Homemade Fireworks for the Pyro Purist
CAVEAT
If you are a common-sense-challenged, not-the-sharpest-knife-in-the-drawer,
clumsy type person, please be aware that all the safety tips I could give you
regarding the activities described on this page will not do you a bit of good.
You would discover something I overlooked. And so you will at best only get
badly burned, poison yourself, singe your eyebrows, barbecue your fingers
or maybe even blow your garage door off. Space does not allow me to put all
the things you should never do. You will be dealing with mixtures that flash
or explode at the first opportunity you give them, intentionally or otherwise.
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USE GOOD JUDGEMENT
Never sell or give away any modified or homemade pieces. Make only as much
as you will shoot and shoot them all off on the holiday you made them for.
Find a location where aerial fragments can land safely. Be prepared for
fires. Start with consumer pieces and shoot homemade pieces in between those.
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SKYROCKETS MADE FROM MODEL ROCKET MOTORS
This makes a good report skyrocket. Loud booms high in the sky on the
Fourth of July and New Year's Eve don't usually create alarm. And rockets
give plenty of warning of their impending report. The only drawback to these
is that Estes motors are expensive.
Sketch of a simple report skyrocket.
The simplest skyrocket is based on a B6-2 (only) model rocket motor. Report
mix goes in the space above the parachute-ejection charge. The motors require
a 1/2" plug. You can make plugs using a 1/2" plug cutter in a drill press and
thin plywood from paddle-ball (ball on a rubber band) paddles. Look in stores
selling party items. Fill the top with report mix of your own or from consumer
fireworks, leaving 1/8" for the plug. Glue the plug 1/16" down inside the
motor. Guide sticks should be 3/16" or 1/4" square and 18" long.
Cross-section of a B6-2 motor.
The white part at the right is clay over the dark chute-ejection charge.
The grey is the chute delay (2 sec.). The large dark area is the propellant.
The white at the bottom is the clay nozzle.
On the day you intend to shoot them, use a safety pin to scratch the core
to get past the safety coating or use a 7/64" drill bit in your fingers. This
will allow fuse to light the motor.
If you use Phantom Fireworks or TNT Fireworks fuse, hold it in with a small
wad of paper. The end must touch the propellant. Red pyro (safety, Bickford,
cannon) fuse will stay in. TNT's fuse is better than Phantom's.
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MORTAR SHELLS
Mortars are a good way to put loud booms high in the air where they will
not be mistaken for gunshots. Good tubes to use are 3" long, 5/8" inside
diameter, just under 3/4" outside diameter, spiral-wound. Cut these in half.
Use a 5/8" plug cutter to cut wood disks from paddle-ball paddles. A 1" long
pyro fuse, 1" long TNT fuse or 1 & 3/16" Phantom fuse gives a proper delay.
You must put tape around the fuse so that the lift charge lights only the tip
of the fuse. Use a 1" x 1" length of duct tape and drill a 5/32" hole if
using pyro fuse. Drill a 1/8" hole if using TNT fuse.
Sketch of the mortar shell.
It is very important to put glue on the inside at the bottom disk. Three
level 1/8 tsp (25 grains) of Gorski Gourmet black powder (see printable web
page) works well for a lift charge. Or use the lift charge from consumer
fireworks.
Sketch of the base for a mortar.
A 24" length of 3/4" copper pipe fits onto the base. The base is seated
on a 3/8" steel rod pushed into the ground. A 3/8" lift charge hole needs
to be 1 & 7/8" deep. A 7/16" lift charge hole needs to be 1 & 1/4" deep.
You can also use the steel-tube handle from some brooms, the kind that are
25/32" inside diameter and just over 27/32" outside diameter. The mortar base
will have to be turned on the lathe to match this size tube.
Steel-tube mortar and aluminum base on a 3/8" rod.
A mortar shell using the full-length tube.
This will be much louder because it is double the size plus the composition
is ignited from the center. Shoot these in rural not annoyed or alarmed by
loud booms.
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The simplest way to lift the mortar shells is in Phantom Blue Streak
rockets. Open the red tissue, pull the paper wad out if there is one and dump
the stars and "buzzing-bee" fuses into a jar. Put 1/8 tsp black powder and
the mortar shell in. (If the top is too small, cut it open so it will fit.)
The bottom plug for these shells does not need to be glued on the inside.
And there does not need to be a fuse. Just put a piece of masking tape over
the fuse hole before putting the flash mix in. Glue the top disk in. Drop
or work the shell into the rocket and put tape over the top.
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GOOD CONSUMER ROCKETS
The Phantom Fireworks Display Shell rocket.
