Fireworks Making 101

September 11, 2017 | Author: htmagic | Category: Fireworks, Rocket, Shell (Projectile), Ballistics, Nature
Share Embed Donate


Short Description

Fireworks manufacturing 101. Construction details for common fireworks....

Description

Fireworks Making 101

Fireworks Making 101

Skylighter, Inc. PO Box 480 Round Hill, VA 20142-0480 USA

© Copyright 2012 by Skylighter, Inc. All Rights Reserved. No part of this book may be reproduced in any form or by any means, without permission in writing from the publisher.

Skylighter.com - 2 -

Fireworks Making 101

Introduction This book is designed to give you an overview of how the most popular types of fireworks are made: stars, aerial shells, and rockets. This little book is by no means exhaustive. But it will give you a fairly complete presentation of most of the current types of stars, shells and rockets commonly used in fireworks today, and a brief overview of how each type is made. The sections are designed in “building-block” fashion. First you learn about stars and other devices used inside aerial shells. Next you’ll see a section on different types of and construction alternatives for aerial shells. And finally, the chapter on rockets shows you rocket engines and how shells can be used as rocket “headings.” There are many, many kinds of fireworks you can make, other than the ones shown here. But these are the ones most requested by our customers at Skylighter. So, this is a good starting point for learning to make aerial shells and rockets and just what goes into them. All of the chapters in this book were written by Ned Gorski, and we are indebted to him for his thoroughness and clarity in their presentation. We welcome your input and suggestions for changes and corrections. Just address them to [email protected]

Free Fireworks Making Plans Fireworks Making 101 is the beginning of 75-part fireworks-making course that you can get online from Skylighter. Just click here to sign up for detailed plans on making every kind of fireworks you can imagine. The plans and projects are free. There’s no catch, no credit card required. When you sign up, you’ll receive an exciting new fireworks-making project every 3-5 days by email. Each one gives you a detailed, step-by-step tutorial that shows you exactly how to make each type of firework. Tutorials are all instantly downloadable and contain color photos, detailed diagrams, and even videos to show you exactly what to do. There is no charge for the tutorials, and you can unsubscribe to them anytime you want. You are not obligated to buy anything, although we do hope you will consider Skylighter when you need fireworks chemicals, fuse, tubes, tools, and other supplies. Skylighter.com - 3 -

Fireworks Making 101

Start learning to make fireworks right now, by clicking here. Thank you. Harry Gilliam Chief Cook & Bottlewasher Skylighter, Inc.

Skylighter.com - 4 -

Fireworks Making 101

Contents Introduction.............................................................................. 3 Contents ................................................................................... 5 Stars & Shell Inserts................................................................ 7 Introduction ................................................................................................ 7 Fireworks Stars........................................................................................ 10 Star Effects .............................................................................................. 11 Star Manufacturing Processes................................................................. 12 Cut Stars.................................................................................................. 12 Pumped Stars .......................................................................................... 15 Rolled Stars ............................................................................................. 18 Garnitures Wrapped in Paper .................................................................. 19 Conclusion ............................................................................................... 23

Aerial Shells ........................................................................... 25 Ways of Launching Shells........................................................................ 27 Shells Launched on Rockets ................................................................... 27 Shells Fired from Mortars......................................................................... 28 Parts of a Shell ........................................................................................ 29 Size Does Matter ..................................................................................... 30 Paper or Plastic? ..................................................................................... 30 Balls or Cans? ......................................................................................... 31 Welcome to Aerial Shells. Will that Be a Single, Double, or Triple?......... 32 Garnitures ................................................................................................ 33 An Overall Shell Description .................................................................... 33

Fireworks Rockets................................................................. 36 There are Rockets and Then There are Rockets..................................... 37 Fireworks Rockets in Depth ..................................................................... 40 Anatomy of a Fireworks Rocket ............................................................... 42 Size Does Matter ..................................................................................... 43 Traditional Fireworks Rocket Size Nomenclature .................................... 44 Rocket Motor Sizes and Designations ..................................................... 45 Types of Fuel Used in Fireworks Rockets................................................ 46 Overview of Fireworks Rocket Construction Methods ............................. 48 Nozzled versus Nozzleless Motors .......................................................... 49 Methods of Consolidating Rocket Fuel .................................................... 50 Means of Stabilizing a Rocket.................................................................. 51 Rocket Heading Types............................................................................. 52 Summary of A Rocket’s Nomenclature .................................................... 52

Skylighter.com - 5 -

Fireworks Making 101

Skylighter.com - 6 -

Chapter 1 – Stars & Shell Inserts

1 Stars & Shell Inserts

Introduction “Garnitures.” Kind of an old-fashioned word, not heard very often in conversation. But, as used to describe the class of fireworks components we are about to look at, I’ll be darned if I can find a better word. From “Traditional Cylinder Shell Construction, Part I” by A. Fulcanelli, found in Pyrotechnica IX: “Garnitures. The general term “garniture” refers to the contents of a shell (e.g., cut stars, pumped comets, serpents, whistles, reports, tourbillions; essentially anything that will fit in a shell.”

Skylighter.com - 7 -

Chapter 1 – Stars & Shell Inserts

Pumped-Star Garnitures Filling a Shell-Casing Hemisphere And, from the dictionary, the root of the word “garniture” lies in the term “garnish,” which is defined as “to furnish with beautifying details.” To furnish with beautifying details. Doesn’t that sound lovely? That’s exactly what we are asking of our various types of garnitures. There are basically two “sub-assemblies” of a fireworks shell. The first assembly includes the shell leader-fuse, the lift powder, the time fuse, the shell casing, and the burst powder. That whole integrated construct, though, serves one purpose– that of getting the second assembly, the garnitures, up into the air and ignited. Without the garnitures, the shell wouldn’t really serve any purpose. So garnitures refer to the contents of a shell, whether it is used as an aerial shell, a rocket heading, or as an insert in another shell. (In the case of a shell insert to be used inside a larger shell, I suppose the contents of that smaller shell could be referred to as “garnitures of garnitures,” or maybe garnitures squared.) The contents of fireworks mines, and other ground devices–such as cakes, roman candles, and single-shot comets–would also be called garnitures.

