How to Wash Paintbrushes Without Wasting Too Much Water

I'm planning to spend the weekend painting my house, and I'm not sure what to do with the brushes and rollers when I'm done. It took gallons of water to clean them the last time we painted, but maybe that's better than using the cheap, disposable kind?

It's true that cleaning your painting tools can be water-intensive. As with cars and dishes, though, there's a big difference between an efficient washing regimen and a wasteful one. Choose the former, and there's no reason to violate a basic tenet of green living: Thou shalt choose durable over disposable.

First off, make sure you're using water-based as opposed to solvent-based paint. Water-based paints, which account for the vast majority of the American market, have much lower levels of air-polluting volatile organic compounds. Plus, they don't require strong chemicals for cleanup. To find certified low-VOC paints, look to the third-party organizations Green Seal, EcoLogo or Greenguard.

To clean water-based paint off a dirty brush, you can use soap and running water -- a lot of running water. Most people wash their brushes with something like a five-minute rinse under the faucet, or about 11 gallons from the local reservoir. That's enough water per brush to do three loads of dishes in an ultra-efficient machine.

With a little extra work, you can cut down on the waste. Start by scraping as much paint as possible off each brush, then blot the brush on old newspaper. Fill two coffee cans with an inch of water. Swish the brush around in Can No. 1, and once you've dislodged as much paint as you can, rinse the brush in Can No. 2. Pour the dirty water from Can No. 2 into Can No. 1, refill Can No. 2 with another inch of fresh water, and rinse again. The dirty water in Can No. 1 can then be used as a pre-rinse for subsequent brushes. A representative for brush manufacturer Purdy estimates that this method requires just a quart of water to clean each brush. (The two-container method works for cleaning roller covers as well, though it'll definitely take more than a quart. A 2002 Danish study found that 3.4 gallons cleaned both a tray and a seven-inch roller washed in the tray, though that was without any manual pre-cleaning.)

If you're careful, cleaning and reusing old brushes saves water. After all, it takes a fair bit of water to manufacture a new paintbrush, even if it's the cheap and disposable kind. The bristles usually are made from nylon, polyester or a blend of the two. According to figures from the industry group PlasticsEurope, it takes between two and seven gallons of water to process and cool the nylon bristles that might be used in a 2 1/2 -inch paintbrush, the most commonly purchased size. Polyester would use a lot less, about two-thirds of a gallon. Either way, that's more than it should take to wash your brushes at home, and we haven't even considered the water used in other parts of the manufacturing process.

The manufacture of new paintbrushes also means greater usage of plastic or wood for the handle and metal for the ferrule (the part that joins the handle and bristles). Then there's the electricity that powers factories and the emissions and fuel use associated with transportation. Finally, discarded brushes add to the landfill burden.

So for the greenest paint job possible, the Lantern advocates buying a well-made brush, washing it efficiently and then holding on to it for years to come. Make cleanup easier with a few preventive measures: Wet the brush before you start painting and try not to dip it all the way up to the ferrule, where it's toughest to clean. On multi-day projects, washing out your brush isn't necessary; put the wet brush in an airtight plastic bag and store it in a cool, dark place, and it'll stay usable overnight.

Before you start worrying about cleanup, though, take a few minutes to consider another kind of renovation-related waste. According to the Environmental Protection Agency, 10 percent of paint bought annually goes unused; that's about 69 million gallons a year. (As Consumer Reports points out, that's enough to cover all five boroughs of New York three times.) Paint can be recycled, but the process can be costly. Use an online paint calculator to figure out exactly how much you'll need to avoid the hassle of dealing with leftover liquid at the end of your project.