Black Powder explodes by Shock ?

[Potassiumchlorate]

Strictly scientifically speaking, it's just impact if it's the kinetic energy from the hammer, sledge etc, that makes something explode.

[flying fish]

About the staple gun accident that has been published on the web...

 

(http://www.creagan.net/fireworks/safety_accident_from_pgi_bulletin.html)

 

If you read to the end there was some plausible sounding speculation that a spark created by the impact of the striker with the staple inside of the staple gun may have been the cause of the accident.

[taiwanluthiers]

Ok, Tried the hammer blow onto concrete floors with meal bp, nothing (I am more likely to damage the floor)

 

BTW just so you have respect for chlorates, potassium chlorate and sulfur will go off with a BANG with as little as 50mg when struck moderately hard with a hammer. At first I thought it was just going to deflagerate or something (because that's what you get when you light it with a match). 50mg was enough to cause ringing in the ear for about a minute. Was wondering if it's the hammer providing a bit of confinement or if it was the impact causing detonation. Even C-4 supposedly (I have not tried it) would not go off when struck with a hammer.

[TritonPyro]

I have heard here that a piece of 3 mm Visco ignited when chewed apart by blunt scissors. Do not know the truth of this, but do you think it could happen?

[Pirotecnia]

I have heard here that a piece of 3 mm Visco ignited when chewed apart by blunt scissors. Do not know the truth of this, but do you think it could happen?

 

 

Yes, theoretically it can happens, for example if the scissor makes some spark or extreme temperatures due to the friction of metal to metal.

Although, i think that rarely it can occur.

[mikeee]

I would love to see Bear Grylls start a fire in the wilderness with a pair of scissors or a staple gun.

Really hard to believe a miss-alligned striker in a staple gun could create a large enough spark to ignite the quick match fuse.

When using a pair of scissors while cutting a round object like a fuse it tends to spread the blades apart.

I would like to see some true science used to support these theories.

A static spark would be a more common occurrence for these types of accidents.

Globally, there are over 8,640,000 lightning strikes per day on the planet.

Many of these lightning strikes are very small and not viewable by the human eye in fair weather conditions.

Someone with a metal stapler in their hand would be a good conductor for a random mini lightning strike.

There are a number of white papers that have been published on these mini lightning strikes that create

problems on sensitive communications and electronics equipment world wide.

When a small cloud moves overhead it creates a potential charge between the earth below and cloud above.

Scientists are still trying to fully understand how it works in theory.

The other problem is the grounding of fireworks displays.

You build motar racks out of insulating wood, you install Polymer & Fiberglass mortar tubes in the wood racks

and drop paper insulated fireworks articles containing metal compounds inside the mortar tubes.

Polymer & Fiberglass materials are notorious static capacitive compounds.

Every item on a fireworks display should be on an equopotential ground plane to eliminate the static spark potential.

I hope no one from the ATF is reading this, They would create another chapter in the code book.

[Vsolon74]

I know it explodes with static electricity, I'm not sure about the other two.

[pyroshell]

I know for a fact that Black Powder will ignite from impact or friction if...

The impact has enough force to either cause an increase of pressure resulting in temperatures above ignition point.

Another thing that can cause ignition is sparks caused by the two objects hitting each other.

One last way which can happen more than you might hope is contamination. Simply if your black powder gets contaminated it is no longer standard black powder. It can become unstable for example in the anarchist cookbook he has “recipes” for black powder that are very unstable as they are not black powder. A small amount of chlorate can ruin a batch of black powder.

I once had a run in with what I think now was contamination. I used to have a ballmill. This mill had run a few hundred hours with no issues. It had the proper amount of lead media in it. (I used .50 musket balls from a gun store) It’s mill container was made from pvc pipe. Using disposable solo cups (they ware brand new out of the pack) I measured out my chemicals. In standard 75/15/10 ratio a started milling. About 30 min later a heard a loud boom. Upon inspection my ballmill had blown up.

So after a while I had thought of contamination as my cause so a checked for chlorates in my remaining samples of chemicals. The charcoal tested positive for chlorate. I did an execration afterwards on about 50 grams of charcoal and yielded about 5 grams of chlorate. ( do not typically work with chlorate , and this charcoal had no chance to have been contaminated by any of my other chemicals as I kept them separate and I am typically very careful. This was like this from the factory)

[taiwanluthiers]

What was the chlorate doing in the charcoal? Did they like leech it from H3 or something?

 

I guess you can still use it to make H3 just not bp.

[50AE]

This sounds scary if true. It means we cannot fully trust suppliers. It also means we cannot make quick conclusions. What if other BP related accidents were due to contaminations?

[dagabu]

I know it explodes with static electricity, I'm not sure about the other two.

 

Not necessarily true, a high dust situation allows a single dust grain to ignite but it would be difficult at best to ignite a pile with static, there is not enough heat (high voltage-low amperage). Keep in mind an impact test for Government Black Powder was firing a .30 caliber ball into a drum of BP without detonation.

 

http://www.youtube.com/watch?v=-5Z5yAeO3dw&safe=active

 

-dag

Edited January 3, 2013 by dagabu

[Mumbles]

Sorry but I have a hard time believing that you were supplied charcoal with 10% chlorate contamination. I can absolutely believe it had 10% water soluble ash however. How did you positively identify the chlorate and rule out other products?

[taiwanluthiers]

As in did you use the indigo carmine or MPAA test to determine the presence of chlorate compounds?

