How To Clean Polyurethane Brush
Wring it out before storing it.
How to clean polyurethane brush. Allow the paint thinner to fully penetrate the polyurethane within the brush. Since there are water based polyurethanes that you can clean up with water you can use those. We can use white spirit as well as paint thinner to get rid of the polyurethane. If you want to use an alkyd clean thoroughly not just a dunk with paint thinner takes the paint into solution and flushes it away then with acetone takes the thinner into solution and flushes it away then with water takes the acetone into solution and flushes it away as well as acting as a solvent for the soap.
Keep the brush under the running water until it no longer has any soap bubbles in its bristles. If the brush has dried hard you should soak it in water. However start with a good quality brush. Clean the brush thoroughly.
Oil based polyurethane requires you to use chemicals for cleaning. Massage the bristles until polyurethane becomes soft. Avoid using hot water which can damage the brush. Wring the brush out with a paper towel bending the bristles back and forth to remove as much of the finish and solvent as you can.
Then move the brush to a shallow container and use a wire brush to comb through the bristles loosening the paint deep in the brush from both sides. Step 4 remove the brush from the bowl and rinse it with lukewarm water. If you used oil based polyurethane you want to use paint thinner to remove any residue. Then rub the bristles in hand bar.
Leave the brush in the bowl of paint thinner for 15 to 20 minutes. Rub dish soap into the brush bristles and work it into a lather.