Gun Powder Safety__Fine Particulate Theory__

[WadePatton]

I tried to get some discussion on this back in 2014 (quoted below), but apparently that discussion had run it's course-- or I had bad stinky breath and no one wanted any more of that.   

I have yet to have any thought or discovery displace this notion, and care not to test it.  (At least not right now.)

But a comment by Mad Monk in that thread (below) and my personal recollection of Grain Bin Explosions, allowed me to put "two and two together" in the logical sense for a theory or notion of the actual mechanisms in place in these "mysterious" explosions which have no apparent source of ignition.

Grain-bin explosions happen world-wide, nearly every year since the development of industrial sized grain mills.  The link in my 4-year-old quote is yet good, and of course we can find many more examples.  There are tons of info and accounts on the causes/examples of dust-spark ignition of grain processing and other facilities where ANY sort or dust can be generated from anything of combustible materials.

Risking the "tired old repeat" tag, I'm bringing it up again so that in the very LEAST maybe some others will comment on it and most importantly HELP folks understand how to minimize their exposure to the conditions that can lead to "spontaneous" combustion of our flavor of gunpowder. 

Possibly it goes further and some folks, taking proper precautions, test the theory and we get a controlled example that proves or disproves the theory.

Ultimately it might become "known fact" and some of the  regulations on the handling of gunpowder would be changed, such that distributors would no longer have to follow over-zealous safety regulations. (But that might take a few decades or more)

To the point:

AS we've may have all seen- clean grains of gunpowder defy ignition by electric spark on the youtube*. And thereby folks might erroneously think that powder container explosions cannot be ignited by static.  Yes, clean powder didn't ignite in that video.  But put that same powder in a container and shake it up for a few weeks until some powder residue becomes suspended in the air (as might happen over a few years of our normal use and refilling) and then apply ANY size of spark.  I think it will ignite.  Same as wheat or corn or bean or wood dust.

*I went looking for that video and didn't see it:  It was clean powder on paper, with clearly visible sparks bouncing off/through and no resultant ignition. (Maybe y'all remember it or can find it, or just trust me on that...)

I believe that our containers, with enough use and time and conditions might be accumulating fine particulate dust from vibrations and friction and wear on the screened powder, such that this dust, not gunpowder, could ignite and light the grain powder as well.


SO I clean the residue out my powder flask now and then to prevent an accumulation of fine dust that could possibly, in the right conditions become suspended in air and cause a miniature version of the grain bin/elevator explosion.

I could be all wet, but it doesn't stop me.    If there is/has been better (any) discussion of this subject, I'd be glad to look at it. tnx.

This thing about priming flasks and accidental ignition of the contents was looked at back in the mid-1980s...  But then I found that the film sometimes contained actual powder dust.  So an ignition of the powder dust build up around the spout could act as a fuse into the contents of the powder container.

The end result of all of that work was that it is a good idea to periodically clean the spouts and valves.  No powder film means no fuse effect into the container.

Mad Monk

While i'm not the certified expert MM is, I did quickly associate accidental ignition of BP to the dust/powder of BP and not the granules.  Just like corn/bean/wheat dust is what explodes grain bins-with purely organic dust and a simple spark. 

Most recently http://www.usatoday.com/story/news/nation/2014/09/14/explosion-at-nestle-plant/15648861/

So every time I refill my brass canister, I wipe it clean of residue to help minimize this dust/powder.  I'll now give the spout a little extra cleaning too.  I don't use FFFF for anything these days either. 

Ask the buck in the avatar if FF is "fast enough" for prime.   

[WadePatton]

Apologies for the late edits to the dozen or so viewers, I had some Saturday morning calls and such.  I tried to make it more readable and less rambly.   

I'll leave it as written now but for typos if I find any.  Cheers and mind that breeze. 

[Hungry Horse]

 The title, and the text, keep saying “gun powder” which could be black powder, or any of the many varieties of smokeless powder. I think all you have stated could very well pertain to smokeless powder, but would be highly unlikely with any of the granulation of black powder. Unlike more modern powders, black powder doesn’t degrade with time. Moisture is its only real enemy. Now I must say I know nothing of the modern plastic containers black powder is now marketed in. I know plastics can generate static electricity in the right situation, but whether or not it would ignite black powder dust, I don’t know. I seriously doubt it could happen in the older metal cans. I hunted for years in some very remote country. We hauled out powder in the cans, over roads you could not negotiate in most modern 4WD trucks because of how narrow, and twisted the roads were. We never had any issues, other than our 2F often became 3F during transport.

