Buying More Brush Time
Back when most paint was oil-based, we used to say, "If you're going to lunch, clean your brush. If you're getting coffee, don't worry about it." Now, some of these new low-VOC latex paints dry so fast, the brush gets stiff in a few minutes. To buy extra time, I'll add a small amount of latex conditioner to the paint, just enough to keep the brush from dragging.
Cleaning Out Latex Paints
I clean a synthetic brush as soon as the latex paint creeps up near the ferrule. Put some water in a 5-gallon bucket and swish the brush around to get the bulk of the paint out. Then, for the paint that's collected deep in the filaments, run them upside down under a faucet (slide 2) to make sure you get it all out. When the water runs clear, brush the filaments with a metal brush comb (slide 3), which straightens the bristles and coaxes out any bits of dried paint. Wire brushes also work well for this purpose, but they're pretty aggressive. In a pinch, I've also used a hair comb.
Mechanical brush spinners are a great way to get excess water out of big, 4-inch flat brushes, but for anything 2½ inches or less, I'll just smack out the loose water against a piece of plywood and form the brush back to shape with my hand. Then I store the brushes in a plastic zipper bag, or in their original packaging.
Cleaning Out Oil Paints
The first stop is a "dirty" jar, where the bristle tips soak in paint thinner without touching the bottom (slide 4); this way they won't sit in pigment and become bent. It's a trick my father taught me—he'd hang his brushes from a welding rod, but I just use a length of coat-hanger wire (below). If I need a brush the next day, I'll soak it overnight, then comb it out and get back to work. If I'm putting it away for a while, I'll still soak it overnight, then comb it, and dip it in a jar of clean solvent. After a quick flick to get rid of excess solvent, I wipe it dry on a newspaper or a rag. If I see any paint, I'll dip it again in clean thinner, then flick and wipe again.
I keep the dirty jar tightly sealed. When the paint settles, I'll decant the thinner into a clean jar. I never toss out solvent: It's wasteful, bad for the environment, and illegal besides.
TOH Tip: Whether you're using a brush or a roller, the rules for applying paint are the same: Keep a wet edge, lay a thin coat and use nice, long strokes.