View Full Version : Latest oily rag experiment

03-20-2019, 05:56 PM
I mentioned recently that my volume of painting has outstripped my space for drying oily rags so I'm looking for alternatives.

The usual advice is to put them in a bucket of water, but then what? We don't have a hazardous waste facility to drop things off and if I just put them in a plastic bag and put them out with the trash the water will eventually leak out/evaporate and then the rags will oxidize and start burning anyway (at the dump?).

So here's what I've been experimenting with...

... For this example I took 4 cloth rags from my studio and put them in the bucket and poured enough linseed oil in to saturate the rags, so they would all have the same amount. I then took one out to air-dry - that's the yellow one - yellow with linseed oil. They all looked like that before the treatment.

For the remaining three I filled the bucket with water and poured in a cup of driveway degreaser - it has powerful surfactants and detergents - chemicals which can attach to oils on one end and water on the other end so they break apart oil so it can be suspended in water and washed away. I swirled it around with a painting stick and let it sit for 10 minutes, then swirled it around some more and poured out the water in a snowbank on my property. It smelled strongly of linseed oil and was a pretty pistachio green because of the paint in it.
I then repeated this. The second time the smell and colour were much less intense. After a third treatment the water was clear and the photo shows the result - clean and white.
I then air dried the clean cloth and now it's soft and dry and feels like fresh rags. I won't reuse it though because I noticed something scary - You can see there's a little paint still on it. But on the dry cloth that paint is dry DUST. Without the oil binder I suspect it's just the pure pigment before they mixed the paint. Breathing pigment dust, especially of cadmium or cobalt, is dangerous. So I'm still treating this as hazardous waste. My town says I can put it out in the trash because "it all gets burnt". Is that OK?

Meanwhile the rest is in my soil as the snowbank melts. I live on 1.5 wooded acres, the site of a former orchard. so the soil already has arsenic in it. Is a little cobalt and cadmium going to hurt or should the waste water go down the drain?

Bottom line: this is a quick, easy way to remove the oil from your oily rags to eliminate the risk of spontaneous combustion.

PS - I think this photo would make an interesting painting but I'm still no good at doing printed letters, like on the oil and Krud Kutter.

03-21-2019, 01:44 AM
That seems like an awful lot of work to me. Couldn't you either just wash the rags (before the linseed oil becomes too dry) in the washing machine to remove the paint and then use them again? (Note that I haven't tried this and don't really know if it works or if it might cause a problem with your washing machine.) OR, perhaps the solution is what I use: Viva paper towels. They're great - they're strong and don't have the lint problem of other paper towels.

Harold Roth
03-21-2019, 06:39 AM
Don't put used oil painting rags in your washer. Stuff comes off inside your washer and makes it smell like oil, and then that gets on your clothes. Also, the rags don't get very clean. I tried it. Not a good idea. Maybe it depends on your washer and how dirty your rags are.

I use shop-cloth type paper towels I buy in mass quantities on Amazon instead. No lint like regular paper towels and I just put them in a small plastic bag, tie it shut, and throw them in the dumpster every day. So far the dumpster has not caught on fire.

03-21-2019, 09:24 AM
Oily rags are like oily paintings, best left to dry flat. Disposal of dried rags can be treated as dried paintings that are to be destroyed, burned in a steel barrel. Concerns regarding individual persons painting supplies are nonsensical in the face of industrial wastes. A single school being built in my area is going to waste more paint in building and painting it, than will be the waste of my entire lifetime of art. (More than just a few gallons... it is a big school) Everything in large quantities of waste is problematic, even the probably labeled “nontoxic” paints they might use. Plastic wastes are actually quite bad for the environment, acrylics going into our water supply is worse than some might think. It is all about quantity here.

The wastes from the detergents used is probably more dangerous to the environment than the oil or quantity of pigments that would go into the ground.

Edit: Wow, I correct myself, Krud Kutter is good stuff, very low environmental damage potential. Good find, will have to utilize some for breaking down oils sometime, just an alcohol based degreaser really... impressive.

03-21-2019, 10:25 AM
I wash lightly soiled rags with my brushes in Murphy’s Oil soap. They dry on the edge of the sink over night. For gunky clean ups or globs of paint, I use paper towels (sorry Earth!) and rags with accumulated staining. This just makes sense to me. No fire, less waste.

03-23-2019, 02:10 AM
Oily rags are like oily paintings, best left to dry flat.

I know, but as I explained, I no longer have the space. Since retiring I've become much more prolific in my painting, literally painting all day, all week. Also I've switched to solvent-free cleanup but that involves more oil and oily rags.

03-24-2019, 10:52 AM
You're right, oil paint and wood pulp paper products and cotton rags are hardly waster products. They are all biodegradable. Unless the pigment is lead of another toxic substance, you could even eat the paint! The linseed oil itself is edible.

By the way, my wife would kill me if I even suggested putting oily rags in her washing machine!

03-26-2019, 07:39 PM
Sorry if this is hijacking, but anyone know if it's a good or bad idea to clean dried oil out of brushes with that degreaser? Sounds like you could leave a brush in it overnight and it would be good after a swish or two.

03-26-2019, 07:51 PM
Degreasers of this type are basically just strong surfactants. They break up oils because they have a lipophilic and which attaches to the oil and hydrophilic end which attaches to the water. So I imagine they would be fine for cleaning brushes except for the types of brushes such as hog bristle that don't like water, but I've never tried it.

03-27-2019, 03:12 AM
Richard Schmid recommends Viva paper towels.