Flash works are a type of firework that produce a flash of light and a loud bang. They are a popular firework effect used in professional firework displays as well as in consumer fireworks. Some key facts about flash works:
– They produce a bright flash of white or colored light. This flash usually lasts for just a fraction of a second.
– They also create a loud bang sound. This is from the explosive charge detonating.
– Flash works come in many varieties and effects. Some shoot white or colored sparks or flaming bits too.
– They are made by filling a cardboard or paper tube with flash powder. This is the pyrotechnic powder that creates the flash and bang.
– Larger flash works require more restricted fireworks mortar tubes to safely launch them into the air.
– Flash powder usually contains a mix of fine aluminum or magnesium powder combined with an oxidizer like potassium perchlorate.
How Do Flash Works Create Light and Sound?
The light and sound from flash works comes from the explosive reaction of the flash powder. Here is a more in-depth look at the process:
– The cardboard tube contains the flash powder and a fuse inserted into it.
– When the fuse is lit, it burns down into the tube and ignites the flash powder.
– The flash powder then undergoes a rapid explosive reaction. This generates a lot of gas and heat very quickly.
– The hot gases expand rapidly, building up high pressure inside the tube. This pressure causes the tube to burst open.
– When the tube ruptures, the hot gases and incandescent particles inside are exposed to the open air. This creates a bright flash of light.
– The rapid expansion of gases also creates a loud shock wave. This shock wave is heard as the loud bang noise.
– Any sparks, flames, or effects are also produced at this point due to additives put in the flash powder.
– The whole reaction happens extremely fast. The tube bursts open and the flash is produced all within milliseconds.
So in summary, the chemical reaction of the flash powder produces gas, heat, and pressure which creates the visible and audible effects when it ruptures out of the tube. The size of the tube and amount of powder can be varied to create different effects.
Types of Flash Works
There are many types of flash works that can be found in professional firework displays. Some major categories include:
Salutes
Salutes are the simplest and loudest type of flash works. They contain just enough flash powder to create a loud bang. Salutes come in sizes ranging from the tiny 1-inch (25mm) bang snaps to large 3+ inch (76mm) salutes. The most common sizes though are 2-2.5 inches (50-60mm) which make a very loud aerial salute.
Report Strobes
Report strobes add a bright flash to a salute blast. They contain additional powder besides just flash powder to produce a brief burst of colored flames or white sparks. This creates a loud bang accompanied by a flash of light in the sky.
Flash and Sound Effects
These flash works produce a specific visual or audible effect along with the standard loud bang. For example, crackling flash works add crackling sparks. Whistling flash works have an additive to make a shrieking whistle noise. Colored flame flash works include extra compounds to color the burst of flame.
| Flash Work Type | Effects Produced |
|---|---|
| Crackling | Loud bang with crackling sparks |
| Whistling | Loud bang with whistling sound |
| Colored Flame | Loud bang with burst of colored flame |
| Flashing | Loud bang with bright white flash |
| Silver Salutes | Loud bang with silver sparks |
Multiple Effects
Bigger flash works shells can combine several effects in one. For example, a flash work might first shoot out a ring of colored stars, followed by a flash and whistling noise. The largest shells may have multiple bursts of lights, colors, and sounds.
Flash Powder Compositions
The main chemical powder inside flash works that produces the flash and sound is known as flash powder. There are two main types of flash powder used:
Potassium Perchlorate Flash Powder
– Uses potassium perchlorate as the oxidizer
– Typically contains 70% potassium perchlorate, 29% aluminum powder, and 1% sulfur
– Produces brighter light but less smoke than black powder flash powder
– Reacts explosively at around 2,500°F (1,370°C)
Black Powder Flash Powder
– Uses black powder as the oxidizer
– Typically contains 50% black powder, 50% aluminum or magnesium powder
– Produces more smoke but less light than potassium perchlorate powder
– Reacts explosively at around 1,800°F (980°C)
Making Flash Powder
While flash powder can be purchased pre-made, it is simple enough to make at home with the right chemicals and safety precautions. Here is an overview of home flash powder production:
Supplies Needed
– Oxidizer chemical – potassium perchlorate or black powder
– Fine metal fuel powder – atomized aluminum or magnesium
– Percentage scale for measuring out mixtures
– Mortar and pestle to mix and grind chemicals
– Powder funnel and spoons for transferring
– Paper tubes for filling
– Safety equipment – face shield, gloves, mask
Instructions
1. Use the percentage scale to measure out the flash powder ingredients in the desired ratio. Common ratios are 70% oxidizer, 30% metal fuel or 50/50.