Skylighter.com - 8 -

Chapter 1 – Stars & Shell Inserts

Fireworks Stars in a Mine/Mortar Cross Section Interestingly, as a slight contrast to the definition of garnitures as the contents of a device, many of these components can be attached to the outside of a shell to act as what the Japanese call “Kyoku-do,” rising effects. Large stars attached to the outside of a shell will create a rising tail as the shell ascends skyward. These large rising tails can also be created for rockets by attaching a large comet to the exterior of the rocket motor or heading, to be ignited when the rocket launches. Scatter-stars assemblies, described toward the end of this essay, may be attached in pairs, Lincoln-Log fashion, on the exterior of a shell, with graduated time-fuse timings. As the shell rises, these stars will spit out to the side, perpendicular to the shell’s trajectory. Small star shells or reports can be attached to a shell to create “ascending small flowers” or “ascending thunder.” Or attaching a whistle can augment a shell’s ascent. Although stars are typically the first components that might come to mind as the contents of a shell, when you stop and think about it there are actually many different varieties of shell inserts. It is an overview of these varieties that I’ll be presenting here. Information on how to actually make the different kinds of garnitures is the subject of separate projects.

Skylighter.com - 9 -

Chapter 1 – Stars & Shell Inserts Taken together, all of these devices comprise the largest and most diverse class of components in fireworks making. A very wide range of construction techniques and fireworks effects is included in this category. The broad category of garnitures can be subdivided into two parts–stars and inserts. The effects, construction, and manufacturing methods of these two categories are quite different. Generally, fireworks stars are increments of pyrotechnic composition bound into pellets. Inserts are bound in paper tubes, paper sheets, or other types of casings. Inserts may themselves contain stars.

Fireworks Stars When we picture the traditional “flower” display of an aerial shell, the individual points of light and trails of sparks are created by “stars,”–pyrotechnic composition which has been bound into solid pellets. Simple firework stars are like small charcoal briquettes, with the composition bound together using a binder such as dextrin, some other starch, or a gum. I remember the first time I dissected a commercial, consumer fireworks shell 20 years ago (something which has to be done very carefully). Inside the shell I found what looked like seeds coated with black powder–black-powder coated, rice-hull burst-powder I later learned. And there were small chunks of “stuff” which I described as small charcoal briquettes in my notebook. This was my first experience with fireworks stars.

Aerial Shell Star Bursts with and without Spark Tails

Skylighter.com - 10 -

Chapter 1 – Stars & Shell Inserts

Star Effects Virtually an endless array of visual and audible effects can be produced by fireworks stars. Most of these effects result from the different compositions used to make the stars. You’ll hear star formulas described as “charcoal streamer star” or “color star” or “silver-spark streamer” or “strobe star,” etc. These different effects are created from the different chemicals in the composition formulas. Other star effects are the result of different processes used to make the stars: pumped stars, cut stars, box stars, rolled stars, go-getter stars, etc. Many different effects are dependent on the method that is used to make the stars. The star effects listed below are created simply from different consolidated compositions, with no tubes or wrappings on them. (Composition-filled tube effects will be described in a minute): 

Single color, non-tailed star, in a wide variety of colors



Colored star which leaves a spark tail behind it



Color changing star



Charcoal star which leaves a trail of orange, charcoal sparks



Star which leaves silver or yellow metal spark tails behind it



Unique metal-fueled stars like zinc-granite stars, and electric-spreader stars



Firefly stars



Daytime smoke stars



Crackling stars



Strobe stars



Very fast burning stars



Slow burning stars



Silver or gold glitter stars



Small stars which produce a flower with many points of light



Large stars which produce a few, large, bushy spark trails

Those are just some of the different effects which arise from simply varying the type of composition that stars are made from, or the star size, and/or the process used to manufacture the stars. Skylighter.com - 11 -

Chapter 1 – Stars & Shell Inserts

Star Manufacturing Processes When it comes to the different processes employed to make stars, and which can contribute to the variety of the resulting effects, there are three basic methods: 

Cutting stars



Pumping stars



Rolling stars

These three methods produce stars with shapes unique to each method: 

Square stars (usually cubic,) made by cutting star composition



Cylindrical stars made by pumping star composition (although one master pyrotechnist, who is also a master machinist, produces rectangular pumped stars with his special, hand-crafted, rectangular star pump.) Additionally, some folks have experimented with troweling damp, water/dextrin bound star composition into square-divided suspended-ceiling light grids and allowing the cubic stars to dry before ejecting them.



Round stars (spherical) made by rolling star composition in layers, as jawbreaker candy is made

Cut Stars Cut stars are quick and easy to make, and have traditionally been the stars of choice in Italian-American style cylinder shells. No special machines or equipment are necessary to make cut stars. This makes star-cutting relatively inexpensive. Cut stars can be stacked carefully in ball shells, too:

Cut-Stars Stacked in Ball Shell Hemispheres Skylighter.com - 12 -

Chapter 1 – Stars & Shell Inserts Cut stars have sharp corners and edges which make for good star ignition. They “lock together” when filled into cylindrical shell casings, enhancing the integrity and strength of the resulting shell. Since cut star composition has to be pretty wet to make it suitable for cutting, when the comp is bound with water-dextrin, the resulting stars can take longer to dry than stars made with other methods. Cut stars also have the disadvantage of not having completely consistent sizes, due to the manufacturing method. So, some of them will burn out before others after the shell bursts. They also do not have a very aerodynamic shape, compared to a round/spherical star; so they do not produce as symmetrical a pattern in the sky as round stars do. Cut stars produce only one single color or effect. Cut stars do have the advantage of being able to be made in any size batch, from a small 2-ounce batch, up through a 30-pound one. And they can be made and primed all in one single step, rather than requiring multiple layers to be built up, often necessary when rolling stars. Traditional, cube-shaped, water-dextrin bound cut stars can be made in a couple of ways. For small batches of cut stars, a “pancake” can be made out of the dampened star composition. This flat pancake is then dusted with star prime, and sliced with a thin, straight-edged knife.

