Oil Soaked Rags - Spontaneous Combustion (1 Viewer)

[PAToyota]

Something worth watching...



Back in high school, my high school shop teacher did a demonstration with rags in a paint can. Over the years, I've seen / heard of a few fires in construction projects during painting phases.

The one interesting thing to me was that the temperatures weren't reaching temperatures you'd typically be concerned with.

 

[bj70bc]

wow thats some scary shiit....
i wonder if engine oil/brake cleaner etc is any different...

 

[e9999]

didn't watch the vid, but I always thought that spontaneous combustion only happens with exothermic drying oils, like linseed etc, not your normal engine oil-soaked rags.
However, even with the latter, you gotta be careful with sparks, thus the use of metal safety cans.

 

[PAToyota]

Yes, the video was about linseed oil - he tried raw, boiled, and a finish primarily composed of linseed oil. As mentioned, such oils generate heat as they dry. The situations I've seen have always been with oil finishes or oil paints. The video says that after twelve and a half hours the temperatures were all going back down - once the materials "dried out." But as he notes, that means that the fire is very likely to start in the middle of the night when nobody is around. The most recent incident locally was a new pizza joint that was finishing up construction - burned to the ground in the middle of the night a few days before opening when they were working to finish up all the painting.

Motor / lubricating oil doesn't "dry" and doesn't generate heat. I have wondered about - as mentioned - the combination with things like brake cleaner or other solvents, though. I've never seen anything about that. Such solvents are just going evaporate and aren't going to generate any heat for spontaneous combustion. However, the fumes are more likely to "catch" a spark than just oil.

I've heard people say to be careful with other exothermic materials - such as fiberglass resin or body filler. That if you have a significant chunk of it there is the possibility of igniting other materials. I haven't actually seen or heard of an actual incident with that, though, but can see how it might happen.

Clearly, best practices are to treat anything combustible with care. The risks of spontaneous combustion with certain materials increases the level of care.

 

[Redgrrr]

I’ve seen two houses burned down because of stain rags…

When I’m finished with them, I immediately burn them in a bucket or fire pit..

 

[Rugy]

On one of my projects in 97 the hardwood flooring guy stained the oak flooring on a Friday afternoon.
Saturday morning my oldest son and I went by to check up and see how the floors turned out.
At the front entry of the house a plastic 5 gallon bucket and melted and lit on fire overnight.
My son (6 at the time) was into Fireman Sam (UK kids show) at the time and I had him take the garden hose to fully extinguish the stain bucket. He was so proud that we was able to put out the fire.
The stain-bucket got hot enough to crack some of the 4" thick granite and the coping stone.
The stucco above the stone was a bit charred, luckily it was only the second scratch coat.
Luckily that was it for the damage, hardwood guy felt stupid and lucky at the same time.
Was a 1.9 M build in 97 and could have been a nasty insurance claim and lawsuit etc..
There in after all projects that had hardwood, stain rags had to go into a steel bucket and doused/flooded with water 30 ft away from the house.

 

[aztoyman]

I had heard of spontaneous combustion and seen videos but I never experienced it until it happened OUTSIDE of my garage fortunately when isopropanol soaked rags I had hung on the edge of an empty trash barrel to dry caught fire. No sparks or flames triggered it. It was just Arizona hot out.

There was no smoke of even flames noticeable at first. Something caught my eye and I saw the rags "going away" and I heard the sound. It was weird and really made me more cautious with any used shop rags since then.