Thread: Close Call Fire!

Cutting up the cedar antiques Sam . Lets see a leg and piece of wood.

Yeah sparks and dust extractors don't mix well.
Interesting that it happened as easily as hitting metal with the saw blade. Did it kill the saw blade?

I know a guy who bought a dust extraction system from a factory that had closed down. He had to remove it and was instructed not to use an angle grinder. What does he do. He uses an angle grinder. Started a fire and burnt the factory down. And then got sued.

I remembered the above story and still pushed my luck with my cyclone. Never again will I do that.
I had my steel cyclone in the workshop lying down not connected to any pipes working on it and a spark from my welding got inside. The cyclone had accumulated pockets of sawdust in unseen corners inside that caught the spark and started smoking. I couldn't put it out for a while as I couldn't get to it. I did manage to put it out but went through a bit of panic attack thinking I may have to drag the cyclone out and way from the shed.
Its a bit of a big cyclone to be dragging about.

IMG_4023.jpg

Rob.

I was intrigued to watch a video of some logs being milled on-site where they fell, and to see nails inside the timber. Presumably, when the tree was younger someone used the trunk as a fence post or similar and as the tree grew the nail became embedded.

Now that I can understand, but not how that screw was in your piece.

Originally Posted by auscab

Cutting up the cedar antiques Sam

Haha!, God no!, It was too modern.

Originally Posted by auscab

Did it kill the saw blade?

Amazingly it didn't seem to have an affect on the blade, I checked it thoroughly, I put it down to my feed rate being pretty slow at the time and I backed the wood straight back out soon as I heard it hit.

I've milled all the wood now but here's some of top

IMG_0115.jpg

And these are the legs....

IMG_0116.jpg

Is it cedar?. It looks too dark to be Tassy oak?.

Excellent observation on your part. It does not take much at times. I have a self imposed rule in my shed - no hot work! I do all hot work outside in the open air.

Google "combustible wood dust explosions / fire" - there are numerous examples very similar to the above events.

One other thing to be very mindful of is spray booth over spray build up if you use nitro cellulose finishes.

Originally Posted by EagerBeaver71

And these are the legs....

IMG_0116.jpg

Sorry Rob, this wasn't off the table legs, only the other wood is from the table.

I had a similar close call some years ago with a small belt/disc sander. I recall posting about it. Had a bit of metal to grind. I did think about sparks so first took off the hose from the shop vac and got started. Burning smell then whisp of smoke from the sander so had to heave it out into the back yard. Took off the belt guard and found smoldering ember in the caked on dust. Makes you think of all the other potential fire sources in the shed so I got an extinguisher after that and am more careful about grinding. Sander survived all right and I got a few more years out of it.
Regards
John

Originally Posted by orraloon

I got an extinguisher after that and am more careful about grinding.

Hi John,

I got an extinguisher aswell along with a medical box which has everything in it from plasters to tweeser's, fortunately I've never had to use any of it apart from the tweesers and a couple of plasters .

Tweesers are always handy around woodworking.
Regards
John

Originally Posted by EagerBeaver71

I've milled all the wood now but here's some of top

IMG_0115.jpg



Is it cedar?. It looks too dark to be Tassy oak?.

That looks to be Mahogany.

Originally Posted by auscab

That looks to be Mahogany.

Bloody hell really Rob?, I don't think the legs were Mahogany, just the aprons and top. It wasn't that big...

Maybe check this out
Fire in Flexy

Originally Posted by BobL

Maybe check this out
Fire in Flexy

Well mine don't seem so bad after looking at that! Holly Cra@p!

Another task & risk many wood workers tend to ignore is cleaning their table saw and all wood working machines regularly!

Trapped thin rips rubbing against a blade doing 5000 + rpm can generate a fire.

Just open the cabinet on any machine, particularly table and band saws, in any wood workers shed.

Over the years I've seen many wood working machines that are so full of crap that any potential fire hazard has a quite high probability of causing a fire & has plenty of fuel to sustain that fire. Saw dust & air being a relatively good "insulator" can preserve the heat from a spark for quite a long period, enough to promote and sustain ignition.

Given the relatively poor air circulation from dust collection systems in the machines cabinet most likely means it is doing enough to encourage a fire from a spark.

Remember the old fire / combustion hazard triangle - fuel - oxygen - heat! Fire triangle - Wikipedia we can control two of the three, fuel & heat.

The best actions as safety controls is to eliminate, or minimize. Eliminate by excluding "hot work", minimize by checking for possible ignition hazards (as in this example metal in wood) regular maintenance & cleaning to remove one element of the fire triangle - the fuel, and hopefully the second - a source of heat. Removing the oxygen isn't at all practical or healthy for the wood worker! At times that regular cleaning could be mean doing it several times a day!

Trapped sawdust is probably something like 50/50 by volume wood & air aka oxygen! Simply add heat, oh and we have a means to sustain that heat for long(er) periods than a spark in open air.

As an after thought - in Cairns near the old Brewery was the old Cairns Timber Limited (CTL) saw mills and mangrove swamps to the south to the Sugar Terminal. Guess where all the saw dust went! That area is now developed into commercial retail etc. Right up until the early 1990's there would be fires that would "surface" from the underground slow combustion of the sawdust. The Fire Brigade could never totally "put out" the fires. Some suspect that they may still be there! Trove cairns fire.

As kids we were told to never visit or play in that area, due to the very high risk of subterranean fires, and "breaking through the surface crust." There would always be frequent wisps of smoke in that area.

Originally Posted by auscab

Cutting up the cedar antiques Sam . Lets see a leg and piece of wood.

Yeah sparks and dust extractors don't mix well.
Interesting that it happened as easily as hitting metal with the saw blade. Did it kill the saw blade?

I know a guy who bought a dust extraction system from a factory that had closed down. He had to remove it and was instructed not to use an angle grinder. What does he do. He uses an angle grinder. Started a fire and burnt the factory down. And then got sued.

I remembered the above story and still pushed my luck with my cyclone. Never again will I do that.
I had my steel cyclone in the workshop lying down not connected to any pipes working on it and a spark from my welding got inside. The cyclone had accumulated pockets of sawdust in unseen corners inside that caught the spark and started smoking. I couldn't put it out for a while as I couldn't get to it. I did manage to put it out but went through a bit of panic attack thinking I may have to drag the cyclone out and way from the shed.
Its a bit of a big cyclone to be dragging about.

IMG_4023.jpg

Rob.

Hey Rob, quick question;

are you just slinging this off your portal frames with the chain hoists? Or some kind of additional gantry?

Thanks,
Tom


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