Black Match
Black match
is the simplest fuse for a home pyrotechnic to produce. It requires
only black powder, string, a binder, and a bit of a mess.
Black match can consist of one to five black powder coated strands,
allined in parallel or twisted together depending on the intended use.
Making black match can be as simple as submerging cotton string in a BP
slurry and allowing each strand to dry, but I will focus on a much
cleaner, faster, and more effecient method here.
The only composition required is black powder. There are however several other materials needed, all easily obtainable.
Supplies:
Black Powder
Cotton String (1 to 5 rolls as desired - inorganic string will not work)
Liquid Laundry Starch
Drill (with various size bits)
Several Long Nails (~ 3 inches long)
Large Plastic Funnel
Hot Glue Gun
Several Lengths of Dowel
Board
Building a
rig to make black match is the first step. It is important in order to
make a consistent burning fuse. If the fuse does not have a consistent
burn rate, it will not be suitable for use in most applications. This
machine will also allow fuse to be made very quickly, hundreds of feet
in minutes.
This design
pulls several strands of string down into a slurry of BP and liquid
starch. The black powder coats the string and is then pulled out of
holes small enough to remove excess BP. As the strands are pulled
through, they are twisted together to form one reliably burning fuse.
Between one and five strands may be used. A funnel is used to contain
the slurry because the shape is ideal to keep BP in contact with the
string even when it is running low. Using a container with a flat
bottom would require discarding much leftover BP that had passed to the
sides of the string.
The first step in building this black match machine is to drill a hole
in a plank to hold the funnel used. A 1 1/4" paddle bit ended up
working nicely for the funnel I purchased.
Next, a
hole is drilled through the side of the board into the area made for
the funnel. This will be for a nail to pass through the funnel, so the
hole made should be large enough for the nail to move freely.
The nail is then inserted and heated with a torch or lighter. The funnel is put in place and the hot nail pushed through it.
Hot glue fills all empty space from the underside.
A plug is inserted into the small opening of the cone and hot glued in place. A small piece of dowel works nicely as a plug.
Holes are
drilled into the top of the board to accommodate dowels. These will be
used for holding rolls of string. A hole must be made for each strand
desired in the black match. In this instance I have used two.
6" lengths of the dowels are then hot glued in place.
The final
step in building this black match machine is to drill holes for each
strand of string to pass through in the cone. These holes should be as
small as they can be before the string will not fit through. The small
holes will remove excess BP and let it drain back down to the bottom of
the funnel.
The holes must be positioned to allow the string to run through them,
under the nail, then back out the hole on the opposite side of the
funnel.
The machine
is now complete. To prepare it for use, set each roll of string on the
dowel made for it, and thread each strand through the funnel. When
ready, it will look like this:
Black
powder is then made into a slurry using liquid laundry starch to wet
it. When enough starch has been used to turn the powder into a soft
clay, it is enough to bind the composition. Water can be used to wet
the mix the rest of the way. It should be wet to the consistency of
thin yogurt.
The slurry
is then poured into the funnel. The strings may then be pulled through.
This should leave them coated in black powder. If areas remain uncoated
on the strands, it may be a result of the composition being to thick,
or the strings being pulled to quickly. It helps to tie the strands
together to more evenly pull them. As they are pulled, twist the lines
together. This will create a multistrand fuse that will be more
reliable than one strand alone.
The black
match is pulled straight back from the machine by a person walking
backwards. If the distance is great enough, by the time there is no
more room to walk backwards the fuse will be dry enough to coil. The
individual making the black match then walks forward coiling the black
match by hand. Once it is coiled all the way up to the machine, the
roll is cut off and set out to dry in the sun. This process may be
repeated until the black powder has all been expended.
Here are several rolls drying. They are the result of less than five minutes of work and are together about two hundred feet:
The last
step that must be taken is to do a test burn of the black match. A foot
is marked off on a board and a strand of the fuse is run across it.
Using a video camera or a stopwatch, record the amount of time it takes
to burn from one mark to the other. Be sure it is an even and steady
burn with no changes in speed. Divide the time it took for the fuse to
burn by 12 and the resulting number will be the burn rate per inch.
Write the number down on a piece of paper and keep it in a bag with the
fuse for future reference.
That is all there is to it. Be sure to check out the Safety and Legal page before building any fireworks.