“Pancake” Made into Cut Stars Skylighter.com - 13 -

Chapter 1 – Stars & Shell Inserts For larger batches of cut stars, a “loaf-box” can be made and lined with waxed paper. Damp star composition is rammed into the box to form a loaf of star comp, and the loaf is ejected from the box-frame. Slices of the loaf are then sliced off of it, and these slices are then cut into stars in the same way the pancake above was.

“Loaf-Box” for Making Large Batches of Cut Stars One more cut-star method has recently become popular for making relatively small batches of parlon-acetone bound stars–“screen-slicing.” In this method, a parlon-containing star composition is dampened with acetone, which softens the parlon (a synthetic rubber). A pancake of the damp star composition is made, and the patty is pushed through the square holes of a framed stainless-steel screen. When the patty is pushed through the screen, stars are sliced quickly, and they end up consistently sized, too. Star priming can be incorporated into this onestep slicing method. These parlon-acetone bound stars make wonderful colors and effects. Best of all, they dry very quickly, so you can use them in fireworks devices after only a few hours.

Screen-Slicing Parlon-Bound Stars and Spreading on Drying Screen Skylighter.com - 14 -

Chapter 1 – Stars & Shell Inserts

Pumped Stars Pumped stars are made by packing slightly dampened star composition into a hollow cylinder, either a single-star pump, or a gang pump called a star plate. The star composition is then consolidated with either hand pressure, hand ramming with a mallet, or with the use of a hydraulic or pneumatic press:

Single Star-Pump, Star-Plate, and Pumped Stars Typically only slightly dampened, water-dextrin bound composition is made into stars with a star pump. So, pumped stars dry much more quickly than comparable water-dextrin bound cut stars. This is especially advantageous when larger stars and comets are being made. Pumped stars stack very nicely inside cylindrical shell casings, resulting in strong shell integrity. This is advantageous when large, multi-break cylinder shells are being made. The use of single star pumps or star plates makes this method of star manufacture a little more expensive than star cutting. Looking at the photo above brings up a question: What is the difference between a comet and a star? Many fireworkers would describe the large diameter pump above as a comet pump, and the plate as a star plate. The large “puck” could be described as a comet, whereas the smaller pellets could be described as stars. Technically, any fireworks projectile fired individually out of a mortar would be defined as a comet, no matter what size. And any projectiles, fired in multiples out of shells or mines, would be referred to as stars, once again regardless of their size. Skylighter.com - 15 -

Chapter 1 – Stars & Shell Inserts So, it is the use that pumped projectiles are put to–not their size–which technically determines whether they are comets or stars. But, in practice large projectiles, as singles or groups fired from a shell or mine, are often referred to as comets. And small projectiles, even if they are fired one at a time, as is done from roman candles, are often called stars. The bottom line is that it’s not always cut-and-dried as to whether a projectile is called a star or a comet. And the distinction is not really important. Although the pumped stars shown above are pellets made with simple tooling and a single-effect composition, more complex stars and comets can also be made. Small contrasting-effect stars, such as color stars, can be mixed in with the larger comet composition, such as a charcoal-streamer or glitter formula, prior to pressing the comet. When the comet burns, the color stars stream behind it, mixed in and contrasting with the charcoal or glitter tail trailing behind the projectile. This is called a matrix star or comet. Pumped stars of different compositions may be glued together to form “married” stars. Often their perimeter is then reinforced with some tape or pasted paper. In this way, a projectile with two different effects can be created, say a blue-headed comet with a gold-glitter tail. This combined effect could not be produced with only one composition. A color-changing pumped star can be made by using a “cavity pump” to pump a star with a depression in one end of it. Once the star is dry, the cavity is filled with a star composition of a different color or effect. That end is then pasted over with paper or tape. The star begins burning from the solid end, exhibiting one effect, which then changes to a different color when the flame front reaches the inner composition.

Cavity-Star Pumps

Skylighter.com - 16 -

Chapter 1 – Stars & Shell Inserts Crossettes (splitting stars and comets) are made using only one star composition such as a charcoal-streamer or glitter composition. What makes crossettes unique is that the stars begin flying through the air as a standard star would. But then the individual stars split into fragments which fly off in opposite directions. These stars are made using a crossette pump. These pumps can either resemble the cavity-star pumps shown above, except with smaller diameter cavity-forming projections on their pistons, or they can have “cross-shaped” projections as shown below.

Crossette Pump with Cross-Shaped Cavity-Forming Tip After a crossette has been pumped and dried, the cavity in it is filled with either a loose powdered explosive, or with a small “firecracker hole shot.” Then the star is pasted with paper except for the solid end. The comet burns from that solid end until the explosive is reached. At that point the projectile splits into fragments, which fly away from each other. This sudden splitting of all the stars in a shell burst is very surprising and impressive, especially if the stars have been carefully crafted so that they all split simultaneously. So, you can see that different star pumps, compositions, and construction techniques can create different effects in the sky as the pumped stars and comets fly through the air.

Skylighter.com - 17 -

Chapter 1 – Stars & Shell Inserts

Rolled Stars Spherical stars, often called round stars, are made using a star-roller. These stars have an aerodynamic shape and fly through the air in straight trajectories. The stars can be sized during the rolling process in order to create batches of stars which have very uniform, consistent sizes. Consistent sizing of rolled stars is highly valued because it results in stars which either change color and/or burn out all at the same time. One of the really significant advantages of rolled stars is that they can be made with one color composition rolled first, followed by a different color rolled on top of that first one. This produces color changing stars. Different colors or effects are often rolled up in thin layers and allowed to dry between those layers. So the overall star rolling process can be a lengthy one. But, large batches of stars can be made using the rolling method. Advanced fireworkers can produce stars which change colors multiple times, or start with a color, go dark for a short time, and then flash on with color again, seemingly out of nowhere. Precisely rolled stars are the hallmark of the highly artistic Japanese ball shells. Star rolling begins with cores such as a small cut stars, lead shot, small seeds, or even little pieces of pasta. An advanced technique for starting star-rolling involves “spritzing” dry, powdered star composition with a water-filled spray bottle, to create cores on which to continue rolling the stars. Star composition is layered onto these cores using a star roller. The simplest star roller can be a round or flat-bottomed plastic or metal bowl. The bowl is swirled round and round by hand as the star cores are dampened with sprayed-on water, and more dry star composition is slowly added to “grow” the stars as they roll. Usually, though, a mechanized star roller of some sort is used. A round container of some sort is rotated by a motor as stars are rolled. Plastic or metal drums, large or small bowls, or even rubber tires, are used in various versions of the star roller. Using a star rolling machine usually makes this method of star manufacture more expensive than cutting or pumping stars.

