Guide to Fuses and Fusing

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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.  Itís 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

 

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. 

BURNING QUICK MATCH

 

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.

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.

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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