[TritonPyro]

Silence is deafening. There appears to be BS contaminating the BP.

[experienced]

the compression heating effect, would most likely be a cause of black nitrate powder ignition - like in a diesel engine compression. as you compress any substance, the heat flux becomes concentrated. and a sufficient impact, could easily reach critical ignition temperature.

[experienced]

No "might" about it - ammonium nitrate only detonates from shock. Interesting compound, every one of its constituent elements is a gas and it decomposes with an excess of oxygen. Exploding ammonium nitrate without a separate fuel component, eg dark aluminum, is a waste of a good resource. As others have said, straight potassium nitrate will never explode from shock under any circumstances. When it's compounded with charcoal and sulfur, however, it doesn't take a lot of friction heat to light it.

 

Two ways to detonate ammonium nitrate, 135*C +, and a high brisance shock. It takes more than a blasting cap, to detonate ammonium nitrate. It takes, a high velocity booster like tetryl. and a sledge hammer, would not likely produce the high velocity shock necessary. But i do not think, i would make a habit out of testing that theory. Would not be a good idea to use, ammonium nitrate for powder formulas. Since the temperature, would quickly exceed 135*C for even a medium size charge.

[experienced]

I think BP can be ignited from shock, though very much energy is needed to do it. Sulfur is the main sensitizer here. Normally this energy isn't obtainable in normal conditions, but I suspect it could happen even in some amateur cases, for example when you have a very sharp end (small surface) hitting. The pressure could be high - for example a sharp spindle of a rocket tooling.

 

Well i have detonated small amounts of, 5:4 yellow jack in a mortar and pestle. But i have never been able to detonate, 5:2:2 BP using lampblack in the same manner. As long as your nitrate, and sulfur, and charcoal or lampblack are pure. BP, should be relatively safe. But of course, the longer you allow powders to age the trickier they can get.

[TheOrb]

Okay. So..."YES IT CAN HAPPEN"!

No f'n spark or ignition AND..you will always know the difference between Detonation and Conflagration unless you are deaf AND also bereft of a nervous system.

As with most..I have gone on the premise that BP will not Detonate under percussion. I am now enlightened.

As a general rule of thumb I take .1 -.2 gm. of BP Rocket comps. and such to task by folding them up tightly in a bit of Al. foil and giving them a square smack on a masonry block.

Last week I was horrified when a 61% KNO3 12 S and 1.5 RedGum with majority Lampblack fuel....BANGedddd.

I dunno....I repeated the performance...twice.

Maybe contamination in my musket ball mill media lead?? But needless to say I am not ramming the mix. I threw in they balance of course C and Denatured damped it.

Horrible shit...burns like a banshee though after drying.

 

Now. I will qualify this by adding that SPECIFIC FORMULATION AND/OR CONTAMINANT(S) may be responsible for such incidents and there is AMPLE EVIDENCE and DEATHS to support CAUTION.

 

IF YOU DON'T HAVE TIME (3 Mins.)TO DO A SIMPLE FRICTION AND PERCUSSION TEST ON NEW BP COMPS...YOU CERTAINLY SHOULDNT BE WORKING IN PYROTECHNICS TO BEGIN WITH.

MOST ACCIDENTS OF ALL TYPES ARE CAUSED BY OVER CONFIDENCE AND FAMILIARITY.

DOING THE SAME THINGS WE USUALLY DO...SOMEWHERE A VARIABLE ENTERS AND FOLKS DIE.

DONT BE ONE OF EM.

Edited June 18, 2021 by TheOrb

[justvisiting]

 

Here's a possible explanation.

[TheOrb]

Yes. Thanx..."Just Visiting". I was psyched on using these beastly .735 Dia. Musket Balls and ...while I did give them an hour run with some Baking Soda to clean em up...on inspection was concerned about some brown spots and apparent impurities.

Probably cast from scrap and contain some Iron or oxides thereof. Who knows...a LITTLE excitement keeps us on our toes.

Still...I have ALWAYS refuse to EVER say that BP is friction nor percussion insensitive etc etc.

I read through this thread and...while this is not intended to offend anyone..rather save them,(and I no lover of the Human Race) BUT

PLACING YOUR HEALTH AND LIFE IN THE HANDS OF A CHEMICAL/MATERIAL SUPPLIER REGARDLESS OF THEIR REPUTATION IS PATENTLY MORONIC!

You gentlemen gawking in disbelief at charcoal with Chlorate impurities etc need a reality check.. you are NOT purchasing Reagent or Lab grade chemicals and generally NOT dealing with suppliers at the....higher end of the gene pool either.. Facts.. Sorry..

Now...Yeah I was 13 yrs old once..equipped with a Sulfur glazed old Mortar and Pestle. I milled up many a batch of Chlorate while listening to the crackles and pops.I was lucky and dealing with a few grams and learned better very quickly.

I DID however nearly lose my life if not at least my right eye,

at 18 due to a bad batch of "Safety Fuse".I did lose my hair and suffer 3rd degree burns from a 100 gm. BP/Mg flash pot.I have permanent scar at the T shirt lines at my neck and right bicep.

Not to mention having to clean and repaint the bathroom of the persons apt. I burst into to douse my burned clothing and skin.

I might have preferred an explosive death to sitting n the hospital to have burned skin peeled off and the weeks following.

Just...test your shit people. This is not a video game.