  Hungry Horse

[WadePatton]

The title, and the text, keep saying “gun powder” which could be black powder, or any of the many varieties of smokeless powder. I think all you have stated could very well pertain to smokeless powder, but would be highly unlikely with any of the granulation of black powder. Unlike more modern powders, black powder doesn’t degrade with time. Moisture is its only real enemy. Now I must say I know nothing of the modern plastic containers black powder is now marketed in. I know plastics can generate static electricity in the right situation, but whether or not it would ignite black powder dust, I don’t know. I seriously doubt it could happen in the older metal cans. I hunted for years in some very remote country. We hauled out powder in the cans, over roads you could not negotiate in most modern 4WD trucks because of how narrow, and twisted the roads were. We never had any issues, other than our 2F often became 3F during transport.

  Hungry Horse

I use the term "gun powder" on this forum to discuss "black powder" because that's our rules and I am making no reference to nitro-cellulose or double-based powders if I don't have to.  I hope this causes no real confusion. Thanks for brining it up.

True dat: the users of modern powders tend not to carry them around in bulk for their use but only in small pre-measured doses kept in relatively tight spaces. And that I think that sort of power has a good bit more coatings and such on it--may degrade slower in same conditions--anyhoo it's mostly outside this forum's "jurisdiction" so again, I mean "BP" when I say "GP".

...other than our 2F often became 3F during transport.

  and this is exactly where I do think the spark ignitable dust, that can become a problem, originates.

[Skychief]

Do any credible accounts of a container of black powder exploding, in the same fashion as grain bins have, exist?

If not, it may be an interesting theoretical exercise, but, only that.

Realize that I ask because I do not know.  Never heard of such.  Don't want my asking to sound "snarky", not meant that way.

Best regards, Skychief.

[smylee grouch]

When it comes to grain bin explosions I have been told that there are three conditions that have to exist before it can happen. All three have to exist at the same time. I don't know if this is the same with black powder or not.

[Hungry Horse]

I think if this was a viable theory, given the cavalier way some people treat black powder, there would be at least a few incidents that would point to this possibility. But, I have not heard of even one, where this scenario was proposed as the cause of an explosion.

  Hungry Horse

[WadePatton]

When it comes to grain bin explosions I have been told that there are three conditions that have to exist before it can happen. All three have to exist at the same time. I don't know if this is the same with black powder or not.

As I understand it, those conditions are "fuel, oxygen, and spark": where the spark can be from an electric motor or switch, air provides the o2, and the fuel is one or many various organic powders, so fine that it suspends in the air.  I suppose there's a particular range of densities or minimum density of the suspension. 

Do any credible accounts of a container of black powder exploding, in the same fashion as grain bins have, exist?

If not, it may be an interesting theoretical exercise, but, only that...

Not sure why it would only be theoretical.  We have incidents in modern times, but yes most of them obviously caught an errant spark. Maybe there is no incident of unexplained ignitions (Save for loading the bore incidents, and I'm dead set against the "compression ignition" theory there. But that's a different ball of yarn and I need to ramble less).

[WadePatton]

I think if this was a viable theory, given the cavalier way some people treat black powder, there would be at least a few incidents that would point to this possibility. But, I have not heard of even one, where this scenario was proposed as the cause of an explosion.

  Hungry Horse

I understand. I'll have to go back and read that other thread. Obviously I was looking to answer a question of unknown ignition, or just a "static spark" theory of ignition.

HAS anyone here seen the video that I've made reference to, where the guy dances sparks all over fresh BP to no effect, and concludes that static cannot ignite BP?

I think that it can, given dust suspension at the time of the static discharge. I really don't doubt static-spark ignition in that condition, but does that condition really ever exist inside our containers. If it does, is it more or less likely to be an issue with any particular shape/size/material container or sort of BP.

Yes I do understand that the pipe-bomb effect is an issue no matter the source of ignition.

[davec2]

Wade,

http://www.ctmuzzleloaders.com/ctml_experiments/sparks/sparks.html

Fist part of this video

[T*O*F]

As I understand it, those conditions are "fuel, oxygen, and spark":

NO....the conditions are fuel, oxygen, and HEAT.  Static electricity doesn't produce enough heat.

There is at least one instance in Australia of a can of BP exploding inside a closed car.  Given the high ambient temps they have there, as well as the car being a solar oven, this is entirely feasible.

An electric motor with bad brushes produces heat because you can smell the ozone being produced.

Lastly stored grain will often spontaneously combust due to heat build-up.

Just food for thought.

