Oily Rags Cause Fires?

[Derek Arita]

:eek:I know certain types of oil, left on rags, under certain conditions, can spontaneously combust. What oils do this? Under what conditions? Until now, I wasn't really sure what types of oil did this, so I have been discarding all oily or solvent soaked rags in the trash, outside.

[Erik Loza]

Linseed oil seems to be the most infamous for doing that.

Erik Loza
Minimax USA

[Derek Arita]

I've heard about linseed oil, I know that some things contain linseed oil, so I'm never sure. I even toss out rags with mineral spirits, cause I'm not sure.

[M Toupin]

Rags soaked with polymerizing (drying) oils will spontaneously combust under the right conditions. There's several polymerizing oils, linseed oil is probably one of the main culprits around the shop. And yes, it's easy to do. Place a couple of handfulls of lightly BOLd paper towels into a metal coffee can and set it in the driveway. In a couple of hours you'll have smoke, fire and a new appreciation for spontaneous combustion.

Mike

[Joe Hillmann]

All oils can do it if the conditions are just right. That is the reason you washer and dryer say not to use oily clothes in them. The washer doesn't get all the oil out then when you put it in the dryer it is possible for the heat of the dryer to the chemical reactions going that cause the oil to become a drying oil which will cause the oil and clothes to become hotter and hotter and hotter until a fire starts. And that fire can start many hours after the dryer is done running.

Just to clarify that, it isn't the heat of the dryer that catches the oil on fire. It is the heat of the dryer that starts the chemical reaction that allows the oil to self combust.

The oil that is most well known is linseed oil but you should take the same precautions as you would with linseed oil with any oil based finish you use. If they are oil based and they dry they are by definition drying oils and it is the drying process that cause the heat.

As far as the conditions needed they need to be in an area where the heat of them drying can't escape. One the oil is dry there is no longer a danger of it self combusting(of course a rag covered in BLO may take months to dry in humid or cold weather) If you throw a linseed covered rag in a garbage can you PROBABLY won't have a problem. If you ball the rag up when you throw it in the garbage can then throw more stuff on top of it so the heat it creates can't escape you are more likely to have a problem. I usually hang my oily rags on the clothes line outside until they are dry. It is probably overkill but there is no danger of fire that way.

[Sam Murdoch]

Also a few brands = Waterlox, Watco. when i doubt dispose properly as described above.

[Dick Mahany]

I was applying an oil stain to my deck and using cloths to apply it to the rails and spindles. They were in the sun and I noticed what looked like smoke coming from a few that were wadded up. When I touched them to move them off the wood deck they were too hot to hold!! I immediately kicked them off the deck and spread them out on the dirt. They were just about to combust Thankfully the garden hose was nearby. It happened quickly. The stain was a linseed based oil. Now I always spread out any oil soaked cloth outdoors on the dirt or gravel and let them fully dry before discarding them.

[Steve Rozmiarek]

I think some old oil based paints would do it, probably because of the BLO in them.

[Peter Aeschliman]

There's some really important advice above... The worst thing you can do is throw the rags in the garbage while wet. Lay them out so that as many surfaces are exposed to the air as possible, outside, away from anything flamable. Let the rag dry completely before you throw it in the garbage.

[Jim Andrew]

I knew a guy who got his garage on fire. He had used an oil based stain on his house, and afterwards piled the drop cloths in the garage. It caused a lot of damage, not confined to just the garage.

[Matt Day]

I don't worry about which ones supposedly do spontaneously combust - I make sure ALL my finishing tags are layed out flat to dry or hang over the edge of my trash can.

[Roger Rayburn]

It's not just the finishing oils. We had a spontaneous combustion at church. The culprit was determined by the fire department to be the liquid furniture polish wipe-down rag tossed on the floor in the furnace room. In a ball, they presumed, but they had no question about the source being the rag and the cleaning folks confirmed the furniture polish. Surprising to me was that the temperature in the furnace room would have been pretty cool, below 65 F. The fire department said that wouldn't matter. The spontaneous combustion formula doesn't require an external heat source. A rag or paper towel, oxygen, and oil. Combined they generate their own heat. And it doesn't take long. Cleaning crew left Sat after noon. Flower guild member found it and called the fire department just a couple of hours later.

[Tom Ewell]

Yep, wife was rubbing some Danish on a teak table down inthe basement, while she was working a "burning electrical" odor began emanating from no particular area.
Shut down the main, threw open the windows, got the kids out of the house. The odor failed to significantly dissipate so we began searching for the source.
Discovered a plastic bag smoldering below her workbench and managed to get it outdoors before it burst into flames. The bag contained some paper trash had managed to collect some of the oil (her story.... I suspect a rag was included but the evidence went up in flames and didn't care to investigate the remains. :))
Both of us have done finish work for decades and we, of course, had heard of combusting rags and the like, this was the first time to witness the event.
Needless to say, all non water based finishing materials are treated with extra-special care.

[Jeremy Hamaker]

Just to add my own sternly worded opinion: oily rags should be laid flat, on a NON-combustible surface such as concrete, dirt or gravel, reasonably far away from anything combustible, and pinned down to avoid blowing away onto something combustible. I would not let any oily rag dry out near, or draped over the edge of, a garbage can..

[Matt Meiser]

Or just burn them if your location and conditions make it safe to do so. I used to just take them out to the fire pit and light them.

[Mark Wooden]

Alkyd paints contain drying oils and can combust also. Spread the rags out flat until they dry, then dispose of them in a metal trash can you keep outside.

[John Coloccia]

Believe it or not, I had a potted plant spontaneously combust on my deck. Fortunately I had to come home to meet my landscaper to get some mulch put down, and oh hey look, what's that smoking over there? Apparently, just the right mix of peat moss and other stuff, a clay pot to hold in heat like an oven, a good hot day and just the right amount of moisture, and VAVOOOM. When I got close to the plant/tree thing that my wife executed, I touched it and it flopped right over. The roots were completely gone and it was just balancing on the trunk.

[Jim Matthews]

I apply Waterlox with an abrasive pad.

Between applications, I put it in a ziploc bag and squeeze out the air.
This gets wrapped in a plastic grocery bag, also twisted tight to keep air out.

I learned this from painters that would wrap their rollers in empty bread bags, between coats of paint.

When finished with a project, I take the same precaution with the applicators and put the lot in a sealed coffee can - away from the house.

I have secondhand experience with an amateur setting fire to his new wine store after a marathon refinishing session.
He left the still-damp rags in one of the yet-to-be finished cubbies he had built.

The shop was gutted by the resulting fire, but the commercial building was spared.
Only the sprinkler system preveneted a total loss.

FOUR rags used to apply a deck stain started the fire.

[Jim Rimmer]

I don't worry about which ones supposedly do spontaneously combust - I make sure ALL my finishing tags are layed out flat to dry or hang over the edge of my trash can.

I treat all finish rags this way, too. I lay them flat on the driveway until dry no matter what was on them.

[Steve Rozmiarek]

Believe it or not, I had a potted plant spontaneously combust on my deck. Fortunately I had to come home to meet my landscaper to get some mulch put down, and oh hey look, what's that smoking over there? Apparently, just the right mix of peat moss and other stuff, a clay pot to hold in heat like an oven, a good hot day and just the right amount of moisture, and VAVOOOM. When I got close to the plant/tree thing that my wife executed, I touched it and it flopped right over. The roots were completely gone and it was just balancing on the trunk.

That would look funny on a fire marshal's report!