Skylighter.com - 18 -

Chapter 1 – Stars & Shell Inserts

Different Types of Star Rollers, Commercial and Homemade So, in summary, simple fireworks stars can be made from basic compositions bound in pellets with binders. Many different effects can be achieved by varying the star formulas or the process by which the stars are made. But, there is a whole different class of garnitures, normally referred to as inserts instead of stars.

Garnitures Wrapped in Paper There is a category of garnitures which consists of pyrotechnic compositions wrapped in paper: pressed in paper tubes, layered between sheets of paper, or contained inside paper casings as small shell inserts.

Skylighter.com - 19 -

Chapter 1 – Stars & Shell Inserts Small insert shells can be used inside larger shells, to create a “shell-of-shells.” These inserts can be filled with any of the various garnitures we are discussing, or they can be filled with a report composition to create simple flashes of light and sound when they burst. Graceful falling leaves stars are made by troweling, like frosting a cake, soft composition between layers of paper. Once the composition is dry, the sheets of paper-bound composition are cut to size, and one end of the falling-leaves is primed to ensure good ignition. These stars softly break out of a bursting shell, and gracefully drift toward the ground dropping like colored falling leaves. Box stars, sometimes called pillbox stars, are made by pressing some dampened star composition into thin-walled paper tubes. The tubes are made by rolling about 4 turns of kraft paper on a ½-inch diameter rod, and securing the edge of the tube with glue. The star tubes are cut ¾-inch long, and a piece of blackmatch is inserted into the tube with the match sticking out of both ends of the tube. These tubes are then filled with dampened star compositions which are especially suited to these stars. Because of the embedded blackmatch, which takes and holds fire very well, these stars ignite easily and are not blown blind by a hard shell burst. The compositions used to make them burn a long time, and very brilliantly, resulting in a long duration, dramatic display of drooping brilliantcolor stars.

Box Star Insert Construction Hummers sound like their name implies; these tube inserts create a whirring sound which can be accompanied by a spiraling spray of sparks. A fuel composition is rammed between two clay plugs in a strong-walled cardboard tube. Tangentially-drilled vent holes cause the inserts to spin and whir as the fuel burns.

Skylighter.com - 20 -

Chapter 1 – Stars & Shell Inserts

Hummer Insert Construction Farfalle inserts (plural for the Italian farfalla), called butterflies in English, are constructed identically to hummers, except the two holes are drilled at the same time, on opposite sides of the tube, straight through the center of the tube. This results in a butterfly-shaped spark spray which causes the inserts to wobble and spin erratically as they fly through the air. Whirlwinds, also called tourbillion inserts, are made in a fashion almost identical to hummers, except the vent holes are drilled in the tube in a way that makes the insert spin end-over-end as it flies through the air, creating a “cyclone” of sparks.

Whirlwind (Tourbillion) Insert Construction Serpents are another variation on the theme of clay plugs and fuel rammed in cardboard tubes. Instead of vent holes in the tube, though, a serpent has one vent hole through one of the clay plugs, as would a small rocket motor. An ignition fuse is installed in that hole to ignite the fuel when the insert is ejected from a fireworks device. The resulting spray of gasses and sparks causes the serpent to fly in a serpentine manner through the sky. Skylighter.com - 21 -

Chapter 1 – Stars & Shell Inserts Whistles can be used as pyrotechnic inserts. The shrill whistling sound which results from the whistle fuel can be augmented by bright sparks if metal particles are included in the fuel. Whistle fuel is never hand-rammed, only pressed with an arbor press or hydraulic press.

Whistle Insert Construction Another creative effect can be achieved with scatter stars. These inserts burst out of the shell “blind,” with no immediate visible effect at all. Then, suddenly, out of nowhere, dozens of stars appear, shooting every which way in the sky.

Scatter Stars Insert Construction Go getters create a similar effect when they fly out of a shell burst, except their vibrant colors are visible right away. Then, suddenly, the self-propelled go getters zip in every possible direction. Skylighter.com - 22 -

Chapter 1 – Stars & Shell Inserts The method for making go getters is unique in that a liquid form of star composition is squirted out of a plastic squirt bottle into small paper tubes. A small piece of doubled blackmatch is inserted into each go getter, and the inserts are allowed to dry. The bottom end, which is not designed to ignite, is dipped in Elmer’s glue to seal it.

Conclusion You can see that this broad classification, garnitures, includes quite a variety of effects, uses, and manufacturing methods. From the simplest compositions and techniques, such as charcoal-tailed cut stars, to the most complex applications and techniques, garnitures serve a wide variety of purposes in fireworks. Simply experimenting with and learning about these ways to “furnish our fireworks devices with beautifying details” can keep us challenged for many years in the art that is pyrotechnics. --Ned Gorski

Free Fireworks Making Plans Fireworks Making 101 is the beginning of 75-part fireworks-making course that you can get online from Skylighter. Just click here to sign up for detailed plans on making all kinds of fireworks stars. The plans and projects are free. There’s no catch, no credit card required. When you sign up, you’ll receive an exciting new fireworks-making project every 3-5 days by email. Each one gives you a detailed, step-by-step tutorial that shows you exactly how to make each type of firework. Tutorials are all instantly downloadable and contain color photos, detailed diagrams, and even videos to show you exactly what to do. There is no charge for the tutorials, and you can unsubscribe to them anytime you want. You are not obligated to buy anything, although we do hope you will consider Skylighter when you need fireworks chemicals, fuse, tubes, tools, and other supplies. Start learning to make fireworks right now, by clicking here.