These have a wide upper body section that is empty. Remove it for less air
drag. They have a good report plus a good display. $2.50 each, two for one.
The TNT Big Bomb skyrocket.
These have a nice report and display. And TNT fuse is very good.
Stars(balls), "flying fish"(fuses) & burst charge.
This is the standard payload for many consumer skyrockets. Phantom
Fireworks Blue Streak skyrockets have about 40 grains of "buzzing bee" fuses,
stars and burst charge. They cost $.83, two for one.
Red pyro (safety, cannon, Bickford) fuse fire spit.
Green Phantom/Chinese fuse fire spit.
Green TNT/Chinese fuse fire spit.
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ADD A BOOM
Adding a boom or a second boom to a skyrocket.
Be sure that the rocket's exhaust blast will light the boomer fuse. And be
sure that the boomer fuse is not accidently lit first with the lighter!
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FUSE PRIMER
Weigh some black powder and put it in a mortar and pestle. Weigh 6% of the
black powder in dextrin and add it in. For instance, 9.4 grains of black
powder requires .6 grains of dextrin. Mix it dry with an artist's bristle
brush. Grind with the pestle. Drip in a couple drops of water. Stir with a
toothpick. Dip the ends of the fuses into the slurry or use a brush to paint
the slurry onto the ends of the fuses. It must dry completely before use.
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SLOW MATCH
Making slow-match fuse.
Cotton string is soaked in a solution of 1/2 tsp potassium nitrate in 1/4
cup of warm water. Let the string soak up the solution and then allow the
water to evaporate away. Slow match must hang freely, not touching anything.
It burns at about 25 seconds per inch, depending on the string used. Use fuse
primer to join slow match to pyro fuse.
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LIGHTING FIREWORKS
Use a barbecue lighter to light fuses, but keep the end of the lighter out
of the fuse's fire spit. The spark will not light the butane if the end gets
coated with chalky-white fuse-sparks residue.
The Coleman Wind Resistant lighter.
A good lighter for fireworks and the best for the pickle jar jet engine.
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MAKING GOOD PYRO CHARCOAL
CHARCOAL made from "mixed hardwoods" is sold by pyro suppliers, but charcoal
made from balsa is better, cleaner and easy to make.
A propane camp stove and stainless flan mold.
There is a 1/8" hole in the top where the smoke exits. When the smoke
stops, the charcoal is ready.
Balsa charcoal made in the flan mold.
Balsa releases the least tar. The thinner the wood pieces, the faster they
will finish charring. Pine will produce thick, black tar which will stink,
bubble out, drip down the side and maybe even catch fire.
Pine charcoal made from wide craft sticks.
After the wood has charred completely, put it in a large freezer bag, work
all the air out, seal it and break up the sheets with your fingers into small
pieces before milling.
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BLACK POWDER CHEMICALS
SULFUR can be found as sulfur flour or sublimed sulfur in drug and farm
stores. Flowers of sulfur has some acid and its use is discouraged.
POTASSIUM NITRATE is found as SPECTRACIDE brand Tree Stump Remover (only!).
Chemicals, mortar and pestle, rock tumbler, etc.
Red gum is not shown in photo. The rock tumbler is a ball mill. The milling
media are 5/8" steel balls (MSC #00073312). Plastic cups are good for weighing
powders as well as for holding pulverized and weighed powders temporarily.
Ball-milling all three ingredients together for six hours makes the best
black powder.
Ball-milled potassium perchlorate and a hair.
Other useful items.
The stainless collander has 3/32" holes, ideal for "corning" the black
powder "mud" into rice size for proper drying. Corning is essential so that
the mix dries quickly or else the potassium nitrate will crystallize out.
Work the "mud" through with a plastic putty knife. The deep-fryer basket is
used to separate the 5/8" ball mill media from the milled powders. The
measuring glass is marked in teaspoons tablespoons, milliliters and ounces up
to 4 oz. Powders that have clumped, like potassium nitrate, percholorate,
sulfur, etc., should be worked through a kitchen strainer using a pestle
before ball-milling.
The Bella Cucina Rocket(!) Blending Set.
The perfect blade mill for pyros. There are extra cups and two blade types.
The bottoms, with the blades, even have a rubber gasket so charcoal can't blow
out! But blade milling is only for a first milling. Ball-milling is essential.
Three ways to weigh chemicals.
The reloader's scale is the most accurate. The letter scale needs cups to
hold the powders and is not accurate. The digital scale is the easiest to use.
Square plastic jar modifed for tumble-mixing.
The drill/screwdriver is set on screwdriver speed.
MAKE GORSKI GOURMET BLACK POWDER (printable).
The best black powder for the must-do-everything-myself perfectionist pyro.
