From: glhurst@onr.com (Gerald L. Hurst)
Newsgroups: rec.pyrotechnics,alt.engr.explosives
Subject: Re: Current fired compounds

>I haven't attempted to test anything like this, but I suspect you could
>create a conductive pyrogen mix using aluminum or copper powder (must
>be in high enough proportion that the grains touch to form a current
>path).  Unfortunately, there is a strong likelihood that you'll need
>either very high current, or very high voltage (due to high resistance)
>to ignite the pyrogen in this type of device -- which is not exactly
>what you're after in terms of reducing the weight of batteries lofted
>in the rocket.

Black powder is conductive unless treated, at least to high voltages.
Years ago a ski patrol avalanche controller was severely injured or
killed by a charge of dynamite he intended to throw. The problem was 
that his organization had been forced to purchase foreign made safety 
fuse when U.S. supplies dried up. The two feet or so of untreated 
black powder in the fuse conducted static electricity into the fuse 
cap.

These fellows used to ski along with explosive charges equipped with
safety fuse and pull igniters. On the fly they would yank the 
igniters and throw the charges into snow banks. Geronimo!

One of these days I'll relate the case of the avalauncher which
exploded and killed its crew. This device was a ten foot-long
cousin of a potato canon that could toss an explosive projectile 
a mile or so to precipitate timed avalanches.

Jerry

From: glhurst@onr.com (Gerald L. Hurst)
Newsgroups: rec.pyrotechnics
Subject: Re: Ammonium Perchlorate
Date: 20 Jan 1996 21:57:56 GMT

In article <ftn_2.200.235.0_13efdcd3_Sweden@synchron.ct.se>,
sweden@synchron.ct.se (Sweden) says:

>It's a material used by military forces in the event of war. BP is
>an US strategic material and have to be manufactured in the US _by_law_.
>This is why Goex still have their manufacturing license, although
>they have explosions occuring from time to time. But all the other BP 
>plants have lost their licenses - one after the other - when they had
>explosions. BP is used in the US space programe.

Sweden, that is a very Swedish idea. The other companies did not
stop manufacturing BP because they lost their licenses, they
quit because they lost their plants, and the market would not
justify the capital investment required to rebuild.

The U.S. Government operates it's own explosives manufacturing
facilities for most explosives. In times of war, commercial
manufacturers frequently retool to make military explosives.
BP is mostly used in small military applications such as delays
and lift charges. They may indeed buy from Goex, but if you want
to set up a competing plant in the US, you'll have no trouble
getting a license. 

I came very close to putting a group of investors together
to buy the Goex facility a number of years back. They
were kind enough to give me a plant tour for the benefit
of the potential investors.

Jerry (Ico)

From: glhurst@onr.com (Gerald L. Hurst)
Newsgroups: rec.pyrotechnics
Subject: Re: Striker Anywhere Matches .... ?
Date: 18 Mar 1997 21:04:18 GMT

In article <332EEF7C.768F@ix.netcom.com>, The Silent Observer
<silent1@ix.netcom.com> says:

>No, Jerry, I wasn't you who led me down that path -- I read about the 
>trick someplace in about 1973, when I was all of 13 years old and a 
>newly minted high school freshman.  I've since learned that it was indeed 
>a dirty window that thwarted my efforts, but I was using the correct 
>technique, including have figured out a grip that would leave me still in 
>firm control of the match after ignition and rapid retreat of my middle 
>finger (which was clamping the match head against the glass).  I was 
>interested in the trick, not in burning anything down...

Sigh, in 1973 I was too old to be a hippy.  Lemme see, ahhh yes, my
Kinepak patent had just issued and I was about to start work on the
so-called "Mylar balloon."  The President of kinetics International
sent me to Maylaysia, Indonesia, Singapore for two months of shooting
in the jungle to make sure I didn't screw up the sale of Kinetics to
the company that was planning to merge us with Atlas.  Shortly 
thereafter the new outfit made me chief scientist of Atlas and let 
me open my own explosives lab in Austin to get my bad influence away 
from the home office.  I guess I really am a fossil.