2. Pour the measured chemicals into the mortar. Add a small amount at a time to avoid spillage.
3. Grind the chemicals together thoroughly using the pestle. Continue grinding until the mixture appears uniform.
4. Funnel the flash powder into the paper tube. Tap the tube to settle the powder down.
5. Fold over the ends of the tube and tape it shut. Store finished tubes in a cool, dry place.
6. Always wear safety goggles and gloves when handling flash powder. Work in small amounts on a non-sparking surface.
7. Follow all safety laws and regulations regarding flash powder and fireworks in your region.
With the right techniques, flash powder can be produced at home to create custom flash works. However, extreme caution is necessary given the explosive nature of these chemical powders.
How to Use Flash Works
There are couple main methods for using flash works to produce visual and audible firework effects:
Launched Fireworks
– Use a fireworks mortar tube to safely launch flash works into the air
– Load the tube with the desired effect shell and a lift charge
– Light the fuse and quickly move away
– Shell launches out and ignites high in the sky for maximum effect
Ground Level Sparking
– Place flash works on the ground and light fuse
– Quickly move away after lighting
– Flash work detonates on ground, should be on hard open surface
– Good for salutes and smaller flash items
Embedded Into Other Fireworks
– Flash powder can be embedded into firework stars, rockets, etc
– Adds flash and bang effects to other aerial fireworks
– Use by experienced pyrotechnicians only for complex fireworks
– Adds excitement but requires careful construction
No matter the launch method, always follow standard fireworks safety practices. Wear eye and hearing protection, have a water supply nearby, and launch in a clear open area away from people or structures.
Legality of Flash Works
The legality of purchasing, owning, and using flash works depends on where you live. Some key legal considerations:
United States
– Consumer fireworks laws vary by state. Some states allow all types of 1.4G consumer fireworks including flash items like firecrackers and bottle rockets. Other states prohibit anything beyond sparklers and fountains.
– Many states prohibit sale and use of professional 1.3G display fireworks like large flash works shells without a pyrotechnician license.
– Federal law prohibits the mail-order sale of any fireworks including flash items.
Canada
– Flash works and firecrackers are classified as restricted explosives under federal law.
– Consumer fireworks laws vary by province. Some provinces allow consumer fireworks with smaller flash powder charges. Others prohibit anything beyond low-hazard novelties.
– Display fireworks are prohibited without a valid fireworks supervisor certificate per federal law.
United Kingdom
– Flash works and firecrackers are generally prohibited for sale and use by the public.
– Consumer fireworks are limited to low-hazard categories like sparklers, smoke devices, fountains, and Catherine wheels.
– Professional display fireworks require an explosives license from local authorities.
Safety With Flash Works
Flash works involve explosive powder charges and can be dangerous if not handled properly. Here are some key safety tips:
– Wear eye protection – flash powder can throw heated particles at high speed
– Use ear protection – flash works make extremely loud noises that can damage hearing
– Only light one item at a time – never try to relight a dud
– Have a water supply and fire extinguisher on hand
– Launch aerial items clear of crowds, buildings, vehicles etc
– Follow instructions from the manufacturer
– Use caution lighting hand-held fireworks – have fuse facing away from people
– Dispose of duds carefully – do not attempt to relight or dismantle
– Supervise children carefully around any fireworks
– Follow all local laws regarding fireworks and flash items
With responsible use, flash works can provide exciting firework effects. But their explosive power means following safety precautions is essential.
Conclusion
In summary, flash works are a type of firework designed to produce a loud bang accompanied by a bright flash of light. They work by using a pyrotechnic flash powder charge that explodes inside a cardboard tube, rupturing it to release the flash and sound. There are many types of flash works available ranging from small firecrackers to large aerial shells. While home manufacture is possible, extreme care must be taken when making or using flash powder. Following local laws and emphasizing fireworks safety practices will help ensure using flash works is an enjoyable experience. With their exciting sights, sounds, and effects, flash works are a staple component of both professional and consumer firework displays.