Linseed oil danger

[Stormin Mormon]

Linseed oil and rags -- need to dispose properly.

Otherwise, you'll need home repair.

Christopher A. Young Learn more about Jesus

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[recyclebinned]

Self-Heating In Yard Trimmings: Conditions Leading To Spontaneous Combustion

[Frank]

Lot of mushroom houses around here and one of the big suppliers of compost always has fires. I haven't heard anything in several years about it but local fire company was getting pissed and hitting composter with some of the expense of constantly putting out his fires.

[Tegger]

[e-mail] wrote in news:ba99b7ee-b731-424f-93ff- [e-mail]:

Same thing can happen inside hay bales if the hay is too wet. That's why Farmer Brown lets the hay sit for a bit, and flips it once, before baling it.

I've even seen wet garbage get pretty warm inside.

[Tony Hwang]

Hi, Same with Peat mos, compost pile, etc.

[Harry K]

rude and crude paint shed at a agricultural equipment plant where I worked. Regular job was to scrape the floor to get rid of the paint build up - regular dumpster fires from it.

Harry K

[nestork]

For anyone that gives a $#|^ about it...

The reason that you can have a fire start in pile of rags damp with linseed oil, or a linseed oil based paint is that linseed oil is typically at least 50 percent linolenic acid, which is shown in this diagram:

The double carbon=carbon bonds between the 9th and 10th, 12th and 13th and 15th and 16th carbon atoms means that the 9th, 10th, 12th, 13th,

15th and 16th carbon atoms will only have ONE hydrogen atom bonded to them, whereas, the carbon atoms in the /\/\/\ part of the molecule will each have two hydrogen atoms bonded to them. By definition, that means that linolenic acid is an "unsaturated" fatty acid cuz you can fit more hydrogen atoms onto it. And, each of those double carbon=carbon bonds is an "unsaturated site".

There's a reaction that occurs in nature called "auto-oxidation", and what that means is that if an oxygen MOLECULE (O2) passes between two unsaturated sites in close proximity to one another, that oxygen molecule will spontaneously break apart to form two oxygen atoms, and each oxygen atom will form a C-O-C crosslink between those two unsaturated sites. It's that spotwelding together of unsaturated sites within a linseed oil molecule and between linseed oil molecules that causes linseed oil to transform from a liquid to a solid in about a month's time; or about 2 or 3 days in the case of "boiled" linseed oil, PROVIDED it's expose to oxygen.

Now, as it turns out, that auto-oxydation reaction is an exo-thermic one. Energy is released when an oxygen molecule breaks apart and becomes a pair of C-O-C crosslinks, and it's that accumulation of exothermic heat that can raise the temperature inside a pile of rags damp with linseed oil above the kindling temperature of cotton. When that happens, the pile of rags spontaneously starts burning.

PS#1: Window glazing putty is nothing more than linseed oil mixed with clay. And, just in the same way that a gallon of linseed oil based paint will form a solid film on it's surface during storage, the surface of glazing putty that's exposed to air during use will harden up by that same auto-oxidation reaction. Oil based paints will absorb up to 17 percent of their weight in oxygen molecules while you're painting. Once the oxygen has been absorbed into the paint, a film will form on that paint in storage. About the only way of avoiding the formation of that film would be to keep the paint cold (by putting it in your freezer) to prevent that auto-oxidation reaction from happening (or slow it down dramatically).

PS#2: If you ever hear some monkey on TV talking about "Omega Three" fatty acids, all that means is that the THIRD carbon atom from the end of the fatty acid has a double carbon=carbon bond. It's just a different naming system. Chemists start counting the carbon atoms from the carboxyl group (which is why the furthest carbon atom to the left is labeled "1") while nutritionists and food scientists start counting the carbon atoms from the other end (which is why the furthest carbon atom to the right is labeled "omega" or "w". So, looking at the diagram of linolenic acid, the third carbon atom from the end marked with an "omega" or "w" symbol has a double carbon=carbon bond on it, so linolenic acid is an "omega-3" fatty acid. It's also an omega-6 fatty acid and an omega-9 fatty acid as well. So, what seemed to be so highly technical turns out to be pretty simple.

Obviously, I'm not very busy right now...

[fred.flintstone]

I've had some manure burning underground for about 2 weeks now. I filled in a ditch with some horse manure, then covered it with soil, about a year ago. Two weeks ago I burned off some brush and other farm trash such as used twine and feed bags, along the edge of that filled in area. Since the weather has been dry, apparently the manure underground began burning. All I notice is small holes in the soil with little puffs of smoke coming out. We have had two significant rains since and it's still burning. The soil is sinking at the edge. It's not hurting anything, just stinks a bit. It cant spread to anything, so I'll just leave it burn until it goes out. I'll have to add more soil later though.

