Many of us have heard stories of oil-soaked rags spontaneously combusting and starting a fire. You may have only heard about it in the news, but it’s a very real thing and can cause a devastating fire. While factories and other large-scale businesses will handle the potential problem in a different way, we wanted to make sure the DUNN DIY community had easy access to this information, because a lot of our projects involve oil-based paints and stains! Your local municipality may have its own recommendations and/or programs too.
How does spontaneous combustion happen?
Rags with oil, solvents, oil-based products, and the like need time for the chemicals to dissipate. Unlike latex paint which dries with evaporation, oils dry through oxidation, which generates heat (and possibly fire). A rag will begin to warm as the oils oxidize. If the heat builds to the point of combustion, you'll have a fire.
How does one minimize the chance for heat build-up and combustion?
By allowing a safe way for the material/rags to cure without accumulating heat. Our recommendation follows an article found online by FineWoodWorking magazine.
Allow rags to lay out flat.
The key is for rags to be spread out, which allows for lots of ventilation. In a safe, outdoor area—hang or spread rags flat in a single layer. The rags need to be situated individually; avoid piles and folding.
Let the rags sit outdoors until they are stiff and dry. Only then are rags safe to dispose of, without the threat of spontaneous combustion.