Grains of FFg(top), FFFFg(right) and table salt.
Grains of black powder the size of table salt work best. Finer, coarser or
mixed grains give 4/5 the power of all-FFFFg-size grains.
Reliable pyro chemicals source.
Skylighter has excellent stuff, lots of online info, books about everything
pyro and their phone ordering (real humans!) is streamlined (1-540-338-3877).
americanpyrosupply.com has a very slow web site and no phone ordering, buyer
beware! www.cheap-chemicals.com is the most expensive source!
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REPORT MIX
potassium perchlorate (NEVER chlorate!) 319 grains (20.67 gms)
black pyro aluminum powder 137 grains (8.88 gms)
WARNING: A 50-gram amount, just TWO batches, of UNCONFINED mix will DETONATE
if accidentally ignited! Mix ONLY one small batch at a time!!!
Measure using a reloader's powder scale. With the rounded end of a broom
handle cut off to a convenient length, work the perchlorate through a kitchen
strainer because it tends to clump. Then, if you want the very best results,
ball mill the perc for six hours. Use the perc right after ball-milling or
else it will clump back again. If you do not have a ball mill, use a blade-
type coffee grinder to make the powder as fine as possible. (With a blade
mill, you do not have to work the perc through a strainer first.)
It isn't necessary to do anything to the aluminum. But if it appears to
be clumping, work it through a fine strainer with an artist's bristle brush.
The two parts of the composition are perfectly safe UNTIL mixed! Plus,
this particular mix is inherently safe.
The accepted way of mixing is to put the composition onto a 2 foot square
of newspaper. Raise each corner in turn so that the mix folds over onto
itself over and over until well mixed. Break up any clods with the artist's
bristle brush. You can make a "marionette cross" to simplify this procedure.
But we mix using a plastic jar with a copper screen crosswise inside it
rolling around inside the rubber ball mill drum in the rock tumbler for a few
minutes. The composition goes thru the screen twice on every drum rotation.
After the mix looks evenly gray with no lumps, spoon it into one piece at
a time using a funnel. Push a plug down 1/16" inside the piece and put glue
around the plug at the rocket or mortar shell wall.
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ORDERING SUPPLIES
If you don't want to set off red flags, you have to order supplies from at
least three different vendors and have the orders sent to three different
addresses and names. None will send oxidizer and aluminum to the same address,
even on orders weeks apart, unless you have the BATF papers. So order "perc"
(perchlorate) from one supplier, pyro aluminum from another and everything
else from a third. Use local supplies as much as possible. But the very best
aluminum powders, German black and American dark, are red flags waving. And
there are limits on how much of some pyro chemicals you can order per year.
Stuff to make your own tubes.
Tubes can be homemade by rolling an index card around any 5/8" form (bolts
shown here), taping it to itself, then gluing gummed reinforced paper tape
wiped with a wet paper towel over the index card tube.
ALUMINUM POWDER OPTIONS
Etch-a-Sketch toy aluminum powder in a microscope.
Mohawk M380-4361 aluminum powder in a microscope.
Used for metalizing wooden furniture and frames. It is stearin-coated.
Pyro aluminum powder in a microscope.
All photos are at the same 100X magnification.
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SCRATCH-BUILT SKYROCKETS
The homemade skyrocket.
Sketch of the homemade skyrocket.
Sketch of the special tooling.
Parts of the rocket.
Equipment used, minus a 3-lb. sledge.
Skyrockets made from scratch require parallel-wound (only) motor tubes,
potassium nitrate, powdered sugar, fuses, wooden nozzles, wooden disks,
sheet-metal nozzle throats and guide sticks.
Parts per rocket:
motor tube, 1" O.D., 3/4" I.D., 3 & 1/2" long (7" cut in half)
(Suppliers call these either "parallel" or "convolute" wound.)
guide stick, 3/16" to 1/4" square, 18" long
wood nozzle, 3/4" O.D. dowel, 5/8" long, drilled 3/16"
2 thin plywood disks, 3/4" O.D.
steel nozzle throat, 16 or 18 ga., 3/4" O.D., drilled 3/16" in center
Tooling:
1" O.D. centering tool to fit over 3/4" wood nozzle for a 3/16" drill bit
3/4" O.D. by 6" long steel ramming rod
3/4" O.D. by 3/4" long aluminum end plug, tapped 1/4"-20 one end
1/4"-20 bolt for removing end plug
1" I.D. by 3 & 1/2" long pipe nipple cut one side with hacksaw
(be sure that the motor tubes will fit inside BEFORE purchasing)
3 hose clamps to fit over pipe nipple
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Weigh out 65 gms of potassium nitrate and 35 gms of powdered sugar. Be
sure they flow freely. If they are clumping, work them through a fine tea
strainer using a broom handle pestle. They must be mixed well. A square
plastic jar rotated by electric screwdriver works great.