[Mad Monk]

When it comes to grain bin explosions I have been told that there are three conditions that have to exist before it can happen. All three have to exist at the same time. I don't know if this is the same with black powder or not.

As I understand it, those conditions are "fuel, oxygen, and spark": where the spark can be from an electric motor or switch, air provides the o2, and the fuel is one or many various organic powders, so fine that it suspends in the air.  I suppose there's a particular range of densities or minimum density of the suspension. 

Do any credible accounts of a container of black powder exploding, in the same fashion as grain bins have, exist?

If not, it may be an interesting theoretical exercise, but, only that...

Not sure why it would only be theoretical.  We have incidents in modern times, but yes most of them obviously caught an errant spark. Maybe there is no incident of unexplained ignitions (Save for loading the bore incidents, and I'm dead set against the "compression ignition" theory there. But that's a different ball of yarn and I need to ramble less).

The loading the bore incidents are easy.  When you fire the gun heat from the powder combustion goes into the metal.  After a series of shots the surfaces of the bore are above the ignition temperature of the powder.  If you don't swab between shots you have hot powder residue on the bore that might ignite the powder being dropped down the bore.  Keep in mind that the powder combustion can produce temperatures as high as 17 or 18 hundred degrees.  This is seen by the glass-like film in the bore with big charges.  Melting of the potassium carbonate, in the bore, takes temperatures up above 1600 degrees.  WAY above the ignition temperature of black powder.

Bill K.

[WadePatton]

YES and YES.

But I'm not talking about lighting whole grains of gunpowder.

I'm talking about lighting gunpowder dust in suspension.  SAME sort of thing that causes great explosions in grain processing facilities.

And I can't get many to -quite- make that leap. Maybe there's absolutely no reason to. 


It was a thought. More on bins/dust:

We have reduced the numbers of explosions here, but this is yet a big deal.

http://siouxcityjournal.com/news/local/grain-bin-explosion-in-hinton-injures-two-scares-residents-blocks/article_000b6aff-8314-5ccc-9196-616461b0a082.html


"Any little spark from anything can set that off," LaCrosse Fire Chief Aaron Rust said. 

excerpt from: http://www.nwitimes.com/news/local/laporte/four-hurt-in-lacrosse-grain-elevator-explosion-fire/article_70548778-27d1-59cd-8cd1-0ec2ff5fec73.html


Whoohoo, got an answer on the density of particulate here: http://www.princeton.edu/~ota/disk1/1995/9561/956106.PDF

roughly paraphrased, "can't see your hand in front of your face." 

So even if BP dust is more "active" than corn dust and required less density (is it? would it?) it's not likely that we ever would have near that much suspended dust in our tiny little containers.

Thanks for your input.

[Skychief]

If this is possible, would it not be more probable to take place in factories which produce the powder versus the pound or less we generally carry in a vessel at a time?

[Mad Monk]

There are a lot of what ifs in this topic.
Most of what the shooter sees as dust in the powder is graphite.  Some powder makers use more graphite than others.
I used to see certain lots of powder where the surfaces of the grains were extremely dusty.
If the powder is properly polished there will be no dust from grains bouncing around in a container.  If you look at lots of the Swiss powder under a microscope it looks as if the highly rounded grains had been dipped in molten glass.  This glass-like surface appearance is where the term glazed powder first originated.  But then there are lots from other companies where the grain surfaces are rough and the grains have thin sharp edges that easily break with rough handling.  These grains may also have a lot of fine dust clinging to the surfaces that will fall off with movement of the grains.

In this subject of dusty powder think back to the days when I talked about "socking" the powder to clean it up.  These days you here nothing about that because the powder companies have cleaned up their acts in this.  Back in the 1800s the English and European powder makers were very careful about this dust thing.  In English powder plants they "reeled" the powder just before packaging it.  In what looked like very large fly fishing reels with cotton fabric suspended in the reel to hold the powder while the "reel" rotated.  Fine dust stayed in the cloth which was simply washed for reuse.  By 1997 I had the S/A Pernambuco Powder Factory throwing large pieces of cotton muslin into the polishing barrels during the final 30 minutes of the powder polishing cycle.  Removed all of the dust on the powder grains created during the first half of the polishing operation.

Bill K.

[WadePatton]

Thanks Bill (and others), that's enough for me.

Appears to me that dust of most varieties tends to be a nuisance at best, and a genuine problem/hazard at worst. Maybe it's never a hazard in our particular application, but then I'm not going to tempt it. 



Graphite-powdered socks just SLIDE right on.