>It was shortly after this that I attempted to make black powder by the 
>Captain Kirk method (throw the ingredients together, stir by shaking, and 
>ignite) with astoundingly poor results -- a 4-inch length of pants hanger 
>tubing filled with my mix took almost two minutes to burn out when 
>ignited with a firecracker fuse, and left a lot of white residue.

I too made what I thought was black powder at about the same age.  Back
then it was absolutely no problem to buy whatever chemicals you needed
at the local drugstore.  They still stocked all the old nostrums and
snake oil in the brown bottles with rococo labels.  Saltpeter came in
a tin.  the ancient druggist would always waggle an admonishing finger
and say, "I know what you're doing."  Of course, he always said the
same thing when I bought oil of anise and seemed much more disapproving
of the illegal use of stinkbait than at the thought of a kid making
black powder.  You can bet he did the same thing 60 years earlier.

It is a very good thing that I didn't know about milling, dampening
and pressing the green powder or I surely would have wound up with
a hide full of CO2 cartridge pieces or the like.  Of course, I built
a couple of rolled newspaper "rockets" which would spew long enough
to get boring.  As I recall, Captain Kirk used diamond in one episode.
He must have had a devil of a time getting it ground fine enough
to make green powder.

Jerry (Ico)

From: glhurst@onr.com (Gerald L. Hurst)
Newsgroups: rec.pyrotechnics
Subject: Re: Black Powder Query
Date: 27 Nov 1995 03:27:56 GMT
Organization: Consulting Chemist

In article <DIo69r.BJ3@eskimo.com>, victim@eskimo.com (Tony Garton) says:

> If you dry this ball 
>(and it will dry very quickly) you can 'grate' it through a screen (you 
>can also do this when it's still wet with alcohol, it will be safer that way)

[Snip]

>    I have some questions about BP maybe someone can answer.  It's been 
>said that using charcoal is a lot better than using pure carbon because 
>of about 10% impurities that help the BP.  Has anyone nailed down what 
>these are and what they do for the reaction?

Alcohol has a flash point below room temperature. Mixtures of 
alcohol and BP deflagrate very nicely as is shown in the classic
"proof test." Therefore, mixtures of alcohol and BP have
have additional hazards as compared to BP.

Charcoal is porous; graphite is not. It follows that charcoal
absorbs reactants better and presents a greater reacting 
surface area.

Jerry

From: John De Armond
Newsgroups: rec.pyrotechnics
Subject: Re: Need comments on firework...
Keywords: safe, sound
Message-ID: <5304@rsiatl.Dixie.Com>
Date: 18 Dec 90 21:33:55 GMT

flax@Mizar.DoCS.UU.SE (Jonas Flygare) writes:


>I'd like comments on the following..

Ok.


>First, I would clear the area around the sink (stainless steel, and sink
>filled with water in case I need to dispose of anything..)

I would not do this inside.  I'm not as concerned with the fire hazard
as I am with the force of any possible explosion being contained and
of the damage an explosion could do.  I have experienced an explosion in
a closed room and it is not pleasant, especially for your ear drums.

>I wouldn't want to use ethanol (flammable, and it's smelly..) so I mix the
>ingredients in a plastic bag + water to moisten it (should be like a thick
>paste)

Ethanol would be safe enough and would greatly speed the drying process.

>I would then take some 5 grams at a time and grind (no metal!) to get rid of
>any lumps (the sulphur is hell to prevent from forming small lumps! :-)

I read a detailed process description of how the new company that took
over Dupont's black powder plant makes black powder.  They do the process
quite similiar to yours except that they roll mill the mixture in a
wooden vat with wooden rollers.  I'd suggest something similiar.  They
add a bit of graphite to the mix after rolling for a variety of purposes,
one mentioned is the  reduction of static (why won't the charcoal work?)
during the tumbling  and sizing process.  They also stated that the
graphite controls the burning speed.

>The batch (max 20 grams at a time) would be allowed to dry for some days.
>For this purpose I would use a box, with desiccant bags.
>Would work really nice.

The Dupont process involved tumbling the rolled powder in a rotary kiln
with warm air blowing through it.  You could do something similiar at
home with a wooden gem polishing drum.