Square plastic jar modifed for mixing powders.
Saw the cardboard tubes in half. Push the tube into the split pipe and
tighten the hose clamps.
Insert the ramming plug into the factory-cut end of the tube so that the
1/4"-20 hole is down. Seat this end on scrap hardwood that is on a very
solid workbench or is on a concrete block on the workshop floor.
Using a funnel, pour one level teaspoon (only!) of propellant mix into the
tube. Using the ram and a 3-lb. hand sledge, compress the propellant with
several hard blows. Stop when you see that the ram is no longer advancing.
Add more propellant by level teaspoons (only!) and continue until there is
2 inches of propellant.
Loosen the hose clamps and push the motor out. Put the 1/4"-20 bolt into
the end plug and pull it out. Tap the motor to remove loose powder.
Put the drill guide over a 3/4"-diameter dowel cut to 5/8" long. Drill
through the center using a 3/16" bit to make the wooden part of the nozzle.
Turn the rocket motor nozzle-end-up. Put the steel throat (see below) down
squarely on the propellant. Put white glue around the nozzle and inside the
motor tube where the nozzle will go. Twist the nozzle down into the motor
tube, firmly against the steel throat so that the steel throat is hard against
the propellant and the wood nozzle is hard against the steel throat. Stand
the motor nozzle-end-up and allow the glue to dry overnight.
Measure how deep the top of the propellant is from the top of the motor tube
and mark it on the outside of the tube.
Push a wooden disk down firmly onto the top of the propellant. Put glue
around the disk at the tube wall and let this glue dry overnight.
With the rocket on the drill press nozzle up, use a 3/16" drill bit to drill
down EXACTLY 1 & 5/8" into the propellant to form the hollow core. See your
mark on the outside to know how far to go. DO NOT drill to the central disk!
Drill for the fuse you will use through the side of the tube so that the
drill bit comes out just into the propellant and just under the central disk
as shown in the sketch. Cut the fuse at an angle. Twist the fuse into the
hole. Measure from the TOP of the tube to the top of the wooden disk and mark
this point on the tube.
With the materials given here, a delay, 1" of pyro fuse, 1" of TNT fuse or
1 & 3/16" of Phantom fuse works well. Drill another hole above the central
wooden disk such that the fuse, which is outside the tube, re-enters the tube
above the disk. Put a dab of glue on the fuse at both holes.
Add report mix or black powder burst charge and display mix to the payload
section. For report mix, plug with a wooden disc and glue. For display mix
(stars, "flying fish" fuses and burst charge) just put tape over the top.
Put tape over the bottom until ready to launch them to keep moisture out.
You can tape or glue a guide stick on. (Use a rubber band to hold the stick
temporarily while glue dries overnight.)
On the day the rockets are to be launched, put a length of fuse up into the
core and wedge a small wad of tissue in the nozzle to hold it.
If using locally-obtained chemicals, make a test rocket with sand to find
out the height the rocket will go and therefore what delay is required. If
more thrust is needed, make the propellant longer and drill the core deeper,
but always stop 3/8" short of the central wooden disk.
Use a cabinetmaker's 3/4" plug cutter to cut plugs from thin ply.
The "washers" are made from sheet metal using a Roper-Whitney punch. First,
dimple the sheet metal with the 3/16" punch. Then use a compass to mark the
3/4" outline. Now punch the hole and cut the nozzle thoat out with tin snips.
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OTHER GOOD BOOMS:
Black powder alone does not make a loud boom in a shell casing. But it will
if fired in a 1/2"-bore cannon. The bore should be about 12" to 18" long.
With Goex FFFFG black powder, no paper or cloth wad is necessary.
Steel black powder cannon with 3/4" bore.
This took a long drill bit and a long time to drill. The barrel must be in
a lathe chuck and the drill bit in the tailstock so that the drill bit will
follow the axis of rotation down the center. This cannon was used with a
chronograph for comparing FFg Goex, FFFFg Goex, Pyrodex (the fake stuff) and
several of our homemade black powders.
Galvanized pipe black powder mortar.
This noisemaker has a barrel made of pipe and is ignited by a percussion
cap made for black powder guns. The #11 cap fits on a 5/32" roll pin. The
hammer hits the cap when the lanyard is pulled.
A "carbide" (acetylene) cannon also makes a very loud, very sharp report.
Calcium carbide creates acetylene when dropped into water. The acetylene must
mix with the right amount of air. The cannoneer must wear hearing protectors.