Reloading Kaboom Yesterday - Please Learn From This

[Motor Man]

That must have hurt like the devil one you realized what had happened. Glad it wasn't worse and that you've healed up somewhat okay.

[uhlan1]

I'm glad you're ok but am finding this thread fascinating.

[Pauliedad]

Thanks for this.
Just like you stated, I HAVE to know what happened when something unexpected happens to me.
I'm a general contractor that is very hands on and have learned a heap from others mistakes. Mine too, of course but I always need to learn from others screw ups. If I can avoid some situation by hearing a story and taking away some lesson, then it's a good day.
I've been reloading for a little over a year now and still remember all I read about the primers being the most dangerous part. I see some alligator clips and copper wire in my future.
Again, thanks for sharing you experience and good luck getting back into it.

[StuckInTheP.R.O.Ca]

I haven't even started reloading yet and I'm already paranoid after reading this.

[call-in]

I just saw this thread for the first time, and am coming in late. But from the first post, I knew what had happened. This was a case of static discharge that was enhanced by the very low humidity on the day it occurred. Somehow a static charge was built up in the tube and even if it didn't come into contact with the press, it got close enough for a spark to jump across. There may have been lead styphenate dust in the tube or the spark was close enough to a primer to ignite.

Here is a brief explanation of why low humidity enhances the build-up of static charges:



It was the lack of moisture in the air that allowed for a significant charge to build up. Being an engineer in the rocket biz, I have worked with rocket propellants for three decades-hydrogen and oxygen, and have seen this phenomena "in action". As a safety precaution, we won't transfer or use propellants when the RH goes below 30% even though we thoroughly ground every piece of equipment.

One way to avoid a recurrence would be to ground the tube to the press before loading primers with a length of copper wire and a pair of alligator clips. That way the charge would equalize between the two before the introduction of primers......... either that or check the weather before you get out the reloading gear.

hth

I'm fairly new to reloading and just a little confused. With your background maybe you can explain this topic more clearly. I thought the priming compound would be the last thing that would react to static electricity in that it in itself is surrounded by a metal cup which is then surrounded by a metal tube, unless the priming compound has a lower resistance than the metal cup and tube, shouldn't the current flow around the priming compound?

[Darto]

My experience is mainly with black powder and reloading for old guns, including cartridges on a press. In reading forums online I have seen more than one experiment where the tester utterly failed in a deliberate attempt to set off BP with static electricity.

I never used a auto primer of any kind, nor even a disc that holds primers on a hand priming tool. Maybe mine is an unreasonable fear...

My other one is the double charge and so try to use a bulky powder that won't fit a double charge into a metallic cartridge case. I am spooked whenever loading brass shotgun shells, fearing a double charge.

[Eljay]

I haven't even started reloading yet and I'm already paranoid after reading this.

A little paranoia's a healthy thing with reloading, especially with these primer tube systems.

[3006mv]

When I hear pull pin and kaboom I always picture grenade

[sofbak]

I'm fairly new to reloading and just a little confused. With your background maybe you can explain this topic more clearly. I thought the priming compound would be the last thing that would react to static electricity in that it in itself is surrounded by a metal cup which is then surrounded by a metal tube, unless the priming compound has a lower resistance than the metal cup and tube, shouldn't the current flow around the priming compound?

It wasn't the current flow that ignited the lead stypenate, it was the heat from the spark that jumped from the tube to the press (or vice versa). While very short in duration and definitely "localized", the spark is also very, very hot. Think of it like the spark plug in an internal combustion engine. The current flows through the center electrode, jumps an air gap (as a spark) and flows through the side electrode. It is the spark that occurs over the air gap that generates enough heat to detonate the fuel/air mixture, not the current flow through the metal parts.

As I mentioned, the spark was either in the presence of enough lead stypenate dust in the tube, or it occurred very near to the open end of one of the primer cups where the heat could ignite the exposed material. I'm leaning towards the dust presence based on the OP's description of what he was doing at the time. It wouldn't take much dust to start the combustion process.

Here is a web page that shows how a quantity of dust can be relatively safe in one state, and incredibly explosive when dissipated in air where there is a lot of surface area exposed, and sufficient oxygen to support rapid combustion-similar to grain dust explosions in elevators (or lead stypenate dust in a tube).

http://www.angelo.edu/faculty/kboudrea/demos/lycopodium/lycopodium.htm

hth

[grant22]

Reloading Kaboom Yesterday - Please Learn From This

Sofbak,

Just make sure I'm clear, do you think:

-heat from spark ignited the dust? Then
-mini dust explosion ignited a primer/multiple primers OR
-mini dust explosion shocked a primer/multiple primers?

Regardless, I'm definitely thinking every time I clean the 550 machine it might be a good idea to clean the primer tubes, also.

[sofbak]

Sofbak,

Just make sure I'm clear, do you think:

-heat from spark ignited the dust? Then
-mini dust explosion ignited a primer/multiple primers OR
-mini dust explosion shocked a primer/multiple primers?

Regardless, I'm definitely thinking every time I clean the 550 machine it might be a good idea to clean the primer tubes, also.

I have no idea what the secondary process was after the initial ignition. It's plausible that both may have been in play. Given the detonation velocity of lead styphnate (5200 m/s-see link below), I would be inclined to think that the flame front ignited them rather than an impact shock, as the flame front would be moving through the tube much faster than the primers could accelerate-but who knows for sure.

http://en.wikipedia.org/wiki/Table_of_explosive_detonation_velocities

Did you come across any un-detonated primers-maybe one or more in the ceiling? That might be a clue.

Cleaning the primer system before and after each session is probably a good idea in light of this event-as is grounding conductive tubes before handling/loading primers. My system is Lee and all plastic, but after reading about this, I'm going to give it a good rub down with an anti-static dryer sheet before each loading session.

This event was a classic freak of nature where a set of individually unique circumstances came together at precisely the right time to create a catastrophe. I'm thankful you didn't suffer any worse for it, and also very appreciative that you shared it here. I have a lot more respect for the hazards of the process now, and will certainly take extra steps to avoid a similar event in my garage.

[grant22]

Reloading Kaboom Yesterday - Please Learn From This

All primers were spent (charred and anvils/cups were separated). Hell, one anvil was lodged in my thumb 'metacarpal' bone. That bastard hurt.

Yes, this was a 'planets were lined up' for the 'perfect storm.'

[call-in]

It wasn't the current flow that ignited the lead stypenate, it was the heat from the spark that jumped from the tube to the press (or vice versa). While very short in duration and definitely "localized", the spark is also very, very hot. Think of it like the spark plug in an internal combustion engine. The current flows through the center electrode, jumps an air gap (as a spark) and flows through the side electrode. It is the spark that occurs over the air gap that generates enough heat to detonate the fuel/air mixture, not the current flow through the metal parts.

As I mentioned, the spark was either in the presence of enough lead stypenate dust in the tube, or it occurred very near to the open end of one of the primer cups where the heat could ignite the exposed material. I'm leaning towards the dust presence based on the OP's description of what he was doing at the time. It wouldn't take much dust to start the combustion process.

Here is a web page that shows how a quantity of dust can be relatively safe in one state, and incredibly explosive when dissipated in air where there is a lot of surface area exposed, and sufficient oxygen to support rapid combustion-similar to grain dust explosions in elevators (or lead stypenate dust in a tube).

http://www.angelo.edu/faculty/kboudrea/demos/lycopodium/lycopodium.htm

hth

That's an answer I can respect. Thanks.

[mike_the_wino]

Wow, first time reading this. Thank you for this very important reminder. I am glad to hear that you have recovered. Even if your thumb isn't 100% at least its there, right?