Otherwise, with the details you gave, things seem to be in order.  The
other thing I'd suggest is that you pay attention to process segregation.
IN other words, make sure you keep your batches and work in progress
sufficiently segregated that a fire in one cannot ignite any others.
Small, open top bunkers work well for this.

John

From: chem2149@waikato.ac.nz
Newsgroups: rec.pyrotechnics
Subject: Re: Making BP: Step by Stepy
Message-ID: <1991Jul3.113902.4149@waikato.ac.nz>
Date: 2 Jul 91 23:39:01 GMT

In article <1991Jul2.003422.31839@kuhub.cc.ukans.edu>, mauler@kuhub.cc.ukans.edu writes:
> I'm sorry; I should have mentiopned that the KNO3 in the recipe I have came as
> little round pelletrs, from a 50lb bag of KNO3 fertilizer.  The reason there

For all my black powder manufacture I also use fertilizer grade KNO3 but since
the purity is around 95% I recrystalize all my KNO3 from hot water.

I have found a range of unwanted products in fertilizer grade KNO3, these
include KCl, NaCl, NaNO3, sulphates, carbonates, sand, iron oxides, flow agents
etc. They claim only 95% purity and thats what you get with fertilizer grade.

With the use of recrystalized KNO3 you will get less water absorption (if you
live in damp climates) and a small increase in power. I find the added work
necessary for my pyrotechnic effects.

You may not need to worry about this factor at the moment since you are making
small quantities more for fun.

I use a 20 litre drum for my willow charcoal manufacture. I build a large open
fire around the drum and destructively distil the wood until no flame is
visible from the opening, generally one hour of burning. The drum is red hot at
the final stages. This produces about 1.2 kg of very clean high quality willow
charcoal. On the farm it is a little easier to build such a fire, if you live
in the city you best find a friend outside of city limits. A batch of charcaol
is enough for 8 kg of black powder.

I produce my black powder in 1 kg batches using hardened lead balls (200) in a
ball mill. Mill time for good black powder is 6 hours, all components together
from the start. Never had any trouble YET, in over 40 batches. I initially
started using 1% water but my ball mill caked-up after 3 to 4 hours, now I dry
mill with no problems. Safety aspect, turn it on walk away, when the time is up
go back and turn it off. Makes enough noise to know thats its working.


KNO3       70%
Charcoal   30%   (Willow)

This is also worth putting through the ball mill as it is a very good rocket
propellant, and if the powder grains are made at smaller mesh sizes it is as
good or better than normal black powder (75/15/10).

Any one care to discuss the effects that different charcoal woods have on the
burning rate of black powder. I vagely remember reading a little on this a long
time ago. It would be nice to have a summary posted here.


MARTIN VAN TIEL     PhD Chem

From: chem2149@waikato.ac.nz
Newsgroups: rec.pyrotechnics
Subject: Re: Charcoals
Message-ID: <1991Jul31.123605.4500@waikato.ac.nz>
Date: 31 Jul 91 00:36:05 GMT

In article <7183@hplabsz.hplabs.hpl.hp.com>, schediwy@hplabs.hpl.hp.com (Bic Schediwy) writes:
> The quality of B.P. is affected by the type of charcoal used. Willow,
> hemp and a few others are preferred types.

Hemp charcoal is a poor quality charcoal, contains a large amount of ash.
Willow, poplar, etc woods that contain very little gums or resin are the best
for black powder manufacture.  These type of charcaol are readily powdered and
have a very porous structure.  This allows better incorporation of the KNO3.
Woods that contain gums and resins form some non-porous carbon (more like
coal).

>
> Does anyone know where mesquite fits into the spectrum of charcoals.
> My thought here is that there is a cheap plentiful supply available
> at any grocery store. This charcoal is not in the form of briquettes
> but instead is actual chunks of "charcoalized" wood. If mesquite is
> a good charcoal, then B.P. can be made for next to no cost with a quick
> trip to the fertilizer and grocery store. Note that charcoal briquettes
> don't make good B.P. They are made from unknown wood(s) and also contain
> an inert filler (clay I believe).
>
> (A side question: What type of wood is airfloat charcoal made from?)

