How to Clean a Natural Bristle Brush

This article was inspired by a question from Tom, who writes:

I just read Bob Flexner’s book “Understanding Wood finishing”. I was hoping you could help…. On page 27 regarding cleaning brushes he states that the last step in cleaning ANY brush is to wash in soap and water. It is my understanding that natural bristle brushes do not hold up to water. So how can I use water to clean it??? Is it that a short exposure time is ok?? Please help.

Many of you know that my preferred way of applying finish is with the wiping method. So my experience with brushes is pretty limited. That’s why I brought in Bob Flexner himself to answer Tom’s question.

“All types of bristles can be washed in water. Natural bristles don’t hold their spring for very long in water, so they don’t work well with water-based products. But there is no problem washing these brushes, and you really have to if you’re going to store the brush because its the only way to get all the residual finish out of the brush. Thinners only thin the residue. They don’t remove it.” —Bob Flexner

You can support Bob and The Wood Whisperer at the same time by ordering Bob’s book: Understanding Wood Finishing