I read on here, on the HAMB, that a great treatment for bare is boiled linseed oil and acetone, mixed 50/50. So I tried it, liked it and did the whole car. When finished, I had an empty plastic container and saturated rag. I made sure that there was no material left in the cup and tossed both the rag and cup in my plastic shop garbage can. The next morning, I opened the shop door to a cloud of smoke, pretty thick. So I closed the door and called the fire department. We then spent 2 hours looking at everything we could, but found...nothing. The next day, my buddy who shares the shop, called me and said "I found it", it being the ignition source. The plastic garbage can had the bottom burned out of it. Luck has it that it was away from anything flammable, outside of the can. A little research told me that the linseed oil will spontaneously combust if exposed to oxygen, which happen to me. So, beware!
Problem with it is putting the rags in a container where heat can build up. I open the rag up,and let it dry on old concrete out side for a couple days.You got lucky.Ive seen houses lost to poor linseed storage.
Ryan almost burned down his shop in the exact same way Sent from my SM-G965U using The H.A.M.B. mobile app
A few years back I was detailing my Chevy pickup for a show. Polished the aluminum mags....I threw the old black rags in the trash can. Then I used Linseed oil on the wood in the pickup box....I threw the soaking wet rags in the trash can which was outside on a 95 degree day. Sat down with a buddy to have a beer when we noticed the trash can smoking. I opened the lid and whamo…..instant fire. Moved the trash can and got the garden hose real fast. My wife always reminds me to never mix chemicals. Gary
I did the boiled linseed oil treatment on one of my Studebakers and luckily read about that spontaneous combustion thing before it could happen. I would certainly of done the same thing you did. I just got lucky. Who would think that would happen. Glad it didn't burn down your shop. With all the sparks I make I live in fear of that.
Any rag that has been soaked in an accelerant goes outside to outgas. BLO is the worst by far, but most of them can be dangerous in a shop can. We also have a steel springlid rag can in the shop for oily rags. I also did metal panel at least wainscott high and sealed all the joints with NP1 urethane so a spark can't roll behind the wall panels. I waited 25 years to build my shop... I'm extra cautious about accidentally burning it down!
It seem that most of these fire stories revolve around linseed oil. I go through bags of the white Home Depot rags in the shop, mostly covered in grease oil or solvent of one sort or another. Always concerned when it comes to disposing of the used ones but have never had a problem. I wonder if the linseed oil is the main culprit of if I have just been lucky.
Here is the write up from @Ryan . This is great info for those of us that didn't know. https://www.jalopyjournal.com/?p=34205
Boiled linseed in rags is the culprit and with the right conditions generates enough heat to self ignite. Google "boiled linseed oil spontaneous combustion". We were using boiled linseed for corrosion control in an tube air frame. Someone told us to be careful in how we dispose of the linseed oil rags as they can spontaneously combust in a garbage can or in a pile. We were lucky as we learned the risk mid project. The shop was heated with a wood stove so it was easy to dispose of the rags. https://abcnews.go.com/US/officials...ion-risk-linseed-oil-common/story?id=40788665
Petroleum oils don't do that. Only drying oils. Linseed is the most common but other finishing oils will do that. I think I've mentioned this before but: back in the mid 90s I was working a building we bought for an antique store. The main floor was 74x74 old growth yellow pine, vertical grain. Beautiful but needed some attention. After cleaning and repairing I started the finish work. Mixed 5 gallons on linseed oil, 5 gallons of thinner and 5 gallons of varnish. with that much area I just put it on with a mop, squeegeed it out evenly and let it soak in. Then used a dry mop had to pick up the excess. Now I knew of the spontaneous combustion issue as my high school woodshop teacher made a big point of that. I went to lunch not thinking it could happen that quickly. Came back a hour or so later opened the door, picked up the mop and it burst into flames! Luckily nothing else caught fire and I just threw it outside. The larger the volume of cloth, the more it contains the heat. Big mop head. Lesson learned
I just bought a can of this Saturday, so timely advice, thanks! I'd always heard about the oily rags bursting into flames, but didnt realize this type was worse. I normally throw rags in the stove anyway, but I'll be sure to make it point now.
Spontaneous combustion can happen to lots of materials.Years ago before we round baled hay ,and left it outside it was important to dry it,and store the square bales in the barn correctly.If you packed it tight,and it was wet it would burn the barn down.To this day if I fill the yard cuttings plastic can full of grass in a couple hours I can come back,and put my hand in,and feel the heat building.I keep the can away from the house!
I'm surprised it's still legal. It's not my opinion that it should be, just that it requires special handling and not everyone is aware of the danger. Some people don't even believe it is a problem. It's used by luthiers on guitar fretboards, as it makes a hard durable finish. "Yeah, I've heard that, blah blah." Well, good luck then.
Thanks for sharing this. I had no Idea! I used Linseed oil on my bed floor and probably threw the rags in the trash- Never again will I do that! I guess I was lucky....
