For my serial experiments with polymer clay, I often use water based polyurethane as varnish for paint and pigments. It is a liquid substance that I apply with a brush. Quite often I get carried away with my creations, and forget to clean the brush right away. The next day, I usually find a stick instead of a brush, a dried up polyurethane covered used-to-be brush. Because of this, I thought of using lower quality brushes when I work with varnish, but I would have to watch out for loose and stray hairs. So here’s how I tried to rejuvenate polyurethane covered brush.
I tried soaking the ruined brush in water for a few days, but it presents a problem in itself. First of all, one can’t just soak a brush vertically as it would permanently bend. Therefore, I placed a half-full glass jar horizontally, and let the excess water drain. Then, I placed the brush in, and made sure to add more water in the mornings and evenings in case it dried out. Even though polyurethane is water based, water does not dissolve it very well once it’s dry. This soaking method alone produces a somewhat workable brush, but does not return it to the initial state.
Recently, I came across “The Masters” brush cleaner and preserver by B&J, but used it only to get the paint off my brushes. It did a very good job, even on old bushes. The majority of the dry paint was gone, and the brushes became much softer. I always use it to clean brushes now; I expect they will serve me twice as long. Then, I thought I’d give it a try with my dried up polyurethane covered brushes. This brush cleaner did an excellent job at getting off the majority of polyurethane on the first try! I repeated the process a couple of times with hot water, and the brush looks like new now.
Every now and then, I see artists struggling with similar polyurethane related problem, so I hope this will help someone to find a solution to the ruined brush issue and rejuvenate polyurethane covered brush!