I know of a much larger manure fire that happened about 15 years ago. The guy's barn was full of deep manure after he sold his cattle. The manure stayed in that barn for several years. One night a tornado destroyed the barn and several other farm sheds. He took a bulldozer and pushed all of it down into a deep ravine, and set it all on fire. It was one huge fire to see. This fire occurred in June. In November I went to his house for Thanksgiving, and that manure was still smoking and stinking. He said the smoke stopped in January after at least a foot of snow fell.

[Ed Pawlowski]

This is a great conversation starter at a cocktail party.

[Stormin Mormon]

Do chemical engineers party? I'm not sure I've seen many Dilberts there.

Christopher A. Young Learn more about Jesus

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This is a great conversation starter at a cocktail party.

[Han]

Ed Pawlowski wrote in news: [e-mail]:

Hey, wait a minute. That stuff used to be my bread, butter etc.

[Han]

"Stormin Mormon" wrote in news:PT1% r.64853$ [e-mail]:

Biochemists do party. Very productively. The inspiration you get at a party! Priceless ...

[nestork]

No, if you want a great conversation starter to chat up the ladies at a party, ask them why their blue jeans are darker when they're wet.

And, to prove that your explanation is correct, put a drop of water on a dry paper towel. The wet spot will look darker that the surrounding dry paper towel.

Now, hold that paper towel up to the light and you'll find that the wet spot is now much brighter than the surrounding dry paper towel. Since cotton is almost pure cellulose and wood (and hence paper fibers) are mostly cellulose, whatever is making the paper towel darker when it's wet also makes blue denim darker when it's wet.

If you want a great conversation starter if there are only guys at that party, ask them why latex paints darken in colour as they dry.

Post again when you give up and I'll explain it all.

[David Kaye]

"nestork" wrote

You've hit on a scientific method for determining the candlepower of different light sources. Put one light source on one side of the paper towel, and put the other light source on the other side. Move them back and forth (toward and away from the paper towel). When you look at the towel and can't see the wet spot anymore, then you've determined the relative brightness of the two light sources. The one closer to the towel is the dimmer source.

[Ed Pawlowski]

That will be very soon. I'm guessing it has to do with reflectivity but I've not look up anything yet.

[Larry Fishel]

I'd bet topping off the can with nitrogen before sealing it would do the trick. I assume CO2 would work, but I'm less confident and not curious enough to research it at the moment. :)

Maybe you could set the surface on fire, then lay the top on the can and let it seal itself. (Only if the can's mostly full, otherwise it might collapse.)

[Art Todesco]

I visited a friend's house where he was doing some remodeling, etc. On his plastic laminate kitchen counter, there was a burn about 5" in diameter. I said something like, "placed at too hot pot there?" and he said, no. He had a linseed oil rag there and apparently it self combusted. Luckily, there wasn't any other combustibles to spread the fire, other than the small piece of rag itself. Lesson learned.

[Stormin Mormon]

Ouch! Glad the plastic surface didn't light up.

Christopher A. Young Learn more about Jesus

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I visited a friend's house where he was doing some remodeling, etc. On his plastic laminate kitchen counter, there was a burn about 5" in diameter. I said something like, "placed at too hot pot there?" and he said, no. He had a linseed oil rag there and apparently it self combusted. Luckily, there wasn't any other combustibles to spread the fire, other than the small piece of rag itself. Lesson learned.

[nestork]

I use Ronson butane, which you can buy for refilling butane lighters at any smoke shop. Butane is heavier than air, so you'd think it would form a blanket on the surface of the paint and physically separate the paint from the air trapped in the can.

But, that only works about 50% of the time because as long as the can is open, the linseed oil is absorbing oxygen from the air, and the more oxygen absorbed, the thicker the solid film that'll form in storage will be.

Whenever using any kind of "oil based" coating, like a drying oil (like linseed oil, Tung oil or Danish oil) an alkyd paint, a real varnish or an alkyd based polyurethane "varnish", it's best to pour off what you think you'll need, put the lid loosely on the can, use a short piece of tubing to inject some very cold butane under the lid, wait for the butane to boil off into a gas, and then hammer the lid back on. That way you minimize the time of exposure of the liquid to air.

It's important to wait a few second for the butane to boil off into a gas. If you don't, the butane will boil off into a gas inside the sealed can, and the lid can come off with quite a bit of force.

[DerbyDad03]

d to dispose properly.

I hope the laminate was supposed to be in the "Before" set of remodeling pictures, not the "After".