I always put oily rags or ones that have gas or thinners outside to dry.If no longer useable-burn barrel.
Having been in the business that sells solvents and thinners the manufactures always impressed the importance of storing old rags that had been saturated with flammable solvents to put them in sealed metal containers due to the possibility of spontaneous combustion. If you look at the container it will warn you about the fact, you are a fortunate man you didn't loose it all. HRP
I remember that well as I've had the same thing happen but thankfully as well as with Ryan mine was in the corner of a concrete walled tin roof shed! Sent from my LM-V405 using The H.A.M.B. mobile app
The thing with linseed oil is you would die from boredom trying to light the stuff with a match. It will barely burn. But when it dries on a rag it produces a great amount of heat that makes the fire. If you dry your rags flat outside they probably won't catch fire because the surface area. When they are balled up thats when they build heat. The best solution I have found is to soak them with water then lay them flat somewhere away from flammables. I've seen first hand several very serious fires started by spontaneous combustion.
Have a friend who lost a 32 foot sailboat to fire. He had been refinishing the teak trim with teak oil and at the end of the day stored the rags down below anticipating coming back in the morning to work some more. Raining in morning so didn’t go back to boat for a couple days. Fire started in interior and was fully ablaze when discovered. Boat was a total loss but could have wiped out a whole marina if the fire had started late at night. As a result I always dispose of oily rags in a outside can.
I'm one of those who always tries to put any rag or paper towel that has any oil, grease solvent outside spread out on something before tossing it. Spontaneous combustion was one thing my shop teacher was hell on wheels on when I started auto mechanics class in the 10th grade. That was mostly proper storage of grease rags but he did cover it all. Had a hay stack on the dairy I was working on burn down and we lost over 100 large 1000 lb bales in that one. That was beside the hundred or so we managed to move away from the stack. The guy who leases our place and has all 70 acres in alfalfa uses a temp probe and a moisture probe to check the bales in the field while and after he is bailing. Usually it is someone who gets in a big hurry and bales hay that hasn' cured long enough in the field that gets in trouble with stack fires. When I was doing the maintenance purchasing for a big fruit juice and apple sauce plant I bought throw away chip brushes for what ever paint projects the people in the plant did and stressed that they left them laying out so they would dry before throwing them away. Two fold no fires from what was on them coming into contact with paper and what not in the can and combusting and no paint cleaners or solvents in the processing plant to cause contamination or get on paper towels.
I don't care what it is that I put on a rag. It gets hung out on my chain link fence for a day or two. Whether gas, water, linseed oil, any type of wood finish, coolant, or even brake clean or carb cleaner,. they all can start and accelerate the decomposition process, causing spontaneous combustion, and a total loss of a building, (or boat), as mentioned above. Roger
Example of how time and progress changes things. Back in the 60s it was well known by everyone that you don't throw linseed oil soaked rags in trash. Even had regular PSA announcements on TV and radio to that effect. It was a universal danger since all varnishes and most paints were linseed oil based. Water based paints were in their infancy and really crappy. Urethanes and acrylics were unheard of. Even most furniture polishes and many other household maintenance products were linseed oil based and a danger. One of linseed oils great properties is that it dries and seals in the finish it provides. This drying process is exothermic so when a soaked rag is confined, it starts drying and accumulates enough heat to combust. Nowadays modern resins have replaced virtually all of the linseed oil so no need to worry. the younger generation still needs to be informed of this danger as this thread highlights. The proper way to dispose of these rags is in a sealed metal can. big hassle but that's the way old-timers had to do it.
Guys- EVERYONE- dip those rags in water, then set them on a flat surface outside to dry. THEN, place them in a covered can or flammable resistant trash can with the lid on. BE SAFE.
I have finished all of my old military firearm stocks ( wood only for me ) in BLO and mineral spirits mix . Apply everyday for a month , then every month for a year , then one time a year for life . The stuff will heat up quickly when applying with your hands while rubbing it in . All my used rags go to the wood stove or fire pit . The cans with the spring shut lids are your friends . I remember seeing one in the boiler room , rags ignited , the lid would belch until the fire was out from lack of oxygen present . Safety first , we all forget or take it for granted . Thanks for the reminder post , I needed it .
I had an old towel that had some grease and oil stains on it in the side box of my semi truck. I was using it as a mat to keep grease and oil off the floor, it somehow got shoved back in the pocket into a wad. One day going down the road I began to smell smoke, stopped and got out hunting the source. Was surprised when I found that old towel smoldering in the side box! The vibration had been enough to cause it to flame up. So be careful if you carry a rag in your cars, make sure it’s clean and throw it away when it gets dirty!
I can remember Ohio state law requiring automotive shops to have a metal can with a self- closing lid for the disposal of oily and greasy rags, count me in with the others who put them outside to dry. I have seen them get hot and start smoking in the past, and had a friend who lost most of his house and belongings to a fire caused spontaneous combustion of oily rags. The fire department gave him a hard time over it also, and wanted him charged with arson.
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