I dont know what type of charcoal you get with the above trade-names but the
briquettes form seems to be rubbish for black powder.  The mesquite brand seems
to be OK if it looks like chared wood and is very light in weight.  Break the
charcoal in half and check that it is fully converted.  It should snap and have
no brown colouration.  I have seen some charcoal/wood, black on the outside
wood in the centre.

I make all my charcoal from dried willow.  I fill a 20 litre drum with split
willow (size approx 0.5"x1"x6") and build a large fire around the drum, in one
hour the destructive distilled wood flame is a weak blue colour and the drum is
red hot, the process is complete.  CARE do not screw cap on drum while heating,
gases need to escape.


What I would like to know is the burning rate of black powder when using
different types of charcoal?

Dr Martin L. Van Tiel    Ph.D  Chem

From: chem2149@waikato.ac.nz
Newsgroups: rec.pyrotechnics
Subject: Jet Mill - Black Powder
Message-ID: <1991Aug22.122523.4720@waikato.ac.nz>
Date: 22 Aug 91 00:25:23 GMT

In article <22810174@hpcvaac.cv.hp.com>, billn@hpcvaac.cv.hp.com (bill nelson) writes:
> ahahma@polaris.utu.fi (Arno Hahma) /  9:56 am  Aug 16, 1991 / writes:
>
>>The US army black powder mill runs continuously and produces even
>>better quality BP than the conventional ball mill- edge runner-
>>process. Ever heard about jet mills?
>
> No, I have not kept up with modern large scale production methods. Do
> you have a reference list? I am certainly interested in the jet mill.
>

Jet mill air-attrition process has no moving parts concerned with the size
reduction section and has replaced the wheel-mill operation of the conventional
process.  Potassium nitrate, sulphur and charcoal are automatically weighed by
transferring each ingredient to a weighing and mixing bin with a vibrating
transporter.  Air jets are applied to the bottom of the weigh-mix bin to blend
the components.  The air-pressure is then increased to continuosly transfer the
mix pneumatically to a storage bin and then to the jet mill by air injection.
A high velocity stream of air entering the mill forces the particles to collide
and breaks them up by attrition.  The product consists of a finely divided
powder.  The small particles exit through a cyclone separator where they are
separated from the air.  Coarse particles drop back to the attrition section
where the milling action continues.  The mill may be adjusted to produce
powders of different granulations.
Pressing, corning, screening and glazing are comparable to conventional
process.
Safety : Deluge systems activated by UV light respond in milliseconds.
Particle sizes : The attrition mill produces particles less than 10 mircon.
The attrition process can produce particles as small as 0.1 mircon.

Dr Martin L. Van Tiel      Ph.D. Chem


Arno, how is the rocketry side of things going.

From: ahahma@polaris.utu.fi (Arno Hahma)
Newsgroups: rec.pyrotechnics
Subject: Re: Re: nitric acid question & soapbox
Message-ID: <1991Aug23.163323.13661@polaris.utu.fi>
Date: 23 Aug 91 16:33:23 GMT

In article <22810174@hpcvaac.cv.hp.com> billn@hpcvaac.cv.hp.com (bill nelson) writes:

>used to know a person that made about 2 ounces of lead azide. He put it
>on top of his refrigerator while he was making some caps. The freezer
>started running and the container of azide walked off the edge. You can
>imagine the damage it did to the garage when it exploded as the container
>hit the floor.

And I know a person, who didn`t know acetone peroxide evaporates at 56
oC. He dried about 1/2 kg it in an oven, at 100+ oC, since water boils
at 100 . Unfortunately, the thermostat sparked.... You can NOT
imagine, what the kitchen looked like after that :-) (yes, I know I
shouldn`t laugh at it).

>I think the procedure would be highly interesting to people interested in
>pyrotechnic mixtures that are flame or spark sensitive. Would you consider
>telling us more about it?

Martin already did most of that. Newer jet mills do not use a cyclone
for fractionating the particles during the run, the cyclone is there
only to collect the finished product. There is no feedback from the
cyclone. I can post a reference to a report about the process next
time, I don't have it now. There is a schematic picture of the mill,
too.

It is quite possible to build such a mill, for example using
sandblasting apparatus for the nozzles and injectors part. The most
expensive part of the mill is the air compressor.

