How do people actually dispose of acrylic paint water?

July 21, 2021 1:34 PM

I think the Internet is full of lies when it comes to advice on how to dispose of old paint water.

I have been painting more (mostly acrylics) and every session I toss out about a half gallon or more of dirty water that my brushes have been washed in. This is bad for both my sink and the water supply! I googled and the advice I saw most often was to dump the dirty water into a bucket and let the water evaporate so that the paint is left behind.

I have been attempting this, in Texas, in the summer. I don't think the pace at which it evaporates is enough for this to be a realistic solution. Are people actually doing this? If not, how are people really disposing of their old paint water?

posted by tofu_crouton to Sports, Hobbies, & Recreation (7 answers total)

Best answer: Have you seen this video? I used to pour mine down the drain. Until now.

But it also might be worthwhile to check with your local wastewater entity. They can do some impressive water treatment.
posted by biersquirrel at 1:52 PM on July 21, 2021 [3 favorites]

I don't know the name, but there is a product you can buy to add to the paint that is supposed to speed up the drying process. I think you add it to the paint and leave the top off.
posted by jtexman1 at 2:18 PM on July 21, 2021

My tattoo artist uses slush powder to gelify leftover ink and water so that it can be thrown away in a regular trash can. I don't know if that solution is as viable for you given the volume of liquid that you're dealing with, but maybe a combination of evaporation + slush powder will work. You might also look into commercial spill absorbing granules.
posted by mezzanayne at 2:36 PM on July 21, 2021

Best answer: Here's printable instructions from Golden Paints outlining the process shown in biersquirrel link. I've used it, since I have both of the chemicals (for gardening purposes) and don't like having a bucket of waste water hanging around (due to pets).
posted by bCat at 3:15 PM on July 21, 2021 [2 favorites]

Best answer: Golden also sells a kit with everything you need.
posted by jimw at 9:52 PM on July 21, 2021 [1 favorite]

Best answer: Living on a septic tank, I didn't want to put photographic fixer and wash water into it: silver ions would kill it.

It went into black 5 gallon plastic buckets with hardware cloth tops, rolled on the edges to hold it onto the top of the bucket. A muffin fan lying on top of the hardware cloth, blowing down into the bucket, powered by a small solar panel nearby greatly accelerated the evaporation rate, and when it was dry, I just scraped it out of the bottom of the bucket, wrapped it and binned it.

I used this same system for the water used to clean paintbrushes of latex paint.
posted by the Real Dan at 12:55 AM on July 22, 2021 [2 favorites]

Response by poster: I had seen Golden's instructions before but I was really hoping for something less complex. It sounds like, based on bCat's experience, that this is something that people really do go through with, despite its complexity!

I checked my city's waste handling options and I can drop stuff off there, but accumulating buckets and dragging them over to the edge of town is probably more effort for me (without a car) than the Golden method.

I do like that the Golden method is adjustable. Use a lot of paint? Just get a bigger bucket!
posted by tofu_crouton at 6:01 AM on July 22, 2021