How to Clean Paint Brush from Oil Base Poly?

How to Clean A Brush with Oil Based Polyurethane?

I’m trying to clean a brush I use for oil-based poly. Is there a way to do this without ruining the bristles? I’ve tried hot water and dish soap, but it didn’t really work very well.

The best way to clean an oil-based polyurethane brush is with mineral spirits. Mineral spirits are available at most hardware stores and are not the same as paint thinner or turpentine, which are made from petroleum distillates and can damage the bristles of your brush.

To Clean your Brush of Polyurethane

If you’re working with oil-based polyurethane, you’ll need to clean your brushes immediately after use. Oil-based polyurethane is highly toxic and will dry onto your brush as it would on a paint roller. If you leave it on the brush, it will make your next project difficult.

Note: You can use the same method to clean the brushes that you use to clean all of your tools.

Here’s how to clean your paintbrushes with mineral spirits:

Step 1: Paint a layer of mineral spirits over the brush bristles. This will help loosen up any dried paint on the brush, making it easier to remove later on. If you don’t have mineral spirits handy, turpentine is another solvent that works well for cleaning paint brushes and won’t damage the bristles.

Step 2: Soak the brush in mineral spirits for 5 minutes, then remove it from the solution and wipe off any excess paint with a paper towel or rag. The mineral spirits will dissolve any remaining paint from the brush so we can easily remove later it on.

Step 3: Rinse the brush thoroughly under running water, squeezing out any excess paint until it’s clear of color. This will ensure all traces of oil-based paint are removed from your brush so it doesn’t ruin other colors when you use it again later on!

>> See also: Can I Use A Nylon Brush for Polyurethane?

How Do you Clean A Polyurethane Brush without Mineral Spirits?

Cleaning a polyurethane brush without mineral spirits is not as easy as it seems. The easiest way is to use a solvent that will not damage the brush, such as mineral spirits or turpentine. Unfortunately, these solvents are flammable and toxic and can leave a residue on the brush if not cleaned well.

The next best option is water with a little dishwashing soap added to it. This will clean your brush, but leave the bristles stiff if you don’t allow them to dry completely before using them again.

Another option is to use warm water and a mild detergent like “Tide PODS Laundry Detergent Soap Pods” or the “Dawn Dish Soap Ultra Dishwashing Liquid“. This should clean your brush well enough for most jobs but may leave some residue on the bristles of your brush if you don’t rinse thoroughly enough after each stroke of your brush across the surface of your project.

Step 1: Get a Clean Cups of Water. You can use any type of cup, but make sure it’s not large enough to do the job.

Step 2: Deep the Brush into the Cup of Water. Put your brush into the first cup of water and swish it around to get rid of any loose poly or dirt. If you have more than one brush, put each one in a separate cup of water and then repeat step 2 for each brush. This will help the water get in-between the brush bristles.

Step 3: Wash the Brush with Soap. Wash your brush with soap and water in the other second cup until we have removed the poly from it. The soap will help break down any oils on your brush so they can be washed away easily. Once you’ve done this step, rinse out your brush thoroughly to remove any excess soap from its bristles.

Step 4: Hang it upright to Dry. After rinsing out all excess soap with clean water, hang up right your brush somewhere where it won’t drip on anything until it’s completely dry (at least 20 minutes or fewer).

>> See also: How to Clean Nylon Gun Brush

How Do you Clean Brushes between Polyurethane Coats?

You can clean your brushes between coats with either water and soap or with mineral spirits. Be sure to clean them out thoroughly, however, or you may end up with a sticky brush that leaves residue on your project.

You can follow the same steps as me above to clean up your brushes between polyurethane coats. This will prevent them from hardening and becoming more difficult to remove later.


I hope the tips above will help you with your next project. If you’ve tried these methods before, let us know how they worked for you as well. And if you have some tips of your own, don’t hesitate to share them in the comments section below!

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