The jet milling process is quite effective. A single jet mill replaces
ten ball mills and edge runners, and the mill is physically about of
the same size as one edge runner.

>Bill

ArNO
    2

From: ahahma@polaris.utu.fi (Arno Hahma)
Newsgroups: rec.pyrotechnics
Subject: Jet milling process for BP manufacture
Message-ID: <1991Sep9.162352.11925@polaris.utu.fi>
Date: 9 Sep 91 16:23:52 GMT

I promised to post references about the jet milling process for
manufacturing black powder. A nice introduction to the process (with
some pictures, but unfortunately no further references) can be
found in the Meeting Report Joint Symposium: Compatibility
of Plastics/Materials with Explosives and Processing Explosives,
by the Materials and Processes Division of the American
Defense Prepardness Association, Marriott Inn, Blacksburg, Virginia,
October 1980.

_______________________________________________________________________________
_____  _____  _____
|   |__|   |__|   |           A. Hahma
|                 |           Research Centre of the Defence Forces
|_________________|           Department of Chemistry
 |       .       |            Laboratory of Propellants and Explosives
 |   .       .   |            BOX 5
 |       .       |            SF-34111 LAKIALA
_|   .       .   |_           Tel. +31-492177
|        .        |
|                 |
|_________________|

From: chem2149@waikato.ac.nz
Newsgroups: rec.pyrotechnics
Subject: Black Powder, Wet Method
Message-ID: <1991Oct29.105836.5312@waikato.ac.nz>
Date: 28 Oct 91 21:58:36 GMT

In article <1991Oct24.185514.1@husky1.stmarys.ca>, gen4044@husky1.stmarys.ca writes:
>  This started a gear or two in my head... What if I used a common Alcohol
> instead of the water, something like Isopropyl (Rubbing Alcohol) to create the
> solution. With minor heat, this could easly be dried to the point where the BP
> is a wet sludge on the bottom of the container, then leave it there for a few
> minutes, until the Alcohol evaporates.
>
>  Problem is I'm not sure what the KNO3, S and Charcoal dust will do in a
> solution of Alcohol. I belive they will ionize, but am not sure.
>  The ideal thing would be to test this, but as a busy student (who spends too
> much time on the Vax) I don't have the time to give it a whirl. Besides, it's
> generally not a good idea to just whip things together without understanding
> what is going on. The Mix sounds pretty safe, but then again, you won't see a
> Ph.D. after my name for a while.. :-)

The correct method is to get very finely powdered charcoal and sulphur and mix
into a warm to hot saturated solution of KNO3. When a homogenous mix is
obtained this hot solution is added to a rapidly stirred ethyl alcohol solvent.
The amount of alcohol should be a least the same or more than the amount of
water. This causes an immediate precipitation of the KNO3 from solution.
Charcoal, sulphur are insoluble in both water and alcohol. KNO3 is very
sparingly soluble in water/alcohol mix. The amount of KNO3 left in solution
will hardly alter the initial weights.  The next step is to vaccum filter the
resulting precipitate, wash with a little 95 to 100% alcohol and leave to dry.
This should result in a very good grade of black powder with very little
hazzard in manufacture. The alcohol can be recovered by distillation.

This method reqiures some equipment, all this can be improvised with a little
thought if money is tight. Access to lab equipment will make life easy.

Dr Martin L. Van Tiel   Ph.D. Chemistry  (I do have a Ph.D. after my name
                                                                 finally)

From: ahahma@polaris.utu.fi (Arno Hahma)
Newsgroups: rec.pyrotechnics
Subject: Re: Re: Black Powder, Hot method
Message-ID: <1991Nov14.180218.10777@polaris.utu.fi>
Date: 14 Nov 91 18:02:18 GMT

In article <22810278@hpcvaac.cv.hp.com> billn@hpcvaac.cv.hp.com (bill nelson) writes:

>njs@scifi.uucp (Nicholas J. Simicich) /  6:36 am  Nov  7, 1991 / writes:

>>>The corn the powder, screen it for size and then tumble it with graphite
>>>to glaze the grains. After it is glazed, it is screened for size once more.

