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Been reading the AWR #39.
In page 43 it reads “Please note, that oil soaked rags may self-combust and have the potential to burn your workshop down”
So what does it mean? How likely is it? Would a piece of cloth soaked in Danish oil self combust under room temperature? or maybe in a hot day say 150°C?
I always just put them in the bin and sometimes the bin is full of saw dust.:oo:
Anyone?
When you wad the rags and then bin them they generate heat thru a chemical reaction.
Just spread them out to dry first or drop in a bucket of water.
How can I make it burn? I like to see it.
The best way to make them burn is to scrunch them up and toss them in a corner of your shed before going to bed, ready to throw out in the morning.
At about 1.00 am, your house will catch fire.
That's what happened to one of our neighbours anyway. Lost almost all their house, but fortunately got out OK.
It seems to be one of those very slow reactions, then when it gets critical heat.... whooof!
I always hang solvent or oil soaked rags spread out over the edge of my bin, then stick 'em in when they've gone all stiff as a two day dead cat.
Cheers,
P
:D :D :D
Ie Wongo, just after they're ready to cook......:D :DQuote:
Originally Posted by bitingmidge
Wongo,
I don't know how likely it is, but it is a real danger. Chances are, if you try to make it happen it won't:roll: .
Mick
Wongo, in our laboratory and factory, in fact any part of the building where there were likely to be (oil-based) paint soaked rags, we had buckets with water. Before knock off it was the employee's responsibility to put the used rags in these buckets. Anyone not doing that was regarded as a very short term employee:o.Quote:
Originally Posted by Wongo
Trust me, the problem is very real.
You said you wanted to find out and see it happening? Easy, just keep doing what you are doing (adding saw dust is an added incentive) and you WILL see it happening one day.
I saw somewhere an experiment where they tried to get this to happen. Under certain conditions (the specifics of which I have forgotten) it does happen in a repeatable way.
It's one of those things which is probably unlikely to happen but is easy to prevent, so not really worth debating.
Then again, ask the Mayor of Warsaw...
Ok I get the message. Thanks.:-
Next time I go camping I will bring a tin of Danish oil and a rag.:2tsup:
I have seen it happen. (MANY years ago on the TV show Mr. Wizzard.)
I have tried to make it happen with Minwax Antique Oil Finish but never succeeded. Wad the rags up, put them inside the latex gloves and then tossed out onto the driveway in the sunshine. Never a fire. I have some Tung oil that the next time that I use it I'll try. Usually I just let the rags dry flat out on the concrete floor where if they should burn there is nothing that would also burn.
Spontaneous Combustion test.
A weekend warrior mate stained something he made and then tossed the rags in a metal bin. Burnt half of his shed down and narrowly missed a classic car that was also stored in there.
I hang up almost anything to dry thats got anything other than water in it, even if its just hanging on the edge of the bin.
Thanks for that link Matrix, I have never seen it illustrated that clearly:2tsup:
Yes, you are quite right, just hanging up the rags to dry is also an option, one I use occassionally in my own shed.
and wait five hours...... by the time you get the fire lit, you'll have drunk so much beer you won't feel like tea!Quote:
Originally Posted by Wongo
P
:D
It happened to my uncle, a retired Engineer. Of course, having spent most of his life working with metal he had an impressive range of metal-working machinery in his 4-car "shed." Unfortunately, one corner of the shed was devoted to gardening... you know, packets of fertiliser, drum of 2-stroke, mower, etc. Being a very, very neat & organised bloke, (he even had layout marks on the floor for his mobile tools! :oo:) that "grotty section" was also where his trash- and rag-bins were kept.
Being retired, he decided to take up woodturning, and was doing a damned fine job of it too, if I do say so myself. :) His favourite finish? Danish Oil, of course.
I'm sure you can see where this is heading? We're not sure whether one of his garden products leaked and dribbled into the rag-bin or whether the rags ignited and some of those products combined into something nasty during the fire... but "spontaneous combustion" is a very poor description. "China Syndrome" would be more appropriate.
The fire was so hot that nothing was left of the steel shed, the floor slab had crazed and shattered and worst of all; none of the machinery was even remotely salvagable. Needless to say, his insurer's weren't happy about the situation and it took something like 5 years before they finally settled.
I look around at the mess in my shed and think "if it happened to such a neat bloke as him..." :oo: Trust me: I'm much more careful about storing used rags now. The risk may be fairly low but even so it's not a chance I'm willing to take. :no:
SMC forum members dalliance with self-combustion. "This is lucky Phil" :C
I tend to throw the oil/shellac/glue rags out on the grass, then pick them up when they are dried.
Works well. I'm too chicken to leave them hanging over the edge of the bin.
