, just leave the brush in the polyurethane. But there is a better way.
- If you’re using water-based polyurethane, store the brush in the refrigerator when you take a break. This will help the bristles stay straight and prevent the brush from drying.
- For oil-based polyurethanes, wrap the brush tightly in a Ziploc sandwich bag and store it at room temperature.
When ready to use the brush again, dip it in mineral spirits to soften the bristles. Remove excess liquid by wiping the brush on a rag or paper towel. Use short strokes to apply finish so as not to overload the bristles with too much finish at once.
How to store polyurethane brush overnight
Suppose you need to store the brush overnight or for a couple of nights. In that case, you can avoid having to clean it if you wrap it tightly in plastic wrap so no air can get in, or scrunch the bristles against the bottom of a jar or can of mineral spirits, then hang it in the container with the mineral spirits covering at least a quarter way up the bristles.
Notice the extra hole I drilled in the brush handle, so the brush hangs with its bristles, not touching the bottom of the jar. If the bristles rest on the bottom, they may become permanently bent.
In the morning, give your brush a quick shake or rinse to remove any residual solvent before using it again.
What is a polyurethane brush?
A polyurethane brush is a type of paintbrush that is designed for use with polyurethane-based products. These brushes are made with synthetic bristles resistant to wear and tear, making them ideal for heavy-duty projects.
Can we use any brush for poly application? What options do we have?
When applying polyurethane, you have a few different brush options. Natural bristle brushes are the best choice for water-based poly, while synthetic brushes can be used for either water- or oil-based poly. Foam brushes are also an option, but they’re not as durable as the other two types.
Tips To Guide You on How To Clean your Polyurethane Brush
- Type of the Brush
The difficulty in cleaning polyurethane brushes lies in the type of brush you are using. Removing polyurethane from natural bristles is more difficult than using a synthetic brush. Since natural hair bristles are longer than synthetic ones, vigorous scrubbing can cause damage to them.
- Be Careful While Working with Solvents
Solvents used in removing polyurethane are made of toxic substances and, therefore, can harm our health. So next time you deal with paint thinner and mineral spirits, ensure you are wearing protective gear and working in a well-ventilated place. It’s also good practice to thoroughly wash your hands after handling solvents and ensure you have a set of nitrile gloves on hand when cleaning brushes with mineral spirit.
Also, check our article on How to Clean Polyurethane the right way | Protect your poly
What type of bristles are used when applying polyurethane?
Depending on the type of polyurethane you are using. Here are different types of brushes you may use.
- Natural bristles
They are used in applying oil-based polyurethane. The brushes are animal hair, making them easy to absorb and spread oil finishes. Natural bristles are quite expensive, so it is important to take good care of them.
- Synthetic Bristles
They are the best for the application of water-based finishes. Synthetic brushes do not pick up a lot of moisture, give a more even coat, and are cheaper than natural brushes.
Types of Polyurethane
All polyurethane foam serves the same purpose, but their strengths and weaknesses may slightly differ. There are two types of polyurethane namely.
- Oil-based polyurethane
The key component in this type of polyurethane is that it has an oil base. The oils can either be natural or synthetic. It is golden brown, and that is what distinguishes it from water-based polyurethane. To add to that, it is more challenging to remove from surfaces because it easily penetrates and bonds with the surface.
- Water-based polyurethane
It is a highly favored type of polyurethane because it is friendly to the environment. Water-based polyurethane takes four to six hours to dry, thus making it easier to clean or remove with a piece of cloth and water.
Frequently asked questions
Can you use a brush comb to clean the polyurethane brush?
Of course, yes. A brush comb is a double-headed wire brush made of brass bristles and stainless steel pins to speed up paint and varnish removal from brush bristles.
The comb is gently put into the brush bristles and stroked downwards repeatedly to remove polyurethane residue. Using a brush comb to clean your brush not only save your time but also ensures your brushes last long.
Why should I clean my polyurethane brushes?
- It saves you time and Money.
Getting abrupt jobs and some pleasant surprises are normal when you are a passionate woodworker. But what happens when you don’t have a brush at hand? Will, you run to the shop to get a new brush or try washing the one you ignored since your last project. The bottom line is that you are always ready.
- It shows you are a professional
When people consider you to be a DIY pro, they expect you to have some tools at hand. Therefore, you should always have a clean and organized workshop.
- Adds life to your polyurethane brush
Sometimes it does not depend on the quality of your brushes but on how you clean them. Cleaning your brushes on time and drying them properly makes them last longer.
- It is good for your health.
Since polyurethane is made of harmful substances, it poses health risks to human bodies. So when using it, remember to keep all your tools clean and the remaining chemicals covered.
Bottom Line: Cleaning and Storing Polyurethane Brushes
Cleaning polyurethane brushes save time and money and protect your life and image. Although the cleaning process may seem tedious, the results are admirable. Shown above are different methods of cleaning and storing polyurethane brushes.