BLO fire danger.

[Wooden Affairs]

I November we had a large fire that destroyed tens of thousands of dollars of wood (Texas Ebony). This has got me very cautious. I have had two encounters with BLO that have me a little jumpy. The first resulted in a small fire in just a few moments. We made a large oak bench used BLO on it but there were problems with the finish so it was sanded off with a large belt sander. We stopped to eat lunch and before we could finish we could smell the sander burning. The bag was just a pile of ash. It was in the middle of the floor so there was minimal damage. The second was a small rag in a bowl. We were delivering another bench and were going to touch it up at the store. We had a small rag in a bowl it was left in the seat while we unloaded the bench (400 lbs). it was not too hot outside but the rag was smoking hot. This worries me about spills in sawdust. I am sure the catalyst was heat for the one but I am not sure why the sander burned. It is something to keep in mind.

 

[islandturner]

The second was a small rag in a bowl. We were delivering another bench and were going to touch it up at the store. We had a small rag in a bowl it was left in the seat while we unloaded the bench (400 lbs). it was not too hot outside but the rag was smoking hot.

Do you think that this was due to spontaneous combustion? I often have a pile of paper toweling used with BLO and CA from finishing on the lathe. Had never considered this possibility...

Thanks for the heads up....

 

[ElMostro]

When I use BLO for anything I normally keep a large tin can (old coffee can) 1/3 filled with water next to where I am working, once I am done using the rags or paper towels they go into the water can...just in case. If the weather is not bad and the shop door is open then I lay the rags outside over something to dry them out and before I put them in the trash I wrap them up in foil.

 

[JimB]

When I use BLO for anything I normally keep a large tin can (old coffee can) 1/3 filled with water next to where I am working, once I am done using the rags or paper towels they go into the water can...just in case. If the weather is not bad and the shop door is open then I lay the rags outside over something to dry them out and before I put them in the trash I wrap them up in foil.

Same here. I keep a bucket with water in it. Anything I use for finishing goes in there. If it touches CA, BLO, shellac, tung oil etc etc etc it goes straight into the water. This includes sandpaper as well as rags, paper towels and gloves. My shop is in the basement so I am not taking any chances.

 

[Wooden Affairs]

I have been told that old rags need to be kept in a can away from other things. I clean up every time I use BLO. I am worried about spills in sawdust.

 

[jbswearingen]

Do you think that this was due to spontaneous combustion? I often have a pile of paper toweling used with BLO and CA from finishing on the lathe. Had never considered this possibility...

Thanks for the heads up....

Yes. As BLO cures, it undergoes an exothermic reaction--it gives off heat. When a rag or paper towel is soaked in it, and then balled up, and THEN insulated (like being stuffed in the trash), the heat can build up enough to cause combustion--the wood/paper/cotton catches fire.

ALWAYS either lay out the rag/paper towel flat to cure BEFORE discarding, or soak in water before discarding.

 

[Rangertrek]

+3 on the can of water near the work bench. I toss all my CA paper towel strips in the water. This goes for all rags, towels, etc. with any residue of a finish.

 

[Monty]

BLO will spontaneously ignite, just ask Curtis.

 

[Justturnin]

I have never experienced this, thank goodness, but I have read about and am awareof it. When I use BLO I actually take my rags outside and place them in the middle of a good size bare dirt spot in the backyard. That way if they do decide to burn they burn dirt or dry out, whichever comes first.

 

[Chris Bar]

Scared to death of spontaneous combustion so any rag with oil or wax or whatever is laid open on the floor, then taken outdoors to the burn pile as I leave the basement shop. I do have metal filing drawers in the garage some of which that have a film of motor oil leaked from cans etc. Since there are no rags or paper, only the cans, am I entertaining a false sense of safety.
Thanks for reminder on BLO.

Have a Delta dust collector with plastic bag that catches the sawdust. Just wish there was an aftermarket metal can that could be used instead of the plastic so that removal to empty would be easier, which is now a PITA.

 

[sbell111]

Anyone who doesn't have a fireproof trash can in their shop should get one.

 

[MesquiteMan]

Motor oil will not spontaneously combust, only drying oils. This includes BLO, real tung oil, and any other oil that dries or polymerizes. This also includes oil based stains.

I have a nice black spot on the floor of my shop with a burned leg of my work bench from spontaneous combustion. I had used some danish oil on a bowl one evening and before I went to bed, I laid the oiled paper towels out on the concrete floor in one layer to dry. The next morning, my helper came in and decided to clean up the shop. He tossed the towels in the trash can and we left for the job. We came back a couple of hours later to get something from the shop and when I opened the overhead door, smoke came pouring out of the shop. I was terrified but ran into the "burning building" anyway. In my shop I found the trash can a puddle of melted plastic and the leg of my work bench was black and smoldering.

Also, a number of years ago, my painter burned down a new house by accident by leaving stain soaked rags in a can. Fortunately, it was not one I was building!

 

[Pete275]

I assume from comments on this thread that normal storage of BLO in plastic bottle or the original can is ok and the best practice when using it as a finish is to toss the used towels or rags in a can/bucket of water.

Wayne

 

[Wooden Affairs]

I had a fire proof can. An old military style with the foot lever. It did not fare well in the November fire. It got ran over, twice.

 

[spilperson]

Wow, thanks for the warning!

I always wondered why they warned us about the fire hazards of oily rags...maybe that got started because of BLO?

 

[jbswearingen]

Wow, thanks for the warning!

I always wondered why they warned us about the fire hazards of oily rags...maybe that got started because of BLO?

Not just BLO. Any polymerizing oil presents this hazard.

 

[spilperson]

Not just BLO. Any polymerizing oil presents this hazard.

thanks, I really learned something today! I will be more careful. I usually just toss my used paper towels in a trash can full of shavings, plastic, and other paper...I am sure that would NEVER have been a problem!:bulgy-eyes: