Danger of oily rags

[Doug Hobkirk]

Is one rag dangerous or is it when several are thrown together? I don't want to burn my house down!

I am doing some varied refinishing, and I frequently leave rags that have been soaked (with wipe-on poly or shellac or oil stain or paint) that I want to reuse in 4-8 hours for the second or third coat. I spread the rag out but leave it in my garage during this time. If I have more than one rag in active use, I keep them apart. After I'm done, I spread the rag out outside to dry before I trash it.

Am I being safe? Should I seal the rags individually in an air-tight container (in Tupperware? Ziploc bag?) during those 4-8 hour intervals?

[Jim Knishka]

NO! One rag is enough -it's about lack of circulation. Many years ago when building our first house, we were finishing our own woodwork we stained late one night and were tired, and came back the next morning to find the icecream bucket of rags smoldering. Another hour or so we would have lost the house. This was less eight hours. Drap them to dry, or put them in water and write them off.

[Neal Clayton]

yeah, don't contain them, that's what causes it.

when i was in college working at a hotel a waitress got burned that way, picked up a bundle of napkins in the kitchen and by the time she got to the washing machine they caught fire in her hands.

drape them separately over something and they'll be fine, do not stack them or otherwise enclose them in anything.

[jerry nazard]

My first, and hopefully last, experience with this was 30 years ago. I was using a felt chalkboard eraser to apply Watco danish oil. Walked into the shop one morning and reached for the eraser - it was almost smoldering hot! Lesson learned and not forgotten.

Best!

-Jerry

[Jason Roehl]

No need to be afraid of anything with 'oil' in the name, though. What you need to be careful of are products that contain oils that oxidize when they cure--BLO, tung oil, danish oil, etc. Mineral spirit-based stains won't do it (like Minwax), motor oil won't, veggie oil won't, mineral oil won't, because none of those cure or oxidize.

And, actually, the "approved" method of storage until disposal is to put them in a metal can filled with water and put a (metal) lid on it. If you drape the rags over something to dry, do that outside. In the shop, someone else could come in, cause a draft, and that rag may end up on the floor in a heap--then you're out a shop.

[Per Swenson]

Related Anecdote,

And remember folks ignition is a funny thing.

I don't mean funny, ha-ha, I mean funny as you never know.

A Harry the homeowner neighbor fella, and good friend besides,

decided to polyurethane his hardwood floors. Rented a floor sander,

Did the job and applied the poly.

The poly never dried. It was late winter, cold wet damp and crappy.

The floor was like one of those glue traps for mice.

Mind you, it was no bigger then 12 x 16.

He rerented the floor sander, it being only 12 x16, the finish came up

and in the bag in 10 minutes. 10 minutes. At 11 minutes I smelled something funny. Asked him to take that bag outside quickly.

Speakin of funny, it was the look he gave me, the you know ,

whatsa freakin mhatta wuth you? tough guy look, (spelling for NJ accent)

That was when the bag ignited.

It smoldered and burned outside in a snowbank with light flurries

for close to 12 hours.

Per

[Lee Koepke]

good story Per :eek:

I use a piece of closetmaid shelving to spread my rags out on. before i leave the shop, i pick up the shelf and put it outside.

Just like any other safety feature in the shop, common sense and good habits go a long way.

I hang ALL my rags on that shelf regardless of what I used, thus maintining the habit, and limits the one time I may forget to properly store my BLO rag ...

[Cliff Rohrabacher]

No need to be afraid of anything with 'oil' in the name,

Perzakly so.


What you need to be careful of are products that contain oils that oxidize when they cure--BLO, tung oil, danish oil, etc.

Perzakly so.

My method is the most scientifically well engineered solution known to man.

I invoke a highly sophisticated application of the earth's gravitational field and the atmosphere to randomly isolate each such rag from any other while utilizing the molecular power of Brownian motion in gases that occur naturally to obtain convection dispersing the heat.


I toss 'em on the floor with the saw dust and scraps and junk. Then days or weeks later when I'm sick of tripping over the accumulated junk I get a steel rake and a broom and a snow shovel and put all that crap in a heavy duty garbage bag and set it on the curb (OK, I don't really have a curb) for the townies who come by and for reasons I can't understand they seem to want the stuff and collect it.