Actually, they first let it tumble to break off the sharp edges. Next,
they sieve it to remove the dust and then tumble it with graphite to
give the powder its glaze.

>>Um, I was always under the impression that the graphite was there to
>>act as a conductor.  People believe that when you tumble black powder,
>>it can build up static charges internally.   The graphite powder is
>>there to act as a conductor so that the charges bleed off to the
>>conductive container that the powder is in when it is being tumbled.

Almost any powder can generate static charges while tumbled. Thus,
that is not the reason why graphite is used, since it also can build
up static charges. To avoid static buildup they use water, the
powder is not yet completely dry while it is being tumbled or if it is,
some water is sprayed into the drum.  This also helps to break the
sharp edges and reduces dust to a great degree.

Graphite is used to make the powder free flowing and keep it that way,
to reduce caking. It also reduces the spark sensitivity of the BP,
basically against a static discharge, in this respect it does act as a
conductor and as a thermal "shield". Graphite reduces or better
prevents the powder from dusting while being handled. This affects the
spark sensitivity even more.

>measure as well as reducing caking that would otherwise occur from
>moisture absorbed from the air during storage.

This with the reduced dusting are the most important reasons.

>Bill

ArNO
    2

_______________________________________________________________________________
_____  _____  _____
|   |__|   |__|   |           A. Hahma
|                 |           Research Centre of the Defence Forces
|_________________|           Department of Chemistry
 |       .       |            Laboratory of Propellants and Explosives
 |   .       .   |            BOX 5
 |       .       |            SF-34111 LAKIALA
_|   .       .   |_           Tel. +31-492177
|        .        |
|                 |
|_________________|

From: sfaber@cbnewse.cb.att.com (steven.r.faber)
Newsgroups: rec.pyrotechnics
Subject: Re: Black Powder question
Message-ID: <1992Jan14.233318.22460@cbnewse.cb.att.com>
Date: 14 Jan 92 23:33:18 GMT

From article <1992Jan14.145400.25824@cetia.fr>, by philip@cetia.fr (Philip Peake):
> Firstly; excuse the dumb question (if it is dumb).
>
> I recently tried to make up a batch of Black Powder, and the results were
> not very good. The powder burns, but not very fast, and produces lots of
> sparks (red hot carbon articles ?)
>
> I used Potassium Nitrate from a garden centre, which is in
> a form resembling fine sugar, plus sulphur "dusting powder" (garden
> centre again - supposedly at least 98% pure) - very fine yellow
> powder, and finally crushed (wood) charcoal.
>
> The first attempt was simply to mix the ingredients - the burning
> rate was not impressive.
>
> I then tried taking very small amounts of this, and carefully grinding it to
> a fine powder with a mortar and pestle - it burns faster, but still
> not fast enough.
>
> I can only assume that a mechanical mixture is not sufficient, and that
> there must be some other means of forming a "tighter bond" between
> the components ?
>
> Any pointer are welcome.
>

This is a good question.   I imagine most people had the same problems
when starting out, I did.  There are netters with more experience in
this than me, but I'll try and summarize.

First you should not use charcoal briquetts since they contain clay.
Willow charcoal is best. You can make it yourself heating the wood in
a can with some holes punched.  Other wood will work - the less resins
the better.  Dusting sulfur is not a good idea, use purer stuff for
faster burning.
With those modifications you can hand grind a powder in a mortar &
pestle that is fast enough to make small bottle rockets with, if
you have patience & grind for 1/2 hr or so.  You may want to
modify the ratio's some and try 6-1-1.

For good gunpowder you should ball mill the ingredients in a tumbler
for a couple days for each and then for several more days mixed.
Some consider this to be somewhat dangerous and warn that the
tumbler should be bunkered well in case it all blows up.
It may help to tumble the saltpeter & charcoal together wet, dry it
and then tumble with the sulfur.
If it still is not fast enough you might want to recrystalize the
KNO3 and dry it first.

Your initial mix with store charcoal and dusting sulfur can
be good enough for rockets, if milled well.

There is another safer method to make powder that isn't quite as
good, but good enough for cannon powder, where you add alcohol
to a hot solution of the ingredients to precipitate out the KNO3.
Then press it and dry.

