Reasons to be careful

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Nice article.

How OSHA currently judges with a paper clip. :)

"So is the sawdust in my facility a hazard? It depends, Scott says. The really dangerous stuff is so-called ?wood flour? ? fine particles

500 microns or smaller."

It appears to be a very small chance.

However as far as I am concerned the breathing of the "wood flour" is my concern, so I will be paying attention, to this for my sake.

Steel wool catches fire easily, just so as you are aware of it. I like to bet that I can set steel on fire. ;) Haven't lost yet.

Reply to
OFWW
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I hope every one also noted the comments about the static electricity that can build up in plastic pipes in your dust collection system. They must be grounded to dissipate this charge.

Also while the article is about wood dust, the dust of other organic material can be equally explosive.

Bottom line keep things clean and avoid excessive dust.

Reply to
Keith Nuttle

Setting steel wool on fire is an old boy scout trick for starting camp fires, since two D cells are sufficient, and flashlights often had D cells in them.

Mythbusters did a test with coffee creamer and a flare. The creamer wouldn't catch fire until it was blown (as in with wind) into the air. When it got to the right mix it nearly exploded. Wood flour (and even wheat flour) is the same thing; as a pile on the ground it's safe but as a cloud in the air it's highly flammable.

Reply to
DJ Delorie

Broken record: the concentration would have to be so high that you couldn't see across the room, let alone breathe.

I think Darwinism would do us all a favor and explode the shop of any woodworker who would let that kind of "cloud" be produced is his shop. Lord know, I wouldn't want to see any of his work if he's that reckless.

I can't even imagine a normal woodworking scenario in which that high a concentration of wood dust could occur.

Reply to
-MIKE-

And again, I have yet to see or hear of a credible documented case of a dust collector pipe explosion from static charge. I'm still waiting. It's the Loc Ness Monster of woodworking folklore. :-)

Reply to
-MIKE-

The linked report had a suspect cause: wood flour collected in hidden spaces, something else went FOOM (like a small contained bit of wood flour) and that blew all the other wood flour up into the air in a contained space, starting a chain reaction.

Granted, this is rare in a home shop, but the focus of the report was a commercial building that actually exploded, so it's not *impossible*.

Reply to
DJ Delorie

Keith Nuttle wrote in news:naj7q0$19ad$ snipped-for-privacy@gioia.aioe.org:

If you notice static from your DC system, by all means ground it. It's not for safety per se, but just to keep you from getting an annoying shock. One of the normal human reactions when you get a shock is to move rapidly away from it, which could cause you to hit something.

I had to ground the discharge chute (a piece of downspout extender) on my planer because of the annoying shocks. That's the only reason I bothered.

Puckdropper

Reply to
Puckdropper

Right. But there's a boatload of things that aren't *impossible* about over I'm not about to lose any sleep. The perfect storm can always occur when the odds are stretched far enough. The fact that something happened once, or even twice does not justify rampant paranoia about it.

Of course, I forget I'm living in the age of the tinfoil hat society where a good portion of society thinks we're hiding aliens at area 51 and the moon landing was filmed on a Hollywood sound stage.

Reply to
-MIKE-

Thank you, voice of common sense. I believe that's the *actual* reason for grounding a dust collector system. Unfortunately it seemingly got hijacked by the oak rust society and now the common but false believe is that's it's done to prevent "explosions."

Another reason to use metal ducting.

Reply to
-MIKE-

BOY HOWDY!

Reply to
OFWW

Well Mike, when you used the magic word imagine, I did.

In a vacuum strange things happen, given a spark, and a whoosh of dust already suspended in the pipe (your cloud) and I can see things happen that wouldn't happen in a positive pressurized pipe.

Yet the bottom line is all the home and small shops around and no real stories other than health hazards. If there were fires then the insurance industry would be all over it in a minute, raising prices as if you had a bad dawg in the back yard.

Reply to
OFWW

You've got it wrong, the aliens are holding us hostage at area 51. That is why our taxes are so high.

Reply to
OFWW

.

Broken record or not. There is a very low probability of people being stuck by lightning, but they are. There is a very low probability of people being struck by a meteorite but there is a recent story in the news about that happening.

There is a very low probability of a person being killed by a falling tree, but there are people who are cutting down their trees every day so they do not fall on them and kill them.

Low probability means exactly that, it can happen but infrequently.

Remember Murphy's law. Why tempt Murphy.

Reply to
Keith Nuttle

On 02/24/2016 12:03 AM, DJ Delorie wrote: ...

But what caused the FOOM (that is, what was the ignition source)???

Reply to
dpb

On 02/24/2016 1:38 AM, OFWW wrote: ...

If it were a vacuum, there'd be no oxygen, hence no combustion.

Even in the highest CFM DC systems the air pressure is only a minimal amount below atmospheric pressure; yes it's a big "vacuum" cleaner, but there's really not a lot of vacuum, it's just slightly lower pressure air moving at a pretty high velocity. Hence, there's not going to be any strange things happening owing to anything other than that there is a concentration of dust created and given a large enough ignition source, one could potentially cause a boom. But, static electricity from PVC for at least home-shop-sized duct work simply doesn't have sufficient energy to do so. Metal hitting an iron impeller, _maybe_, but still unlikely. More likely would be an overheated bearing or another open ignition source like a steaming tube or the like that gets away but getting it into the necessary location is the trick there...

Reply to
dpb

The point is, there's a low probability in everything. If you want to worry about everything that is technically "possible" happening to you, go for it. Enjoy that life.

That's the kind of severely flawed logic that inhabits the brains of people who will never fly on an airplane but have no problem driving on the interstate, even though the chances of injury or death are almost unbelievably, exponentially higher when driving a car.

If people want to live in fear of everything that "might" or "could" happen to them, well... let's just say they make lots of pills for that condition. :-)

Reply to
-MIKE-

You are more likely to cut yourself on a TS if you don't own a SS. ;~)

Reply to
Leon

There is a difference between worrying about the probabilities of accident, and taking steps to avoid a potential for an accident. You do not spend a lot of money installing things to prevent an 1 in a million probability of accident. However you don't ignore the possibility that it can happen. Sort of like walk under a ladder, the probability of something falling off of the ladder is remote, it is just good practice not to get in the habit of doing it.

There are other places where this applies. You buy home owners insurance even though there is a small probability that your house will be damaged or broken into. You make sure there are not children in the area where you are mowing even thought the probability you will hit something that will fly our and hit a child. Most people modify there behavior or make purchases based on low probability events.

Reply to
Keith Nuttle

And yet there are really no reasonable steps to take to keep saw dust from exploding because of static electricity in your DC, which is what this thread is about.

Reply to
Leon

Everything you mentioned is covered by insurance because the probability or likelihood of them happening is actually fairly high, in the context of this conversation.

When's the last time you saw insurance companies offering personal lightning/meteor strike policies. Heck, I should do that. It would the most lucrative profitable business ever.

Reply to
-MIKE-

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