[Mike Monroe]

Firefighter Mike here. Few years back had a local guy burn down his garage because he didn't believe the warnings on the Watco Danish Oil can. It was a detached garage and we were able to save the house, though it was touch and go there for a little bit. The guy had quite a few combustibles in the garage; kerosene, petrol, ammo, gun powder, etc…

Bottom line, don’t risk a fire. Deal with oily rags appropriately every time.

[Jesse Cloud]

I've got a 25 cent solution for ya...

I tie a piece of string about 3 feet long to one of the outdoor utility pipes (doesn't matter what, just so it will hold the string) and the other end to the trash can about three feet away. Use clothespins to attach oily rags, one per pin. They dry in a few hours and then I toss the rags into the trash and untie the trash can end of the line.

For rags that will be reused in a few hours, I put them in a special air tight container, aka old glass jar with a lid. They don't dry out and are ready to go for the next use. One hint, don't use a jar that still smells. I once had to redo a project that smelled of pickles.:p:o

[Rick Levine]

This is why I invested in one of these:
(A safe, relatively inexpensive way to store the rags until I can dispose of them safely)

[Mike Henderson]

Let me point out that there's two kinds of oil - drying oil and non-drying oil. The dangerous stuff is the drying oil because it generates heat when drying.

The red containers don't prevent oily rags from catching fire (unless you fill it with water or it's air tight), they only contain the fire. They need to be emptied often (before the rags catch fire). It's much safer (in my opinion) to dry the rags flat somewhere.

Mike

[Howard Acheson]

The most dangerous rag is one that has been wetted with boiled linseed oil or a finish containing a high percentage of linseed oil. These finishes are the oil/varnish finishes like Danish Oil, Tung Oil Finishes or a home brew oil/varnish. These rags should be spread out and allowed to dry. Once dry they are no longer dangerous and can be discarded in normal trash. It's the slow polymerization of linseed oil that leads to heat being produced over a long period. Fast evaporating solvent/thinners are not dangerous.

Rags with oil based varnish or poly varnish are not very dangerous as they do not produce much heat as the finish dries. Rags that have thinners like mineral spirits, naphtha, acetone, lacquer thinner, etc are not dangerous. Nor are rags that contain lacquer, shellac, or waterborne finishes.

But, let me point out, that rags with finishes on them should not be stored for more than an hour or so. Oil based and waterborne finishes cure by oxidation or the interaction of the finish with oxygen. Once exposed to oxygen the finish starts curing and will continue--but at a reduced rate--even if stored in a seal jar or package. It's best to use a fresh applier for each coat if you can't get back within an hour. I use non-embossed shop paper towels for applying wipe on finishes so it cheap to just discard them after each use.

[Tom Henderson2]

Is one rag dangerous or is it when several are thrown together? I don't want to burn my house down!

I am doing some varied refinishing, and I frequently leave rags that have been soaked (with wipe-on poly or shellac or oil stain or paint) that I want to reuse in 4-8 hours for the second or third coat. I spread the rag out but leave it in my garage during this time. If I have more than one rag in active use, I keep them apart. After I'm done, I spread the rag out outside to dry before I trash it.

Am I being safe? Should I seal the rags individually in an air-tight container (in Tupperware? Ziploc bag?) during those 4-8 hour intervals?

There have been a lot of responses, and a lot of techniques shared, but I don't think anybody addressed your specific question about how you are handling it.

It sounds to me that you are spreading the rags out, allowing good air circulation, and keeping the rags separate. That sounds like safe practice to me.

I have typically draped the rag over the lip of the trash can. They aren't touching anything but the barrel and dry out pretty quickly.

The risk, as I underestand it, is when there isn't enough air circulation, as when rags are wadded up, or worse, many rags are wadded up in the same container. Heat is generated, and combustion can occur.

