How do you dispose of BLO rags?

[John Christiansen]

Light on fire and throw them into the neighbors yard.

Well except for the neighbors yard part, this is the most sensible suggestion for those that are able to.

I have both an incinerator and a fire pit in my yard. I just walk over to one of them, light the rag up and toss it in. No muss, no fuss, job done.

[Jason Roehl]

Looks like this thread might save a couple of basements.

I am surprised at just how many of you have direct experiences with these fires. Thanks for sharing those with us.

So, to recap what I have heard so far:

1) hang rags outside to dry (far away from structures).
2) put into covered metal cans that are half-filled with water.


Question: Why wouldn't these rags self-combust outside while hanging up to dry - or sitting in an open metal trash can like Terry has? That would make me a bit nervous as well.

And I think my method of using a ziplock bag filled with water may not be the safest either. If the bag breaks and leaks out the water I could be in trouble.

Thoughts?

The problem is not with just any solvent-based product. The problem is with any finish that contains a drying oil such as danish oil, tung oil, walnut oil, BLO, and others. These oils oxidize (react with oxygen) in the curing process, which is a chemical reaction that generates a fair amount of heat. Spread over a project, it is not a problem, but when you soak a rag in it and crumple it up, the heat is somewhat trapped by the rag, with a plentiful supply of oxygen still available. Since the heat has no way to escape, it builds up to the combustion temperature of the rag and/or remaining solvents.

Your plastic bag method would continue to work, as there is no oxygen available to the rag. But, if the bag ever leaked out....

Standard method of disposal is to partially fill a metal container with water, put the rags in there, and put on a tight-fitting lid. Laying or hanging them flat works also. Some would be understandably nervous about doing this in their shop, but as long as they are in a single layer laying flat or hanging, there's really no danger of heat building as they dry. (I'd still do the trashcan thing, or lay them outside...winter weather is fine).

BTW...Not all painters are that ignorant....

[Steve Clardy]

Light on fire and throw them into the neighbors yard.

Ha Ha. Best response yet!!!

Mine go in the wood stove. Steve

[Michael Perata]

BTW...Not all painters are that ignorant....

Agreed. Fortunately/unfortunately I live in an area with a significant population that does not use English as their first language. Most are very hard workers who do high quality work but often they are not aware beyond what their immediate training requires and disposing of flammables was not immediate at the time. Now they know.

[Tom Sontag]

I usually hve a couple paper towels and simply light them inside a galvanized bucket or on the some dirt (outdoors!) when I am finished. The firebug in me likes it this way. Boy, that oil burns hot.

[Zahid Naqvi]

My noviceness (if there is such a word) at woodworking requires further explanation. What is BLO? and what kinds of finishing products should I be carefull about? I mostly stick to water based paints and finishes (so far) because of ease of application, but I do have paint thinner and lacquer thinner type stuff in my garage.
If there is a risk of combustion, as stated above, the best option would be to just burn the stuff instead of drying.

Zahid

[Greg Wandless]

Jeff,

I flatten mine out and drap them over the edge of a metal waste can for a couple of days, then out with the trash ASAP.

Greg

[Dave Anderson NH]

As others have stated, regular solvents like paint thinner, naptha, turpentine, and lacquer thinner are flammable but not a problem for spontaneous combustion. They will burn and care should be exercised with them around open flames, and in any situation where you could get a concentration of vapors high enough to have a spark set them off in the air.

What we are concerned with is the insidious effect of drying oils like BLO (Boiled Linseed Oil), walnut oil, tung oil, Danish Oil, and a few other less common oil based products. These oxidize in contact with the air, and when they are crumpled up in piles or in balls, they begin to generate heat from the oxidation. This heat builds rapidly until it reaches a point where the oils and the paper or cloth they are carried in reach their ignition temperature. Depending on the amount of oil in the cloths or papers and environmental conditions spontaneous ignition can occur anywhere from as little as 15 minutes to as much as 12 hours later. If you want to prove this, take some rags or papers and wet them with one of the drying oils and crumple them up in a metal pail outdoors. Do this well away from flammables and your house. Then jsut sit down in a chair with a book and wait. You will be amazed.

You must have seen the picture I posted earlier in this thread. My friend was lucky not to lose hishouse which was 75 feet from the shop. Don't worry though, he came out all right in the end. If you look at the top of the photo carefully, 65 of his friends got together 2 months later and build him a new shop in one very long and tiring weekend.

[Jim Young]

Here is my answer. I just hang the rag on my jointer handle till it dries. This wouldn't work if you use lots of rags.

[Chris Padilla]

I find it curious that no one attempts to WASH or CLEAN their soiled wiping rags. I just toss mine in the washer machine.

[Jim Becker]

I find it curious that no one attempts to WASH or CLEAN their soiled wiping rags. I just toss mine in the washer machine.

In my case, it's because I use disposable towels, not cloth. They are thick, absorbent and inexpensive. While we don't use many paper products in the house as a rule, for this purpose, I prefer the paper. (I buy the Scotts "rags in a box" in the blue and yellow box from the big box store)

But to your point, even if you are going to wash them, unless you thrown them in and put the wash cycle on immediately, you can still have the fire hazard.

[Jim Young]

I thought the paper towels would leave lint or whatever that stuff is. I'll have to try them if they work. If they work for oil then they should work for other finishes.

[Howard Acheson]

You can spread oily rags out inside your shop. The key is to allow air to freely get to them. I have a clothesline and I just drape them over the line until they dry. Once they are dry, they can be discarded in the normal trash.

The reason I don't like using water filled cans or similar water solutions is twofold. One, when you remove the oily rag from the water, it is still capable of combusting when the water dries out. In other words, soaking the rag in water prevented the air from allowing the oil to cure. Take it out of the water and the air allows the oil in the rag to begin to cure which generates the heat. Second, the water you soaked the rags in is now considered a hazardous chemical waste and should not be discarded just by throwing it out.

Seems to me that the best option is to just hang them up either outside or inside.

[Jim Becker]

I thought the paper towels would leave lint or whatever that stuff is. I'll have to try them if they work. If they work for oil then they should work for other finishes.

The towels I'm using (as described above) are lint-free and quite absorbant. I use them for both flat-work and for finishing turnings on the lathe.

[Jeff Skory]

You can spread oily rags out inside your shop. The key is to allow air to freely get to them. I have a clothesline and I just drape them over the line until they dry. Once they are dry, they can be discarded in the normal trash.

The reason I don't like using water filled cans or similar water solutions is twofold. One, when you remove the oily rag from the water, it is still capable of combusting when the water dries out. In other words, soaking the rag in water prevented the air from allowing the oil to cure. Take it out of the water and the air allows the oil in the rag to begin to cure which generates the heat. Second, the water you soaked the rags in is now considered a hazardous chemical waste and should not be discarded just by throwing it out.

Seems to me that the best option is to just hang them up either outside or inside.

Howard,

Makes sense. But doesn't it make you a little nervous having those rags IN your workshop? Any idea on whether rags or paper towels present more of a danger? And how long does it take to dry out?

I would think that the BLO that has soaked into the wood would pose almost as much of a danger but apparently not. Maybe I can find some more indepth info at the manufacturer's site. I'll have to look later tonight.