Skylighter.com - 23 -

Chapter 1 – Stars & Shell Inserts

Skylighter.com - 24 -

Chapter 2 – Aerial Shells

2 Aerial Shells

Skylighter.com - 25 -

Chapter 2 – Aerial Shells

No, not these shells...

These Shells! Photos courtesy of Ned Gorski

Skylighter.com - 26 -

Chapter 2 – Aerial Shells

Ways of Launching Shells Whether they are propelled out of mortars high into the sky, or launched on tops of rockets to display at the end of their flights, aerial fireworks shells are designed to fire a pattern of garnitures high in the sky.

Double-Petal Starburst from an Aerial Fireworks Shell click image to play video

Shells Launched on Rockets When a shell is attached to a rocket motor to be fired skyward, the shell is referred to as the rocket’s “heading.” Rocket headings are ignited differently than mortar-fired shells: a rocket heading will typically have a fast-burning “passfire” fuse installed in it, instead of the slow-burning time-fuse in a mortar-launched aerial shell. The passfire fuse gets ignited by the top of the rocket motor when the motor’s fuel burns through.

Plastic Can Shell Heading Mounted on a Rocket Motor

Skylighter.com - 27 -

Chapter 2 – Aerial Shells

Shells Fired from Mortars Two important distinctions before we go any further: 

The “shell” is the device which is launched into the air.



The “mortar” is the tube from which the shell is fired.

Reloadable Aerial Fireworks Shell and Mortar “Reloadable” means that once the shell is fired, another shell can be loaded and fired from the same mortar. The long ignition fuse leads to black-powder lift charge which is attached to the shell in a lift bag. The shell is loaded in the mortar, which is safely secured, and the fuse is ignited at the top of the mortar. Some consumer fireworks shells are not reloadable. They come as “single-shot” devices, with an ignition fuse installed in the side of the mortar at its base. The black powder lift charge has been dumped loose in the bottom of the mortar, and the shell has been dropped into the mortar on top of the lift powder. Those components are held in place at the bottom of the mortar by pieces of cardboard pressed down on top of the shell. With these single-shot units, the mortar is secured, the fuse ignited, and one shell is fired from the mortar, which is then thrown away.

Skylighter.com - 28 -

Chapter 2 – Aerial Shells

Parts of a Shell

Basic Parts of an Aerial Fireworks Shell Here’s the sequence of events that happens when a mortar-fired shell does its thing: 

Light Visco ignition fuse.



The Visco fuse ignites the quickmatch (“shell leader”).



The quickmatch ignites the black powder lift charge.



The lift charge fires the shell into the air from its mortar and



The flame from lift powder ignites the shell’s time fuse.



The time fuse burns through to the inside of the shell.



Inside the shell, the time fuse ignites the shell’s burst powder.



The burst powder lights the stars/garnitures,



And the shell bursts,



Throwing the garnitures out far and wide.

Skylighter.com - 29 -

Chapter 2 – Aerial Shells

Size Does Matter The most common designation of a shell is its size. At the beginning of this article large shell I am holding in the picture on the left is a 12-inch shell. The two shells used as rocket headings in the photo above on the right are 8-inchers, and the small reloadable consumer-size shell (beside the yellow mortar) is a 1-3/4-inch shell. The designated size of a shell is usually determined by the internal diameter of the mortar from which it is designed to be fired (the actual diameter of the shell itself is usually smaller than that). Some consumer fireworks shells come with mortars as small as 1-inch. Other record-setting shells have been fired from 36-inch, and even 48-inch mortars.

Paper or Plastic? Almost all shells are made from one of two types of material: paper or plastic. Most budding pyros start out making aerial shells with plastic casings, and the majority eventually switch to using paper for their shells. Standard size, plastic shell casings have the advantage of being quick, easy, and simple to assemble. But, typically, they do not produce ideal burst symmetry, and they spread plastic debris around the shoot site. Paper casings are more traditional, produce better shell bursts, and leave only biodegradable paper debris behind. But, the techniques for making paper shells are more involved, take more time, and require more practice to master.

Paper and Plastic Shell Casings

Skylighter.com - 30 -

Chapter 2 – Aerial Shells

Balls or Cans? Shells can be further classified by shape--spherical or cylindrical. The former are referred to as ball shells, and the latter as cylinder shells. The casings shown above are used to produce ball shells, like the ones shown at the beginning of this article. Ball shells have their roots in the Orient, starting in Japan, then migrating to China and elsewhere. Machine-made paper and plastic casings are used to make simple cylinder (also called “can” or “canister”) shells.

Plastic Cylinder Shell Casings More traditional, hand-production techniques are used to produce the largest and most complex of cylinder shells. These techniques originated in Italy and have flourished in Malta, and incorporate paper, paste, and string.

Large Cylinder Shells from the Past and Present

Skylighter.com - 31 -

Chapter 2 – Aerial Shells

Welcome to Aerial Shells. Will that Be a Single, Double, or Triple? Aerial shells, whether rocket or mortar fired, can have one or more “breaks.” A break is one individually-functioning shell. After firing, a multi-break shell will typically display each shell-break either separately in sequence or all at one time. Here are examples of simple multi-break consumer fireworks ball shells, combined together in one assembly, called “peanut” shells. In a peanut shell, the time fuses in all the assembled shells (breaks) typically take fire at once, from the lift charge’s flame.

Consumer Fireworks “Peanut” Shells In a “multi-break” cylinder shell, two or more cylinder shells are combined into one assembly. The fuse for the first break takes fire from the quickmatch leader, and each succeeding break taking its fire from the explosion of the previous break.

Skylighter.com - 32 -

Chapter 2 – Aerial Shells

Traditional Multi-Break Cylinder Shell Construction The above illustration is taken from the two-part series on cylindrical shell construction techniques by “A. Fulcanelli” in Pyrotechnicas IX and XI. This series is considered to be the “bible” in making Italian style, cylindrical multi-break shells.

Garnitures What the heck are garnitures? Garnitures are what an aerial fireworks shell is all about. They are the visual and/or audible effects being carried into the air to be displayed at the perfect moment.