-TH

[Eric DeSilva]

I've got a basement shop. I posted a similar thread a few months ago, and decided to take things seriously. Now, whenever I'm done with a finish rag, I step outside into the concrete stairwell, and use one of a little spring clamp to clip it to the metal rail. When I do that, I pick up the rag I left out there the last time and pitch it...

[Michael Faurot]

What I've been doing, when applying finishes and anything else that I think is combustible--is to use disposable rags. The rags are used once and then put in a container of water until they can be disposed of permanently.

Mostly I use those blue shop rags. If the project is small, I'll cut up a single blue shop rag into four pieces. If the project requires the touch of something like a cotton tee shirt, I'll cut up pieces of the shirt, use those pieces and then dispose of them in the contrainer of water. I also use latex gloves when applying a number of finishes, and those get used once and then disposed of in the container of water.

Blue shop rags, tee shirts[1] and latex gloves are cheap. I would rather use them once and throw them away than try and recycle them and have them catch fire and destroy something.

[1]: Thrift stores are great places to find inexpensive tee shirts to use as rags.

[Michael Schwartz]

My policy is that oily rags are removed from the shop and placed in a metal trash can that is stored outside within 15 minuets of use. Then when they are dry they are disposed of with regular trash.

[Cliff Polubinsky]

A question about keeping rags in water until they're thrown out. Wouldn't that pass the risk on to your trash collector? The finish won't cure under water so once the rag gets tossed it continues the curing process. Except now it's bunched up where heat can't dissipate and is more likely to catch fire. If the collection truck isn't emptied in time, it could ignite in the truck. It would appear if you store the rags in water for safety, the best practice would then be to dry them out flat so they're no longer a threat before you pitch them.

Cliff

[Doug Shepard]

I just step outside the GaShop and thread them thru the cyclone fencing. After a few days when they're good and dry, they get tossed into the trash.

[Ted Jay]

I throw them in the burn barrel, where they are free to ignite...

Ted

[Rich Engelhardt]

Never mind..

[Wayne Cannon]

Don't ignore a single rag for even a minute.

I was wiping up the excess oil from my deck, tossed a rag (one rag) loosely to the side for no more than a minute while I moved my gear only to find it was already smoking and had a number of charred holes when I picked it up again, and there was already light charring on the deck wood. I'm sure being outdoors in the summer sun accelerated the combustion, but it gave me a new respect for just how quickly combustion can begin.

[John Keeton]

I like Doug's idea with the cyclone fence - the side benefit could be an ongoing art project using multicolored shop rags!

For lack of a cyclone fence, I use the edge of the trash can method which seems to work well. Usually, putting on a coat of finish is the last thing I do before I leave the shop, so the fumes aren't an issue. It is dry by the next day.

[Wade Lippman]

I typically wear plastic gloves and stick the rag in one turned inside out so it won't dry inbetween coats. Been doing it for years and nothing has been even slightly warm. Perhaps it is because I don't give them any air exposure.

When I am done I toss them out the back door and clean them up once a week. Fortunately my wife never looks back there.

[Dan Lautner]

Get a large metal bucket filled with water and submerge any rags. I have tried everything and this is the only way I feel safe at night. I have seen too many smoldering rags to take any chances.

Dan

[Doug Hobkirk]

Thanks everyone!

I think Wade's Inside-Out-Rubber-Glove-Containment & Doug's Cyclone Fence & Ted's Burn Barrel take the cake. Although I don't have a cyclone fence or a burn barrel. I might start a burn barrel. I won't put up a cyclone fence!

It's sobering to find that my planned major finish from David Marks (or is it Sam Maloof?) of Tung Oil, Boiled Linseed Oil, and Poly contains 2 of the main culprits for dangerous rags. I think this might be sufficient reason to move toward shellac solutions.

[Will Blick]

Wayne, that is quite amazing..... I bet these rags in hot dry garages are really an ideal place for FAST combustion.

It seems the water solution is risky, as eventually the water will dry, and you might forget about it....

[Cody Colston]

This thread reminds me of a short story from a book I read in second grade. There was an axe stuck in the ceiling and eventually the whole family was agonizing over the fact that the axe could fall on someone and kill them. The solution, of course, was to take the axe down.