Steve

From: nreitzel@lonestar.utsa.edu (Norman L. Reitzel   )
Newsgroups: rec.pyrotechnics
Subject: Re: How to make BP questions
Keywords: powder black pyrotechnics explosives grinding manufacture
Message-ID: <1993Dec12.185948.849@ringer.cs.utsa.edu>
Date: 12 Dec 93 18:59:48 GMT

The thing about making black powder is the part about "thorough mixing".
It is difficult to accomplish, and it makes the difference between a powder
that is suitable for blackpowder arms, cannon, etc, and one that just sits
and fizzes and tosses sparks.

First, get the formula right.  It is 75% saltpeter (KNO3), 15% charcoal,
and 10% sulfur.  You can bump the charcoal up a bit at the expense of the
sulfur, but not by more than about 3%.  If you cut back on the saltpeter,
you _drastically_ reduce the strength of the powder.  For rockets, you
want less strength and more gas, so go with 65% saltpeter and 25% charcoal,
and keep the 10% sulfur.  This mix is good for about 3 lb. rockets.  For
smaller rockets, keep closer to the gunpowder formula.  A good grade of
charcoal is important.  If the stuff you plan on using has high ash, and
almost all "aquarium charcoals" or "activated charcoals" do, you may have
to tinker with increasing the charcoal percentage a few percent.

Second, you have to grind the ingredients.  You _cannot_ successfully
accomplish this with a mortar and pestile, except for a gram at a time.
Unless you are planning on making a cannon out of a soda straw, it's just
entirely impractical.  What you want is a ball mill, and guess what, they
are quite available at reasonable cost.  Go down to your local rock shop,
and buy a rock tumbler.  Then go to the local variety store, and buy a
couple of hundred marbles.  To grind an ingredient, you just put the
stuff in the tumbler with the marbles, put it in a garage or on your patio,
and start it up.  Let it grind for three or four days.  When you are done,
sift the marbles out and presto - instant fine grind.

To make a decent black powder, grind all three ingredients separately.
This is _important_ - if you dump them together and grind dry, you are just
asking to have your domicile vanish in a loud cloud of smoke.  Local fire
officials really look down on this, so grind separately.  Then, once you
have ground all three dry ingredients, mix them together, dump them back
into the tumbler, and add enough water to get a paste the consistancy of
thin mud - thin enough to pour, but just barely.  Then grind them again
for two or three days.  Check the stuff regularly, and do NOT let it dry
out.  I can't stress this enough.

When you are done wet grinding, dump the stuff out on a poly cutting board,
and fish out the marbles.  A strainer doesn't work well here; I just used
my fingers.  Wipe as much stuff off as possible, then wash them clean.
Let the wet mix dry undisturbed.  I live in South Texas where it's dry enough,
if you are unfortunate to live in the wetlands, you may need to put it where
it is warm.  Radiators are good, ovens are BAD, BAD, BAD.  Once the stuff is
dry, it is very hard and uniform.  Break it up by using a piece of canvas and
a wooden or plastic rolling pin - not a metal pin or a hammer.  Sift the
pieces to try to get a uniform size.  When the granules are the size you
want, put them in a plastic jar and add a little graphite - about a teaspoon
for every two cups of granules.  Shake _gently_ to coat the particles.  If
you don't want to coat them, then be sure to store them TIGHTLY sealed, as
they will slowly gather moisture and loose strength.

That's it.  You have class A black powder.

The dust you end up with when you break up the cake is called meal powder,
and is useful for pyrotechnics.  Or, you can dump it back into the wet
grind for your next batch.  On various occasions, I have made many batches
of the stuff, and used it with great success in both a 12 gauge black powder
shotgun and a Navy Arms .44 revolver.