An Overall Shell Description So, when describing an aerial fireworks shell, we’d want to include: 

How it’s getting into the air: rocket heading or mortar fired.



Its size, given as inches of diameter.



Material it’s made from: paper or plastic.



Its shape: ball shell or cylinder shell.



How many breaks it includes: single break, double break, etc. Skylighter.com - 33 -

Chapter 2 – Aerial Shells 

The effect it is designed to produce: star shell, shell of shells, etc.

“Well, I’m holding a 12-inch, mortar-fired aerial shell. It’s a paper ball shell, with a rising tail, designed to produce a large silver palm-tree effect, with two red coconuts.” Which would look like this.

Palm Tree Shell with Red Coconuts Now there is a whole lot more to making shells than what’s contained in this brief article. In fact, the variations in shell-making are probably infinite. But these are the basics, the nomenclature, and the fundamental alternatives. --Ned Gorski

Free Aerial Shell & Fireworks Making Plans Fireworks Making 101 is the beginning of 75-part fireworks-making course that you can get online from Skylighter.

Skylighter.com - 34 -

Chapter 2 – Aerial Shells

Just click here to sign up for detailed plans on making all kinds of aerial shells and other fireworks. The plans and projects are free. There’s no catch, no credit card required. When you sign up, you’ll receive an exciting new fireworks-making project every 3-5 days by email. Each one gives you a detailed, step-by-step tutorial that shows you exactly how to make each type of firework. Tutorials are all instantly downloadable and contain color photos, detailed diagrams, and even videos to show you exactly what to do. There is no charge for the tutorials, and you can unsubscribe to them anytime you want. You are not obligated to buy anything, although we do hope you will consider Skylighter when you need fireworks chemicals, fuse, tubes, tools, and other supplies. Start learning to make your own fireworks shells right now, by clicking here.

Skylighter.com - 35 -

Chapter 3 – Fireworks Rockets

3 Fireworks Rockets

Skylighter.com - 36 -

Chapter 3 – Fireworks Rockets

This is Your Audience

This is a Big Honkin’ Fireworks Rocket

This is Your Audience on Big Honkin’ Fireworks Rockets!

There are Rockets and Then There are Rockets Obviously, in this introduction to rockets, we won’t be discussing military rockets, which have a long and rich history. Neither will we be discussing rockets designed for space exploration, which we’ll leave to NASA. But leaving those aside, there is a wide variety of rocketry that folks can and do explore for purely recreational purposes. Such rockets include model rockets, Skylighter.com - 37 -

Chapter 3 – Fireworks Rockets amateur rockets, high-powered rockets, and fireworks rockets. The purpose of this article is to discuss fireworks rockets. However, in order to distinguish fireworks rockets from the other types, we will briefly mention and define each of these. The following rocketry classifications and descriptions come from Wikipedia: Model rocketry: “A model rocket is a small rocket capable of being launched by anybody, to generally low altitudes (usually to around 100-500 m (300-1500 ft) for a 30 g (1 oz.) model) and recovered by a variety of means.” Estes® rockets are an example of the types of rockets launched in model rocketry. Typically, only commercially manufactured rocket motors are used in model rocketry.

Model Rocket “Amateur rocketry, sometimes known as amateur experimental rocketry or experimental rocketry is a hobby in which participants experiment with fuels and make their own rocket motors, launching a wide variety of types and sizes of rockets. Amateur rocketeers have Skylighter.com - 38 -

Chapter 3 – Fireworks Rockets been responsible for significant research into hybrid rocket motors, and have built and flown a variety of solid, liquid, and hybrid propellant motors.”

Launch of an Amateur Rocket “High-power rocketry is a hobby similar to model rocketry, with the major difference being that higher impulse range (i.e., more powerful) motors are used. The National Fire Protection Association (NFPA) definition of a high-power rocket is one which has a total weight of more than 1500 grams and contains a motor or motors containing more than 62.5 grams of propellant or more than 160 Newtonseconds.” Commercially manufactured motors are most frequently used in high-power rocketry.

Skylighter.com - 39 -

Chapter 3 – Fireworks Rockets

A High-Power Rocket Being Readied for Launch

Fireworks Rockets in Depth In his 1947 book Pyrotechnics, George Weingart uses the term “Sky Rockets” to refer to fireworks rockets. From Wikipedia: “A skyrocket is a type of firework that uses a solid (fuel) rocket motor to rise quickly into the sky. At the apex of its ascent, it is usual for a variety of effects (stars, bangs, crackles, etc.) to be emitted. Skyrockets use various stabilization techniques to ensure the flight follows a predictable course, often a long stick attached to the side of the motor, but also including spin-stabilization or fins.” Some fireworks rockets, which employ high-powered fuels such as whistle, strobe, or hybrid fuels, blur the distinction between fireworks rocketry and other types of recreational rocketry. In general, though, the presence of pyrotechnic effects intended for entertainment is the distinguishing characteristic of fireworks rockets.

Skylighter.com - 40 -

Chapter 3 – Fireworks Rockets

Launch of a Large Fireworks Rocket by Dan Thames, 2-Inch Whistle Motor, 10-Inch Ball Shell Heading Photo by Mark Stallings Except for the project on homemade Estes®-type rocket motors mentioned above, the focus of this article and at Skylighter is on fireworks rockets. The purpose of fireworks rockets is entertainment. The rocket motor is often designed to provide an entertaining visual and/or audible effect, such as a long glittering or spark tail, or a loud ascending whistle. Additionally, the rocket motor is often fitted with a “heading,” which creates a traditional fireworks display—for example, a loud report, a shell burst of stars, or Skylighter.com - 41 -

Chapter 3 – Fireworks Rockets a display of other types of fireworks inserts—at the end of the rocket’s powered flight.

