Monday Morning Art School: cleaning your brushes

Don’t expect brushes to last forever. But cleaning them regularly means they will last a good long time.
A constant, revolving mess.
A few weeks ago I wrote about what different shaped oil painting and watercolorbrushes were used for. A reader asked me to follow up on the care of brushes.
That’s rich, I thought, because I’m the worst abuser of my own brushes, especially when I’m on the road. There’s never a utility sink available, and it’s not nice to repay your hosts by washing brushes in their kitchen sink. I have been known to shower with them and clean them with shampoo, since they’re usually no dirtier than I am. Mostly I wrap them in plastic and hope for the best. And the best, after a week in a hot car, often isn’t very good.
Wrapped in plastic, hoping for the best.
The cardinal rule of brush care is to not let them stand in any kind of solvent—mineral spirits or water. That includes during painting, which is why a small, swinging solvent holder is such a great idea—it’s impossible to leave a brush in it.
Image result for "Carol L. Douglas" watercolor
If you paint out of a moving car, as I did here, you have to wait to clean your brushes.
Let’s start with watercolor brushes. In general, they need to be rinsed when you’re done, shaped back into their proper form, then allowed to dry flat. This is where a brush roll comes in handy. Pay particular attention to rinsing them if you paint with saltwater or use alcohol to prevent freezing.
Fine hair brushes can be washed with mild soap. However, the only situation where that would be necessary is if you’re committing the faux pas of using your watercolor brushes to paint in acrylics. If that’s the case, on your own head be it, as the Psalmist wrote.
Soap is not detergent.
Both are emulsifiers known as surfactants. These allow oil to be lifted out with water. That’s why they are both capable of cleaning your hair, although we generally use a different kind of surfactant—shampoo—for that.
Soaps are made from natural ingredients like plant oils or animal fats. Detergents use synthetic bases, and they have additional surfactants added to increase the oil-stripping. This is why we don’t generally use detergent to wash our hair—it’s too good at removing oils. The same is true for our brushes.
Soap, by the way, dates back to 2800 BC, whereas detergent was formulated during a World War I soap shortage.
Soaking them in coconut oil can sometimes loosen up dried paint.
If you left your brushes standing and they’ve started to harden up, detergent won’t work any better than soap at softening the mess. I sometimes pre-treat them with coconut oil when I can’t get the paint out. Masters Brush Cleaner also manages to soften up dried paint without using dangerous chemicals.
A few years ago, a friend sent me a sample of a product she likes for brush cleaning: War Horse Saddle Soap. This is a glycerin-based soap and is now my preferred brush soap, not least because they’re a family-based business using safe and sustainable materials.
However, I think any saddle-soap or brown soap like Fels-Naptha works. For that matter, I’ve washed a lot of brushes with the sample soaps available in hotel rooms. One product that doesn’t clean brushes well is Dr. Bronners Organic Pure Castile Soap. It’s a pity, because it smells good.
The only secret of brush-cleaning is to get to them fast. Get as many solids as you can out with mineral spirits; that will prevent clogging your sink. Thoroughly coat them with soap, inside and out, and wash them with a rag, not your bare hand. (Even the least-toxic of pigments shouldn’t be ground into your skin.) The brush is clean when the water runs clear, and not before.
Don’t expect heavily-used brushes to last forever. They’re made of hair and they wear out. In fact, most of my filberts started life as flats. But by cleaning your brushes regularly, you’ll ensure that they will last as long as is possible.