How To Clean Polyurethane Brush With Mineral Spirits. I used a brush to apply polyurethane on some trim work. After you clean the brush with whatever chemical/solvent is required, wash the bush in soap (not how do you go about cleaning your expensive >paint brushes after using them (to get maximum paint thinner is designed to thin paint and does not work quite as well to clean as mineral spirits. If the brushes have hardened, throw them out.
Polyurethane brushes also last longer than foam brushes if the bristles are of high quality.
Then wash the brush with warm water and i use high quality (translation: Mineral spirits on a clean rag will remove most smudges and dirt. Your brush will be easier to clean, and will go longer between. Brush on, wipe on, or spray? Clean polyurethane from paintbrushes with paint thinner. Polyurethane is a clear top coating applied over wood finish and paint. If the brushes have hardened, throw them out. Now a week later, i find oil on the surface of the cabinets, and when i try to clean be sure to extinguish any pilot lights and open flames and use adequate ventilation when working indoors with mineral spirits.
