The First Step in Making Aerial Shells

Fireworks shells are incredibly popular to make. About half of all new fireworks makers tell us they want to learn to make shells first.

Well, if you're going to make fireworks shells, read this article first.

There's no project here. It's just information. But it's what you need to know before you dip your toe into the incredibly rich and exciting world of shell making. This article will show you what types of shells can be made, ways they can be used, and the names of the various parts of shells.

This is important stuff. For instance, we hear from a lot of folks who tell us they want to make their own "mortars."

We've learned the hard way that what they really want are fireworks shells, not mortars (the tubes from which the shells are fired).

Look, I don't want to sound mean about this, but when you get into fireworks-making, it's important to at least sound like you know what you're doing. Believe me, a lot of experienced fireworks makers will avoid you like the plague if you don't know what you're talking about.

Think about it: do you want to be hanging around somebody making explosives, who doesn't even know the name of what he's working on?

I didn't think so.

Shell making is one of the most complex fireworks tasks you can undertake. To make shells that actually work they way you want them to, you need a variety of parts:
  • Shell casings (homemade or bought)

  • Quick match to ignite the lift charge

  • Coarse black powder (or a rocket motor) for launching the shell

  • Time fuse or spolettes

  • Stars or some other inserts in the shell

  • Fine black powder in one of several forms for bursting the shell
And, of course, you need the knowledge of how to put all these parts together in such a way that your shell actually functions correctly. This article shows gives you a quick overview of how all these parts come together.

So, before you dive into the complexities of shell making, read this article first. And then I suggest you go right to the article on making stars and garnitures--the "guts" of aerial shells. Once you've devoured those two articles, you'll be equipped to figure out where you want to go from there.

Next, you will have to either get or make all of the parts listed above. If you are subscribed to our email list, we'll show you how, and provide kits with all of the parts you'll need. So, if you're not receiving Skylighter's free fireworks making projects by email, just click the link to sign up.

Believe me, there are a lot of options. I figure that there are basically an infinite number of the kinds of shells you can make. Have fun.

Harry Gilliam

Shells, An Introduction

By Ned Gorski

Six different sea shells
No, not these shells...

Ned Gorski with his firework shells
These Shells!

2 Ways of getting shells up in the air

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. What are "garnitures?" Well, read on.

Double-Petal Starburst from an Aerial Fireworks Shell

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.

Canister shell rocket heading
Plastic Can Shell Heading Mounted on a Rocket Motor

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.
Homemade aerial shell and fiberglass mortar tube
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.

Parts of a shell

Homemade aerial shell and fiberglass mortar tube
Basic Parts of an Aerial Fireworks Shell

Here's the sequence of events that happen 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.

Size does matter

The most common designation of a shell is its size. The large shell I am holding in the picture above 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 firework shell casings
Paper and Plastic Shell Casings

Balls or logs?

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 cylindrical fireworks shell casings
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.

Plastic cylindrical fireworks shell casings
Large Cylinder Shells from the Past and Present

Welcome to fireworks. 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 firework double-break peanut shells
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.

Multi-break cylindrical firework shell diagram
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.


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.

For more on fireworks stars and other types of garnitures, see this article:

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.
  • 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.

Silver palm firework with two 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.
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