Friday, February 11, 2011

Save the Environment Brush Washing Method

In a letter to Robert Genn, Mark Gottsegen, a member of the subcommittee on artist's materials of ASTM International (originally the American Society for Testing and Materials) since 1978, wrote:

In the recent clickback regarding cleaning brushes, no one asked what to do with the left-overs from washing brushes. Down the drain? No, that's environmentally irresponsible - putting solvents and pigments into the waste stream is never a good idea. If you have a septic system, you will pollute it; if you have a municipal sewer, you will pollute it. If you are in a class or a school, then in the US doing this violates federal law; if you are an individual artist, doing this is just bad practice.

Collect the veggie oil, waste water (or sludge), waste solvents, dirty rags and paper towels (dried) and take all the collected waste to your community's hazardous waste collection station, where it is consolidated, incinerated and burned to ash. Then it is cast into concrete billets and encapsulated. Only then can it be taken to a protected, certified landfill. The cleaning part is the easiest. Being environmentally responsible is more difficult.
Mark Gottsegen sets out an environmentally friendly way to deal with brush washing in his book, The Painter's Handbook. I will try to describe the system in my own words, with a few of my own tweaks, as follows:

1. Get 3 large plastic buckets with lids (about 5 gallon size, which can be obtained from stores like Home Depot, Lowes or Rona) and one that is even bigger that you will use without a lid to allow liquid to evaporate (I use a smallish, inexpensive garbage can lined with a plastic bag for easy cleanup). I have also recycled those gigantic protein powder containers to use for A, B and C and that has worked well in that when you swish the smaller opening keeps the splashing in the container instead of all over your clothing.

2. Label the first three buckets A, B and C. Container D is the larger plastic container which will hold at least 10 gallons. You will also need a container with vegetable oil. I use a coffee can with a tuna can (which has holes punched in it with a nail) inverted on the bottom. You could use a glass jar or any other container. If you use a fancy brush washer, line it first with a plastic freezer bag to save yourself some messy cleanup later on.

2. Fill A, B and C halfway with water. Add 1 cup of liquid dishwashing soap to bucket A. Make sure to use a highly concentrated, good quality liquid soap for this as the cheaper brands are diluted and you have to use more for it to be effective.

3. Now for the brush cleaning method I use: First of all, dip your brush in the vegetable oil and wipe it on an old phone book until much of the color is released. Second, rinse the brush in the can to get more of the pigment out - this will eventually fall to the bottom of the container.

You can use any kind of vegetable oil for this, so I use whatever is cheapest. You can also mix some water with the oil if you keep the mixture in a jar and shake it up just before use and that will make it less thick. Walnut oil is nice to use as it is less viscous, but it is much more expensive. The only downside to using regular old vegetable oil is that you have to be sure to wash the brushes more thoroughly to get all that non-drying oil out.

Squeeze the bristles and wipe on a paper towel to get as much oil and pigment out of the brush as you can. Then, vigorously swish the brush in container A, then container B and finally container C. Wipe the brush on a paper towel or rag to see if any color remains. If it doesn't seem to be completely clean, repeat this process until clean.

When container A becomes too dirty, transfer the contents to container D and allow the liquid to evaporate, eventually leaving a dry cake of pigment which can be safely disposed of by taking it to your local hazardous waste disposal center. When your cleaning oil becomes unusable, it can be recycled in the same manner. Pour container B into A and pour the contents of C into B. Add another cup of liquid dishwashing soap to what is now in container A.

There you have it, an environmentally friendly method of cleaning your oil painting brushes that does not involve any pigments escaping into our septic systems or drinking water!




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