Anatomy of a Fireworks Rocket

Cross Section of a Typical Fireworks Rocket The diagram above shows the elements of a typical fireworks rocket. The top of the rocket is on the right, and the bottom of the rocket is on the left. This rocket has three main components. The rocket motor consists of the paper tube (case), which has a clay nozzle built into the bottom of it to direct the rocket exhaust. It is packed with fuel to provide thrust (“thrust fuel”) and a delay (“delay fuel”) after the thrust fuel is exhausted. The top of the tube is partially closed by a clay bulkhead which has a “passfire” hole built into it. The second component is the rocket stick, which is attached to the side of the rocket motor and extends to the left. The rocket stick provides stabilization to the rocket at lift-off and in flight. Finally, attached to the top of the rocket motor is the heading containing stars and burst. The heading is responsible for the fireworks display seen in the sky as the rocket reaches the top of its climb. The functions of the 3 components are explained in detail below.

Skylighter.com - 42 -

Chapter 3 – Fireworks Rockets

Size Does Matter Fireworks rockets range in size from the smallest of bottle rockets up through the monster rocket shown in the photo above. Although it might not seem so at first glance, there is a very big difference between, say, a 3/8-inch ID “magnum” bottle rocket and a ½-inch ID rocket motor. Calculating the cross-sectional areas of the two sizes of motor-tubes, and also the total volumes of the tubes, the fact is that a ½-inch motor is between 2 and 2.5 times as large (in terms of volume) as a 3/8-inch ID motor. This is easy to see in the next photo.

Homemade Fireworks Rockets The large skyrockets you can buy at your local fireworks store typically have ½inch ID motors. A ½-inch black-powder motor can carry a heading of between 1 and 2 ounces into the air. That’s the same weight as a spherical or cylindrical, consumer-sized, aerial fireworks shell. The handmade rockets shown above are very nice, real rockets. Yet they are small enough to be suitable for flight in almost any area where rockets from the fireworks store could safely be displayed. Moving up to ¾-inch ID motors from the ½-inch ID ones yields another 2 to 3 times increase in motor volume. So, inside diameter alone is not a good indicator of how much larger one rocket motor is than another. Half-inch, black-powder rockets are a great place to start, and I personally enjoy the heck out of making them to this day. They are small enough that they can be made quickly and don’t use huge amounts of materials. But they are large enough to really be impressive. They provide that black-powder-rocket “whoosh” as they launch, and they’re able to carry a nice payload of stars or other garnitures into the air.

Skylighter.com - 43 -

Chapter 3 – Fireworks Rockets These rockets allow plenty of opportunity to gain experience while enjoying experimentation, research and development, and plain old fireworking fun. You can lift headings the size of consumer fireworks reloadable/artillery shells far into the air with these nice rocket motors. Since they do not require the use of loud black powder lift charges, they are much quieter than mortar-fired shells. And, as opposed to a simple mortar-launched aerial shell, the rocket heading is preceded by the nice rocket-motor “tail” display on the way skyward.

Traditional Fireworks Rocket Size Nomenclature Half-inch ID rocket motors are traditionally called 4-ounce motors. Quarterpounder rockets? What does that mean? Well, the answer is, not much. It’s a relatively long and complicated story which Barry Bush relates in detail in the fireworks chapter of Pyrotechnics by Alexander Hardt. Over the past several hundred years, an evolution occurred in the nomenclature used to describe rockets. That resulted in ½-inch ID rockets being referred to as “4-ounce” rockets in the US. Similar terminology is used to describe other sizes of rockets (see table below). These designations have nothing to do with the actual weight of the rocket motors, nor their payload carrying capacity, nor their thrust. They are simply arbitrary, meaningless designations which can be difficult to remember at times, and which really only pertain to black-powder rockets. As a result, many rocketeers simply refer to their rockets by the motor’s ID nowadays. But old habits and traditions are not quick to die, so here is a table of the traditional black-powder rocket designations used in the US, and the corresponding motor ID’s and common tube-lengths (may vary slightly from one maker to another):

Skylighter.com - 44 -

Chapter 3 – Fireworks Rockets

Rocket Motor Sizes and Designations Motor ID

Designation

Tube Length

¼-inch ID

1 ounce

2.75 inches

3/8-inch ID

2 ounce

3.5 inches

½-inch ID

4 ounce

5 inches

5/8-inch ID

8 ounce

6.25 inches

¾-inch ID

1 pound

7.5 inches

7/8-inch ID

2 pound

9 inches or longer

1-inch ID

3 pound

10 inches

1.25-inch ID

4 pound

12.5 inches

1.5-inch ID

6 pound

15 inches

You can see from the table that the length of the tube is approximately 10 times the tube’s ID. This can vary a little from one maker to another, though. On the small end, there are ¼-inch ID and 3/8-inch ID “bottle rocket” tubes and tooling available as well, and we could call these “1-ounce” and “2-ounce” motors.

3/8-Inch-ID Turbo-Pyro “Magnum Bottle Rocket” On the large end, some rocketeers, with the necessary space to fly them, make larger fireworks rockets too, sometimes referring to them as “30-pound” or “60pound” motors.

Skylighter.com - 45 -

Chapter 3 – Fireworks Rockets

30 and 60-Pound Fireworks Rockets

Types of Fuel Used in Fireworks Rockets The traditional fuel for fireworks rockets is black powder, and it is still used extensively. Black powder produces that characteristic “whooshing” sound, and long tail of charcoal sparks that most fireworks enthusiasts associate with fireworks rockets.

Launch of a ¾-Inch Black-Powder Rocket click image to play video But perhaps the biggest advancement in fireworks rocketry in the past 50 years has been the development of different fuels, other than the traditional blackpowder fuel. “Whistle fuel” is used in whistling rockets, and also in conjunction with other types of fuel as a powerful booster. Skylighter.com - 46 -

Chapter 3 – Fireworks Rockets

Launch of a ¾-Inch Whistle Rocket, with Report click image to play video “Strobe” fuel, used with a whistle-fuel booster, produces one of the most striking visual, and especially audible, effects of any fireworks rocket. A brightly flashing tail is accompanied by loud “popping.” It almost sounds like an incoming helicopter.