I believe its been well established here that drying oils can spontaneously combust and if you didn't now that, it's also on the label on the container. So, wash them, lay them on the floor, drape them over a trash can, thread them in a cyclone fence, throw in the burn barrel (my favorite) or toss them out the back door but don't wring your hands and fret over how to treat them and don't spend too much time worrying about the garbage truck, either. sheesh.

FWIW, I throw mine on top of my burn pile in a gully about 100 yards from the house. I've intentionally wadded a bunch of BLO soaked rags together and thrown them on there...in 100 degree Texas heat no less.

I'm still waiting for self-combustion to occur. :rolleyes:

[Glen Gunderson]

My parents had a fire as a result of a few oily rags from oiling pieces for a cedar ceiling. Luckily they caught it and were able to put it out with a garden hose before the fire department got there (much of the house would have probably been ruined from water damage if they used their hoses), but there was still about $50,000-$60,000 in total damage and several months of living in a construction zone afterwards while it was restored. It was only a few rags that my dad didn't dispose of properly and they almost lost their house because of it.

Sure it's a 1 in a million thing, but it can certainly happen, so be careful.

[Dan Lautner]

"Sure it's a 1 in a million thing, but it can certainly happen, so be careful."

If you use certain types of finish like Penofin it is about a 1 in 1 chance of self combustion.

[Norm St.Onge]

My floor refinisher burned down my 8 yard demolition dumpster by throwing his rags and bags of sawdust in it. Living out here in the woods no one so it burn, it turned a heaping overflow pile of construction debris into 12 inches of smoldering ashes over night. It also twisted the dumpster so that the hauler had to beat the hoist pins with a 3lb hammer to align them enough to pull it onto the truck.

-Norm

[Anthony Whitesell]

I use a tomato hoop and hang them with wooden clothes pins outside and away from the house. Quick, cheap, easy, and anywhere but in the shop.

[glenn bradley]

I spent $10 on a lidded galvanized bucket. When I use finishes that can combust while curing, I keep a couple inches of water in the bucket and throw the rags in as they are used. Between sessions, I lid the bucket. When I'm through I lay them out to dry and then toss them. One rag or a dozen, I do the same thing. I find safety habits that are automatic easier on my tiny brain.

[Howard Acheson]

A question about keeping rags in water until they're thrown out. Wouldn't that pass the risk on to your trash collector? The finish won't cure under water so once the rag gets tossed it continues the curing process. Except now it's bunched up where heat can't dissipate and is more likely to catch fire. If the collection truck isn't emptied in time, it could ignite in the truck. It would appear if you store the rags in water for safety, the best practice would then be to dry them out flat so they're no longer a threat before you pitch them.

Cliff

You are correct. In additioin, how you dispose of the water becomes an issue. Technically, the water is now contaminated as many municipalities require it be treated as a hazardous waste.

It's so much easier just to hang the towels up on a clothes line of over a bush and let it dry.

[Prashun Patel]

Not sure if someone already mentioned this, but you probably SHOULDN'T leave your rag out in the open if you're planning to reuse them. Apart from the fact that it'll partially dry and impede yr ability to rub nicely on the next use, it'll begin the oxidation process which is what makes it flammable.

It's actually best to store the rag in a little bit of solvent at the bottom of a sealed jar. This minimizes the contact w oxygen and keeps the rag from drying.

[Doug Shepard]

While we're on the subject, I'm thinking epoxy might fall into these same warnings too? That gets pretty darn hot when initially starting to gel. It's hot enough to melt holes through plastic containers. I'm thinking under the right circumstances it might be possible to ignite something dry if tossed into the trash.

[Jeff Mohr]

I also use latex gloves when applying a number of finishes, and those get used once and then disposed of in the container of water.



I typically wear plastic gloves and stick the rag in one turned inside out so it won't dry inbetween coats. Been doing it for years and nothing has been even slightly warm. Perhaps it is because I don't give them any air exposure.


Makes me wonder....

Is there any danger with latex gloves that have the stuff on them? I take off my gloves inside out, should I then turn them rightside out and let them dry?