Norm  (nreitzel@lonestar.utsa.edu)

Newsgroups: rec.pyrotechnics
From: John De Armond
Subject: Re: Ball Mills
Message-ID: <3wm5kvr@dixie.com>
Date: Wed, 30 Mar 94 07:50:57 GMT

tceisele@mtu.edu (Eisele) writes:

>And a point:  I personally wouldn't want to grind a mixture of oxidizer
>and fuel in one of these things.  You would be best off making two mills,
>one strictly for oxidizers, and one strictly for fuels.  *Never* grind
>oxidizer in your fuel mill, or vice versa, or you will have a very large,
>rather devastating pipe-bomb on your hands (nearly a kilogram of black
>powder, in a 1/4" wall thickness steel canister, is no joke)


One must mill the ingredients together to make gunpowder sooooo.
Don't do this one, kids.  A suitable mill for milling moist
gunpowder can be made from a chunk of 6 or 8" PVC pipe with a screw
flange cemented on each end.  Grind off any molding flash on the
flange so that it rolls smoothly.  strips of PVC cut from scrap
can be glued on the inside to make lifters.  Cap each end with a blind
plug.  Use lead ball/shot for the media.  Non-sparking and it is
heavy so the action is fairly rapid plus lead shot and ball is easy
to come by.  As Eisele says, mix the sizes.

Next, I'll describe an industrial ball mill we used at M&M mars to
grind chocolate/peanuts/sugar together to make the barrier creme
that is applied to a candy bar before the chocolate enrobing is applied.

These mills were vertical heavy wall stainless steel tanks about 3 ft
in diameter and 6 ft tall.  It was filled with several thousand pounds
of about .30 cal stainless steel balls.  A large spiral impeller
ran the length of the mill and was driven by a 150 hp motor.  The impeller
pulls the balls up, they spill over and fall back down along the sides.
This mill was a continuous process mill with the entrance on the bottom
and the exit on the top.  It milled the ingredients to creme consistency
on one pass through the thing which took about a minute.

This could be scaled appropriately for batch processing gunpowder by using
PVC pipe, a plastic impeller and lead shot.  An alternative impeller
might be a brass boat propeller.

John

Newsgroups: rec.pyrotechnics
From: "Norman Reitzel" <NormReitzel@swbell.keinspam.net>
Subject: Re: Milling BP. Wet or Dry?
Date: Wed, 17 Jan 2001 12:19:15 -0600 (CST)

On Wed, 17 Jan 2001 09:21:11 -0000, Pyrowork wrote:

> If you mill your BP wet, how do you get it out of your jar (its all stuck to
> the sides) and how do you remove from the milling media?

I mill more than slightly wet; I mill it the consistancy of baby food.  When
it's done, I use a rubber scraper to clean the drum, and then separate the
balls on 1/2" screen.  I spread the sludge in a think cake and dry.

When it's dry, I break off pieces and crack them into grains with a wooden
mallet, then sieve the pieces for size, and tumble for a few minutes with a
little graphite.

-- Norm

Newsgroups: rec.pyrotechnics
From: "Norman Reitzel" <NormReitzel@swbell.keinspam.net>
Subject: Re: BP? Little worried!
Date: Thu, 03 Aug 2000 14:28:45 -0500 (CDT)

I have been using glass marbles, and lately flint (chert) media for the last
20 years -- however...

I never mill mixed oxidizer/fuel dry.  Not ever.  I separately mill the
charcoal, sulfur, and nitrate.  When I mix them, I add enough water to make
it a rather moist slurry, then mill the mix.  I pour off the slurry through a
sieve onto flat sheets, then crush and tumble with graphite after they dry.

Also, I don't mix grinding media -- I have separate media for each chemical,
and for the mix.

-- Norm

On Thu, 3 Aug 2000 10:38:39 +0100, Justin Fielding wrote:

> Im using hardened lead, and yes, if they are glass marbles then it is
> extremely dangerous.  The ground glass which will inevitably get into the
> mixture acts as an abrasive and increases friction within the mix, I think
> some match heads have ground glass in them to aid ignition.
>
> Wow, well I was worried about doing it with my lead balls, and here you are
> getting on just fine with glass!
>
> <KillerQ97@aol.com> wrote in message news:8matab$1i2$1@nnrp1.deja.com...
> > Hello....
> >
> >
> >    I'm not insulting anyone, but aren't marbles dangerous with BP also?
> >
> >                    Just curious,
> >
> >                             Matt
> > --
> > **Nothing is dangerous.....If you have a long enough wick**
> >
> >
> > Sent via Deja.com http://www.deja.com/
> > Before you buy.
>
>