Combustible Tung Oil

[Matthew Poeller]

I know, I know beat to death but I have a few questions.

Everyone knows, or at least most poeple do, that if you wad up a rag soaked in tung oil or other various sorts of oil that the temperature will quickly rise and the rag with start on fire. (due to the oxidation of the oil.)

I have seen David Marks put them in a bucket full of water, seen them spread out to dry and yada yada.

I have just finished the first coat of tung oil on a project and it is the first time that I have ever used it so here goes the questions.

1. Once you soak them in the water bucket what do you do? I would assume that when taken out to dispose they can possible go through the same reaction and the same risk is taken. So after I have them taken out of the bucket what do I do?
2. What about the latex gloves? Do I soak them in water too or can I just wad them up and throw them out? (I put mine in the water for right now.)
3. The brush, I have soaked it in thinner for right now but I will eventually want to clean it. Do I just clean like normal or should I just throw it out? If I throw it out should it be put into the water can too? If I fully clean and dry it do I have to soak the rag that I dried it with in the water?

OR should I just get a metal can, throw everything in it, light a match, and control the burn and be done with it.

OK so maybe I am a little paranoid but I have basement shop so a fire means that I loose my house and possibly loved ones.

Maybe I should have thought of this before I started with the tung oil.

[Cecil Arnold]

If you are really that concerned, go to a safety supply, buy a metal trash can made for just this sort of thing. They have self closing lids, are heavy gauge, and non combustible, usually painted RED. As far as the brushes, clean them, save the MS for later use in a metal can, and RELAX!

[Matt Meiser]

I spread them out flat on the concrete floor and let them dry out for several days, then throw them away. I use cheap throw away brushes when working with oil since I'll be following along with a rag anyway, so I just let those sit and dry then throw them away as well.

[Lee DeRaud]

I was under the impression that an air supply was required for this to be a problem. My solution has been to use the Scott "Rags-in-a-box" disposables and disposable vinyl gloves. After each coat, I wad up the "rags" in one hand, invert that glove over them, put the resulting wad in the other hand, and invert that glove over the whole thing. First couple times I did it, I put it out on the washer and checked them every couple of hours: no temperature rise at all.

I've mostly been using the Seal-A-Coat/Arm-R-Seal combo lately and have no idea how much actual "oil" is involved, but I've also done this with tung oil, same results.

Is this actually working as well as it seems to or have I just been really lucky?

[Matthew Poeller]

I do believe that you need the air supply. That is the only way that they will oxidize. I usually do the glove thing with everything else but was extremely worried about the tung oil.

I will get the metal combustible can soon but the store was closed when I went there tonight. I think that will ease my mind a little bit.

Unfortunately in my small basement shop I do not have the luxury of spreading them out on the floor. I would in effect have a carpet of used tung oil rags after a while.

When I take them out of the water I will seal them up tight and throw them out. I think that I will move the garbage can away from the house a little.

[Michael Perata]

I had a painting crew doing cabinets in a custom house using Dura Seal stain. It was Friday and the crew knocked off early.

Sunday, I was showing one of my houses next door and decided to check in on the other house. Opened the rear door and found the house was filled with smoke. Fortunately, the house was very air tight and with no air currents the fire burnt down through the first floor - about 5' x 5'. The fire was hot enough to melt an aluminum ladder.

The painters had thrown their rags against the baseboard in the dining room and just left.

The next day, Monday, after getting chewed out by their contractor, the painters started throwing the rags out in the back yard. They threw the rags against a rail fence, and the fence burnt down over night.

Moral of the story - be very, very careful with the handling of staining/finishing rags. (Yes - I changed painters afterwards.)

[Jules Dominguez]

Matthew, I've have had experience with spontaneous combustion occurring in large storage piles of coal and wood waste in paper mills and power plants. A combustible material in contact with air will oxidize. The oxidation process generates heat. It's a slow process when it happens naturally, as in a fuel storage pile, but because the material itself acts as an insulator, the heat in the center of the pile can build up until it reaches a combustible temperature, and then, voila! you have a fire.

Oil-soaked rags present a large surface area for oil to get together with air, so the oxidation is more concentrated and is even more of a hazard than with the solid fuels. If the rags are piled, they form their own insulator and spontaneous combustion can occur. If the rags are hung outdoors, as Jim Becker suggests, oxidation still occurs, but the heat doesn't have a chance to build up. I think the risk of spontaneous combustion, if any, is probably small or nil after they've had a few days for the oxidizables to oxidize.

As to soaking them in water, I have the same questions that you do. The material won't oxidize while under water, and can't reach a combustible temperature when wet. But the rags may still be dangerous when they dry out. I don't know.

I

[Ian Barley]

On the basis that the cloth is gonna be disposed of anyway I just put a match to them and let the burn happen under my control.

[John Hart]

...My solution has been to use the Scott "Rags-in-a-box" disposables and disposable vinyl gloves. After each coat, I wad up the "rags" in one hand, invert that glove over them, put the resulting wad in the other hand, and invert that glove over the whole thing. ...

Lee,

I do this exact thing too. I guess we're both lucky!

[Lee DeRaud]

On the basis that the cloth is gonna be disposed of anyway I just put a match to them and let the burn happen under my control.

That funny sound you just heard was a bunch of woodworkers slapping their foreheads in unison.

[Howard Acheson]

Couple of facts. To burn, it has to be an oil that is drying fairly fast. Pure, 100% tung oil dries so slowly that it should never build up enough heat to combust. The problem is most accute with BLO (contains dryers to accelerate curing) and oil/varnish products containing linseed oil like Watco, Minwax Tung Oil Finish (which contains no real tung oil--it's a linseed oil product) or others containing linseed oil.

Putting oil soaked rags in water will prevent combustion but preventing oxygen into the equation. But once you take them out of the water, and they dry out, you could have a problem. And, now you have a potential problem disposing of the contaminated water. Putting them into a seal container will prevent combustion by excluding oxygen but it also prevents the material from drying. Removing the rag from the container will again cause polymerization to start and now there is again a source of oxygen.

IMO, the best solution is to spread out the rags on a clothes line, lawn, driveway, etc. This will allow the chemicals to evaporate quickly and once dry and stiff, they are no longer dangerous and can be discarded in the regular waste. It's the wadding up that concentrates the heat of polymerization and cause the combustion. Spread out, they stay cool.

[Bob Stegemann]

I use old coffee cans that I fill with water all rags go under water. Every few weeks I toos the whole can water and rags.

[John Miliunas]

I spread them out on our gravel driveway and throw a few rocks on them to be sure they don't blow away. A few days later, once I make sure they're dry, into the trash they go. In the winter, I'll spread them out on the concrete part of my finishing room floor to dry and then pitch them. So far, so good.

[Norman Hitt]

I used to hang them around the back yard on different things, but they always seemed to get loose and blow all around the yard, , Buuuuut...Now, I have a "SYSTEM".

I salvaged a 4 x 4 cedar fence post when we put up the metal fence, and I "Planted" it in the ground in the back yard. I just use my trusty old Arrow stapler, (that you staple the fiberglass insulation paper with), and staple them to the post and let them blow in the breeze, and when they are all dried out I just jerk them off the post and throw them in the trash.

I got the idea from seeing a garden that had some "Poor-Boy Scarecrows" that were made from rags Stapled to a few posts he had scattered around to keep the birds scared off his "Favorite Munchies".

[Jim Becker]

I just use my trusty old Arrow stapler, (that you staple the fiberglass insulation paper with),

Naa...you use a staple hammer for insulation work unless you like your hand to become numb and fall off!! I still have mine from when I was "in the biz" and wouldn't give them up for anything!