Quote:
Originally Posted by Wongo
Seen it happen twice. Once in a work truck and once in a shop. Truck was a right off the shop was saved cause the guy throwing the rags away got lucky and used a metal can instead of the usual plastic gabage can. I asked the guy if he used the metal can on purpose because of the danger and he said he had never heard of that before. The rags weren't screwed up tight just thrown in behind the seat of the truck and simply tossed into the bin. hey don't need heat as they make their own when the oil begins to dry. If there's enough insulation to allow a build up of heat they burst into flames. I always with out exception hang the rags up and let them dry for a couple days before I throw them away. Have tried to induce it myself to see how long it could take but found tying the rag in a knot didn't work. A hot day will only speed it up and make it more likely to happen.
Posted by Wongo http://mt0.woodworkforums.com/images...2/viewpost.gif
Been reading the AWR #39.
In page 43 it reads “Please note, that oil soaked rags may self-combust and have the potential to burn your workshop down”
So what does it mean? How likely is it? Would a piece of cloth soaked in Danish oil self combust under room temperature? or maybe in a hot day say 150°C?
What part of Hades do you live - 150"C . . .
Jedo
Hell!
Not I mean Queensland. :D
Thank you all for the reality check and links to the sites.
Have crumpled up rags before - not warm - no problem - therefore probably myth - having looked and now done some further digging I think I can say [my] "myth busted".
It may never happen to you but it is a real threat so why take unnecessary chances. Must admit I have been guilty in the past of not doing the right thing but this thread has given me the wake up call i needed.:2tsup:
If you want to try it, just spill some loctite 406 & wipe it up with a nylon rag. Bunch up the rag & toss it in a metal garbage bin.
Did that in the old factory one night, turned around 5 minutes later & the bin was smouldering.
When I told the dayshift boys, they didn't believe me, so they all tried it themselves & it worked every time.
What is the situation where the rags are place into a sealed metal container? I have tested this and found that there was no heat build-up in rags in the tin. But perhaps my experiments lacked something.
I keep my standard shellac applicator in a sealed small plastic container and have seen no heat build-up there either, and cloth does not harden-up.
Rags that I have finished with go out on the lawn before going in the garbage bin.
I do not throw out rags used for tool cleaning until they are sufficiently dirty, these do not have non-drying oil on them - only dirt and WD40 usually. They are not in a sealed container, and I understand do not self-combust.
I think that shellac might be different as it cures more because of the solvent evaporating rather than a chemical reaction with the atmosphere like dansih oil etc. Another thing about having it in a sealed metal container is the lack of oxygen to start (or maintain) combustion.
Ping
Paul Chapman has posted a link to this experiment on the Woodwork UK Forum: http://wildwoodsurvival.com/survival...l05/index.html
So yes, Wongo, you can do it. I imagine that if the cloths were of a more combustible fabric than cotton (eg polyester) the experiment might be more spectacular!!
This effect happens specifically with the so called "drying" or polymerising oils, like linseed and tung. These are traditionally ingredients in the so called Danish or Scandinavian oils.
However, many commercial so called "danish oils" are really far closer to wipe on poly in formulation, and may not show the effect to the same extent. With high levels of drying oil, however, it can definitely happen.
Requirements are:
High drying oil content.
Large surface area; i.e. rags, sawdust ( to allow oxidation to take place over a large area)
Insulation to allow heat build up; i.e. piled up or bundled together, and enclosed in bin.
Along with this, critical mass. Far more likey to happen with a big pile of rags than with one small piece.
Given the above, temperatures well above the 150C will develop in a relatively short time, until the ignition point of the combination of rag and oil is reached, then "wooshka"
To the extent that in the edible oils industry, when processing linseed, it is necessary to blend it at least 50/50 with other non oxidising oils, to reduce the risk of ignition of used filter earth .
regards
Or, for the impatient, mix Condy's Crystals (Potassium Permanganate) with Glycerine. Only takes a couple of minutes. Also fun for the kids.
:doh: My wife used 'Danish oil on our household furniture some weeks ago during a cleaning spree and placed the oil soaked cloths into our new 120 litre plastic 'Wheelie bin' for Council pickup.
I went out into our backyard after watching a movie at about 10:30 pm and the backyard was lit up like 'Luna park' and was filled with black acrid smoke.
You guessed it the bin went up in flames
I can't understand that the neighbours didn't kick our door down as the whole suburb was smothered in black smoke and the smell of burning rubbish
Fortunatley only the bin was completly destroyed along with our household rubbish and the corro. fence was blackened [nothing that a coat of paint didn't fix].
I recently retired from the local Council so I still had some contacts that I could approach to replace the bin after some explaination and good humoured chiding that was to be expected!
The outside temperature that day was around 35deg in the shade or better:no:
Thanks Ron, that reminded me that I had left my BLO cloths in a pile under the skylight in the shed!
Cheers