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Proper fusing of fireworks and
knowing which type of fuse to use is one of the most crucial parts of
a fireworks display. Though
using fuse seems to be easy, the consequences of careless or
incorrect fusing can result entire sections of a display firing
prematurely or not at all, neither of which you want to happen.
It’s terribly embarrassing to have a rack of shells, a
portion of repeaters, or a letter of a set piece fail to fire in
front of friends and family, all because of something simple like a
fuse not being connected right.
Below you will learn about several types of fuse, how they are
made, their pros and cons, and how to use each one effectively.
All of the methods of ignition listed below have been tested
and used by me personally time and time again, and I find them to be
extremely reliable.
Visco
| Visco fuse, also
known as "safety fuse", "cannon fuse", "slow
visco", or just "fuse", is the most commonly-used and
well-known type of fuse in fireworks. It consists of a multiple
layers of threads woven around a core of black powder in such a
fashion that the threads don't unravel. Some types of visco
have been coated in a nitrocellulose lacquer solution to make it
waterproof. It is available in red, green, and
red/white/blue striped varieties, and in several different diameters
- the larger ones being more reliable.
Visco is one of
the slowest-burning fuses, transmitting fire at about 0.4
inches/second (or, as it is more commonly measured, 2.5 seconds/inch
or 30 seconds/foot). This makes it ideal for creating delays -
all consumer fireworks in the United States have a visco fuse, which
allows the person lighting the device to retreat to a safe distance
before it ignites. Pyros who put on 1.4G fireworks displays
commonly use it on cake boards to control the timing between the
sequential ignition of cakes (e.g., a 1-foot piece of visco between
two cakes would give a 30 second delay between ignitions, allowing
the second cake the begin firing before the first finishes). It
can also be used in shell racks to create a slow-paced firing
sequence, as the 1-2 inch gap between adjacent mortars in a rack
would allow for a 3-5 second delay between shell launches and
subsequent bursts. |
BURNING
VISCO
 |
Visco fuse is sold
at most pyrotechnic supply companies, including Skylighter,
Firefox,
and Cannonfuse.com (all of which I have personally purchased from).
It can also be found in some gun shops under the name "cannon
fuse" (it's used by model cannon enthusiasts), but the price per
foot is typically much higher. As mentioned previously, I
prefer the thickest visco available (typically 3 mm in diameter) that
has a waterproof coating - this makes it resistant to drizzle and
errant sparks.
Fast Visco
| As the name
implies, fast visco is a variant of standard visco fuse that burns at
a much faster pace - typically 4 inches second (or 3 seconds/foot);
ten times the rate as regular ("slow") visco. The
only type of consumer firework that uses fast visco is the aerial
shell, which requires a fast fuse so that the overall burn time falls
within the required 3-6 second parameter for consumer fireworks in
the US.
Fast visco mostly
finds use in finales (or just a quickly-paced portion of a show),
where the pyro wishes to ignite a number of fireworks in rapid
succession. For instance, a board of four cakes placed one foot
apart (measuring from fuse-to-fuse) with quick visco connected to
each cakes's main fuse will, when lit, ignite each cake within 15
seconds of each other. A 2-foot long mortar rack containing
shells connected to one length of quick visco will result in each
shell bursting within about a second of the next one, creating a
fast-paced, exciting display.
Like regular
visco, fast visco can be found at most pyro suppliers, including the
ones listed above. Though the fast visco seen on shells is
usually green, it is usually sold in yellow so as not to be confused
with slow visco. |
BURNING FAST
VISCO
 |
Sticky Match
| Sticky match is
made of two strips of clear cellophane tape containing a thin trail
of finely-ground black powder. One of the tape strips is wider
than the other, making the outer edges of one side of the fuse
sticky. Sticky match is available in two varieties: fast (burns
at 80-100 feet/second), and slow (burns at 1-2 feet/second).
The fast variety is used where near-instantaneous ignition of
multiple devices is required - particularly with lance work in the
world of 1.3G fireworks. Unlike quick match, sticky match can
be quickly and easily attached to lances (the black powder trail is
centered over the lance, then the sticky edges are folded down over
the body), and leaves behind almost no residue when it burns.
It can also be used in 1.4G finale boards, but since the thin tape
layer is all that protects the black powder grains from sparks, it is
very prone to accidental ignition from falling sparks or nearby
fuses. |
BURNING
STICKY MATCH
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Quick Match
|
Quick match is an
extremely rapid-burning fuse mostly used in 1.3G fireworks to ignite
clusters of fireworks at nearly the same instant. It consists
of a loose-fitting paper tube (about 1/4 inch in diameter)
surrounding a cotton string that has been impregnated with a black
powder solution. When the string (known as black match, without
the paper tube) burns, the paper tube forces the large volume of hot
gas and sparks forward, igniting the next section of match which
creates more gas/sparks, and so on. This causes the quick match
to burn at upwards of 100 feet per second, which allows it be used to
set off rocket volleys, finale shell chains, candle racks, or other
devices separated by a long distance.
In the US, quick
match is considered a 1.3G item and thus cannot be purchased without
a BATFE permit. If one has such a permit, it can be purchased
from dealers like Skylighter
and Victory (though Skylighter will not
ship it). Quick match can also be made for your own personal
use.
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BURNING
QUICK MATCH
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Less-common
fuse types
The following is a
brief description of some of the less commonly used types of fuse in
the world of fireworks
Paper Fuse
| Also known has
"firecracker fuse", paper fuse is seen almost exclusively
in strands of firecrackers. Likely the earliest type of fuse,
it is made a thin trail of black powder wrapped with a thin tissue
paper. Most people who have lit firecrackers (or unraveled them
to scavenge the fuse) know that this type of fuse is rather
unreliable; prone to burning at wildly varying rates and
spontaneously sputtering out (and sometimes restarting).
However, it can be placed in a paper tube to make quick match.
Available from Cannonfuse.com and
Skylighter. |
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Time Fuse
| This type of fuse
is used in aerial shells as a time delay between the lift charge and
burst charge. Its multiple layers of twine, paper, and asphalt
make it nearly impossible to ignite from the outside (even from an
end, since the asphalt often melts and seals it off before the powder
can ignite), meaning that shell makers must cut into it and insert a
short piece of black match fuse sideways in order to ensure ignition
of the time fuse's black powder core. Time fuse burns at about
3 seconds/inch. Available from Cannonfuse.com and
Skylighter. |
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Special
Effects Fuse
| Special effects
fuse includes flying fish fuse, falling leaves fuse, and strobe fuse,
and are most often cut up into short pieces and used as shell inserts
(along with or in place of stars) rather than as means of
transmitting fire between devices. Flying fish fuse creates a
rocket-like effect as it burns, enabling small pieces of itself to
fly randomly across the sky (producing the well-known "flying
fish" effect). Falling leaves fuse produces gentle,
long-lasting sparks. Strobe fuse creates bright strobe pulses
as it burns, much like consumer strobe pots. All specialty
fuses are available in a variety of different colors from Cannonfuse.com
and Skylighter. |
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