¾-Inch Strobe Rocket Taking Off click image to play video Rockets with brilliantly colored tails can be made by using color-producing fuels. Such rockets often use whistle fuel as a booster. Powerful “hybrid fuels” can be made by mixing granulated black-powder fuel with granulated whistle fuel, and pressing that fuel mixture in motor tubes. Other fuels such as zinc-sulfur fuel, and “sugar” or “candy” fuel—to mention only a couple—have also been developed. So you can see that starting with just the rocket motor, there is plenty of room for creativity and experimentation with fireworks rockets.

Skylighter.com - 47 -

Chapter 3 – Fireworks Rockets

Overview of Fireworks Rocket Construction Methods Rocket tooling, made up of a spindle and rammers (or “drifts”), is used to form the rocket nozzle and form the hollow-cored fuel charge inside the rocket tube.

Two Different Sets of ½-Inch Black-Powder Rocket Motor Tooling

Cross-Section of a Cored Black-Powder Motor In a traditionally made black-powder rocket motor the hard clay nozzle is formed by ramming powdered clay into the bottom of the tube. This is done using the tooling, a mallet and a sturdy ramming post for a base. The spindle forms the central hole in the nozzle. The fuel in a fireworks rocket must also be compacted into a solid mass (called a “grain”) in order to ensure that burning of the fuel proceeds in a controlled fashion. This process is called “consolidation.” In the case of our black-powder Skylighter.com - 48 -

Chapter 3 – Fireworks Rockets rocket, fuel consolidation is also achieved using the tooling, mallet and ramming post. The fuel, made of potassium nitrate, charcoal, and sulfur, is rammed into the paper tube above the nozzle in a series of small “increments” to ensure consistency. A clay bulkhead with a passfire hole is rammed on top of the finished fuel grain, and finally, a heading is added at the top end of the rocket. The motor in the diagram above would be classified as a “black-powder fueled, nozzled, core-burner” motor. An “end-burner” motor would be made in a very similar fashion, but with a very short spindle which only penetrates through the rammed nozzle. The fuel grain of an end-burner black-powder motor has no core going up into the center of its fuel grain.

A Short Spindle for End-burner Motors (with fuse inserted in it)

Nozzled versus Nozzleless Motors Whereas the above mentioned motors have clay nozzles, there are black-powder motors which do not use a clay nozzle. These “nozzleless black-powder” motors have a more powerful black-powder fuel consolidated around a core-forming spindle, without any clay nozzle at the bottom end. The whistle and strobe motors shown in the previous sections do not use clay nozzles either. They typically do have a core formed up into their fuel grain.

Skylighter.com - 49 -

Chapter 3 – Fireworks Rockets

Methods of Consolidating Rocket Fuel As mentioned above, traditional black-powder motor construction employs hand ramming with a mallet and a solid ramming post.

Tools for Hand-Ramming Rocket Motors But more sensitive fuels like whistle or strobe composition should not be subjected to the shock associated with ramming. Also it is sometimes desirable to achieve higher densities of compaction. In these cases, mechanical or hydraulic presses are used to press increments of the fuel into the paper tubes.

A Modified 1-Ton Arbor Press for Pressing Rocket Motors

Skylighter.com - 50 -

Chapter 3 – Fireworks Rockets

A Homemade Hydraulic Fireworks Press

Means of Stabilizing a Rocket At the time of launch and during its flight, a rocket must be stabilized to keep it headed in the desired direction, usually straight upwards. There are three different ways to stabilize a rocket: 

Stick stabilization, as shown in the photos above of rocket motors with sticks attached to them.



Fin stabilization, as shown in the photos above of the various rocket with fins on the rocket bodies.



Spin stabilization, as employed in a type of fireworks rocket called a “stinger missile.” In these rockets, prior to launch, the rocket motor is spun by exhaust gasses emitting from a tangential spin-hole in the side of the motor-tube.

Skylighter.com - 51 -

Chapter 3 – Fireworks Rockets

Spin-Up and Launch of a Spin-Stabilized Stinger Missile click image to play video

Rocket Heading Types And, finally, after the rocket motor lifts the rocket skyward and has done its job, a heading that has been installed on the motor’s top can display. This can be as simple as a report, or as complex as the 10-inch ball shell on the large rocket shown earlier in this article. A simple star, or small cluster of them, can be taped to the top of the rocket motor, and they will signify when the rocket’s powered flight is completed. A “bag shell” heading can be constructed of a few turns of kraft paper on the motor’s end, filled with black-powder burst charge and a handful of stars. Or, any complex aerial ball shell or cylinder shell imaginable can be installed on the rocket motor to create a complex aerial fireworks display at the top of the rocket’s flight.

Summary of A Rocket’s Nomenclature Combining all these variables will yield a particular rocket’s complete description, which will include: 

The size of the rocket: motor-tube ID.



The type of fuel or fuels used in the rocket motor’s construction, along with a description of the desired tail effect.



The type of fuel consolidation used when making the motor: hand rammed or pressed.



Whether the motor has a nozzle or not: nozzled or nozzleless. Skylighter.com - 52 -

Chapter 3 – Fireworks Rockets 

Whether the fuel grain has a core in it or not: cored (or core-burner) or endburner.



Method of rocket stabilization: stick, finned, or spin-stabilized (stinger).



Type of heading installed on the rocket, and its intended effects.

--Ned Gorski

Free Fireworks Rocket Making Plans Fireworks Making 101 is the beginning of 75-part fireworks-making course that you can get online from Skylighter. Just click here to sign up for detailed plans on making all kinds of fireworks rockets and other fireworks. The plans and projects are free. There’s no catch, no credit card required. When you sign up, you’ll receive an exciting new fireworks-making project every 3-5 days by email. Each one gives you a detailed, step-by-step tutorial that shows you exactly how to make each type of firework. Tutorials are all instantly downloadable and contain color photos, detailed diagrams, and even videos to show you exactly what to do. There is no charge for the tutorials, and you can unsubscribe to them anytime you want. You are not obligated to buy anything, although we do hope you will consider Skylighter when you need fireworks chemicals, fuse, tubes, tools, and other supplies. Start learning to make your own fireworks rockets and many other kinds of fireworks right now, by clicking here.

Skylighter.com - 53 -

View more...

Comments

Copyright ©2017 KUPDF Inc.
SUPPORT KUPDF