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SENSITIVITY OF BLACK POWDER TO
STATIC DISCHARGE

By Wayne McLerran
Posted 4/14/18

It’s been many years since I designed and published an article on a semi-automatic
black powder (BP) loading system consisting of an electronic powder dispenser,
digital scale, fiber optics cable, a tall stand and a drop tube.  By pressing a single
button the dispenser trickled out a precise charge of BP down the drop tube into the
case setting on the digital scale platen.  The dispenser stopped when the scale
registered the programmed powder weight to within +/- 0.1 grains.  Knowing this, a
fellow shooter recently asked if I was concerned about using the setup with black
powder since the dispenser is constructed out of plastic and has a plastic reservoir
which potentially could build up a static charge.  Prior to building the loading
system and due to a similar concern, I researched the subject extensively,
experimented with subjecting BP to high voltage static discharges, and was
convinced that any static charge created by the dispenser would not be sufficient to
ignite BP.  20 years later I continue to use the same setup without any problems.  
But the subject continues to come up in many of the online BPCR forums and is
therefore worthy of additional discussion.

My experiments with attempting to ignite BP consisted of the following.  Using
Goex 2Fg and 3Fg I first pounded it to dust with a hammer with no reaction.  
Several piles of the dust were then subjected to high voltage discharges of
approximately 100,000 volts with a hand tester used to test static discharge damage
thresholds in integrated circuits.  The discharge caused some of the small granules
to move but none of the samples ignited.  Around the same time a fellow by the
name of Barry Bush published two excellent and lengthy articles on BP safety in
the 1999 spring and summer editions of The Black Powder Cartridge News.

Mr. Bush is obviously a very knowledgeable guy and did a good amount of
experimenting to determine the sensitivity of BP to heat, pressure and static
discharge ignition.  He found BP much more sensitive to heat than smokeless.  He
also found that BP is not very sensitive to shock, and is much less sensitive to high
voltage sparks than smokeless powder.  Barry passed sparks of up to 20,000 volts
directly through BP with absolutely no ignition.  Goex Fg, 2Fg, and 4FA (unglazed
powder) BP was used.  The 4FA powder was used to see if the lack of graphite
would allow the powder to ignite.  He said that it is conceivable that a 100,000-volt
spark from a fingertip could ignite BP, but the chances are very remote, which I
proved to myself by my experiments detailed above.

In summary Barry said, “Many common perception of black powder come from
those who lack practical experience, and they often reflect confusion with other
explosive materials.  Modern smokeless powder has an excellent safety record, but
in some respects smokeless can be more dangerous than black: it is more likely to
give extreme pressures from an overload, more susceptible to decomposition, and
under some conditions, more sensitive to electrical discharges.”  In closing he
further stated, “Black powder has managed to outlive most of its detractors, and
hopefully will continue to do so.  Meanwhile, shooters can ill afford to repeat
folklore, speculation and hearsay which may come back to haunt them.”  The last
sentence refers to past and possible future government regulation on BP due to
incorrect and misleading information.

To further reinforce the above comments that BP is not sensitive to static
discharge, go to the following links at the Connecticut Muzzleloaders website:
http:
//www.ctmuzzleloaders.com/ctml_experiments/sparks/sparks.html
and http://www.
ctmuzzleloaders.com/ctml_experiments/electric_ignition/eignition.html
.  The spark
experiment is similar to the ones both Barry Bush and I ran.  The key to
understanding the differences in the two ctmuzleloaders.com experiments is the
high voltage sparks in the first experiment and those in Barry Bush’s and my
experiments do not contain sufficient energy (power) to heat the BP particles to the
ignition point.  Electrical power (measured in watts) is the combination of voltage
and current.  Static discharges generated from friction on plastic containers or
sliding ones foot on carpet and touching another object are typically at very high
voltages but the current levels are very low.  The second ctmuzleloaders.com
experiment was based on using a capacitor, an electrical energy storage device to
ignite the powder.  Although the voltage level was significantly lower the capacitor
provided a much higher current source when discharged through the powder, which
was sufficient to heat the powder to the ignition point.

Another question that comes up now and then is based on concerns about static
buildup on plastic containers used for shipping and storing BP, especially when
pouring the powder out of the container.  What many BP shooters do not realize is
the containers are made of antistatic plastic.  Although antistatic plastic can be
made in several colors, clear, red, etc., the plastic containers BP is shipped in are
typically black and contain small amounts of carbon to make the plastic slightly
conductive to electricity (antistatic).  So pouring BP out of the containers cannot
build up a static charge.

The development of antistatic plastic was the result of the semiconductor industries
need to reduce the cost of shipping integrated circuits (ICs) in the 1980’s, which
were commonly shipped in "conductive" aluminum tubes at the time.  Some ICs
are sensitive to even low levels of static discharge.  Most of my career was spent
in the semiconductor industry and I remember reading at the time that materials
with a surface resistance of as much as several hundred thousand ohms per square
inch would drain away any static charge.  Using a standard VOM (volt ohm meter)
or multi-meter, one can actually determine if the plastic used in BP shipping bottles
is antistatic.

While writing this article I grabbed a black plastic bottle of Swiss 1.5Fg and my
handy Harbor Freight multi-meter, the one they give away if you purchase anything
at the store.  With the meter set on ohms and the sharp-tip probes inserted into the
plastic about an inch apart, the resistance was around 300,000 ohms, sufficient to
eliminate a static charge buildup.  Just to double check, I also used an expensive
multi-meter with the same results.  By the way, typical non-treated plastic is an
excellent insulator (has extremely high to infinite resistance) and therefore will not
drain off a static charge unless ambient humidity levels are high; it’s wet or
sprayed with a conductive material, which brings me to some solutions if you are
still concerned about static charges building up and igniting BP.

Plastic powder-dispenser reservoirs can be lined with aluminum foil, sprayed with
Static Guard or other brands of antistatic sprays to lower the surface resistance and
drain off static charges.  Spraying with a water-diluted detergent solution and
allowing the surface to dry will temporarily eliminate static buildup as will wiping
with a fabric softener sheet used when drying clothes.  Or go to the following link
(http://www.instructables.com/id/Creating-Anti-Static-Spray/) to easily make a
solution from three common household ingredients.

I'm certainly not suggesting one can be careless when using BP, but the
experiments discussed here and the additional information presented should cause
you to reconsider the warnings and unsubstantiated myths we in the shooting
community have been passing around about BP safety.

Wishing you great shooting,
Wayne