Fuente: Departamento de Estadísticas

This article describes an experiment in both the social sciences and pyrotechnics. We de- cided to hold an Independence Day party to build and shoot our own firework construc- tions assembled from Class C items.

MOTIVATION.

Ever since the prehistoric days when our an- cestors lived in caves, humanity has had a love-hate relationship with fire. We use it to cook and to kill. We use it to destroy cities in war and to celebrate festivals in times of peace.

Fireworks are very much a part of Independ- ence Day, celebrated in the United States on July Fourth. Even those who neither see nor think of fireworks throughout the rest of the year would consider the holiday to be empty without fireworks in the sky.

We have observed that most adults consider fireworks to be a thing that you go and watch at a park. If pyrotechnics are not profes- sional, they are considered to be toys, pur- chased at stands and fired by children in va- cant lots and driveways.

Few adults think of fireworks as something that they can make and enjoy (readers of AFN are pleasant exceptions). We decided to observe what would happen if a group of adults were placed in an atmosphere condu- cive to low-risk experimentation with pyro- technics.

DESIGN

The experiment took the form of a Fourth of July party. The guests were invited, but not pressured, into trying to build some interest- ing new pyrotechnic device by putting to- gether existing "safe and sane" Class C fire- works.

It should be noted that the construction of set pieces and other pyrotechnic devices from consumer fireworks is not a novel idea. It has a long history, and is a frequent topic in AFN.

Assembly from commercial fireworks was chosen to:

Reduce risk.

Enhance the probability of success. Reduce construction time.

Attempt to stay within the law.

A work area was set up, equipped with com- mon tools, mechanical components, free "safe and sane" fireworks, and special pyrotechnic components.

The provided fireworks were described, both in terms of what they were intended to do and what extra performance might be coaxed out of them. Samples of some were ignited to demonstrate their performance.

It was emphasized that the builders could use whatever materials were available, in whatever quantity they wished, in whatever configuration they thought might produce pleasing results.

In order to reduce performance anxiety, the organizer (this author) admitted that he had no practical experience in this type of con- struction; everybody had about equal chances of success.

ITEMS MADE AVAILABLE

An outdoor construction area was set up and supplied with these tools:

workbench

drill (battery-powered) drill bits (assortment)

circular saw (battery-powered, midget) hammer

hot glue gun extension cord tape measure pliers scissors screwdrivers staple gun

Safety equipment was available and verbally offered, but not piled up near the tools.

The following mechanical components were made available:

4-foot lath (10 pieces were supplied, 8 were used) cable ties clothes pins masking tape rubber bands string (cotton)

cardboard tubes (cores from rolls of toilet paper and paper towel) duct tape

spools (from sewing thread) film cans (plastic, 35mm film) 2x4 scraps

plywood scraps

corrugated, from old boxes chipboard (plain flat) nails

screws

hot glue sticks staples (for gun)

thread (heavy duty for carpets and upholstery)

The following special components were made available:

fuse (visco type)

igniter cord (Mantitor brand)

SHOOTING AREA

The shooting area was a concrete sidewalk, a traditional location for store-bought Inde- pendence Day fun.

Spinning pinwheel fireworks were accommo- dated by an A-frame ladder with a large scrap of plywood leaned against it. A piece of scrap wood attached to the plywood gave two inches of standoff. Spinners were attached to that scrap with a screw.

The following equipment was available in the shooting area:

click-start propane torch bucket of water

fire extinguisher (dry chem.) garden hose

spinner support (ladder, plywood, standoff, screw)

In honor of Independence Day, we chose to fly the flag of the Culpepper Minutemen.

SOCIAL OBSERVATIONS

Eight adults attended the party. After chips and dip, the details of the fireworks con- struction opportunity were announced. All of the males exhibited some interest in con- struction. The females were interested in watching, but showed no inclination to ac- tually build or shoot anything.

When the construction area was ready, abso- lutely nobody showed interest in building anything. This author decided to get up and put something together, and proceeded to build a spinning pinwheel device.

Completion of this device seemed to spark some enthusiasm and another male set to work building things. His products turned out all to be wheels, the smallest two feet in diameter and the largest about six feet. An- other male joined after about an hour. He specialized in enhancing commercial ground spinners, building three according to one design and one according to another. He also built a pinwheel. The author built three pin- wheels, each of a different design, in hopes that one would work well, and a line rocket.

During all of the construction, another male hovered nearby. He seemed to be interested in building something, but vocally expressed his disbelief that he could build anything that would function. Verbal reassurances were unable to overcome his reluctance.

PYROTECHNIC OBSERVATIONS

As a general rule, it appears that consumer fireworks are carefully engineered to produce the effect that they advertise, and absolutely nothing more. If an item is advertised as pro- ducing a fountain of fire, don't plan on using it for a driver for a wheel, because the design is probably optimized to produce the fire in as cheap a manner as possible, and that means no significant thrust.

Red Lantern brand "Piccolo Pete" whistles produced so little thrust as to be unusable as drivers for wheels or line rockets. TNT brand "Amazing Fountain" produced nice fire, but insufficient thrust. It is possible that these devices will drive a wheel, if it is precisely balanced a n d / o r several devices are firing at once.

TNT brand "Ground Bloom Flowers" made excellent drivers for wheels. They were also tried as motion bases for TNT brand's "Mad Dog Fire Crackle". One out of three devices built on that principle worked very well. The others appeared to have sufficient thrust, but did not spin. This configuration seems to re- quire a precise weight balance.

Model rocket engines made effective drivers, as one would expect. They must be firmly attached in order to keep them from ripping loose and flying all over the neighborhood.

The "Fire Ants" from China Pyrotechnics were tried as a motion base for a pair of TNT brand "Flashing Fountain" pieces. This didn't work, seemingly because Fire Ants are al- ready built on the edge: adding a little extra weight kept them from spinning.

Lighting an entire package of six Flower Bas- ket brand "Camellia Flowers" at once was very simple and inexpensive, but entertain- ing.

Due to recent regulatory changes, almost every "safe and sane" device offered for sale was fitted with a visco style fuse. The intent is to reduce ignition from sparks hitting the side of the fuse as well as provide a minimum time for the operator to escape. It also com- plicated the assembly process since just crossing pieces of visco and tying them to- gether will not guarantee ignition. We got good results by placing the two fuses side by side for an overlap of 1/4" and folding duct tape over the joint.

WHAT SHOULD BE CHANGED, TECHNICALLY?

Next year, we plan to add the following me- chanical components:

aluminum foil bailing wire

counterweight material

The following additional tools would prove helpful:

wire cutters

cable-tie installation tool

trash can (for non-pyrotechnic con- struction waste)

Next year, we plan to add the following spe- cial components:

black match quick match steel wool

Since so many of the experimental pyrotech- nics were spinning pinwheels, we will invest some time in devising a quick mount and dismount system for them. We also need a better way to manage the fireworks before they are shot. Perhaps a large "ready box" should be built.

TNT brand "Morning Glory" sparkler re- placements should be investigated as an in- expensive component of lancework.

TNT brand "Dinosaur Fountains" are pleas- ant. It wouldn't hurt to try a couple of them as drivers.

WHAT SHOULD BE CHANGED, SOCIALLY?

There was considerable skepticism, or down- right pessimism, that a normal person can safely and effectively do something meaning- ful with consumer fireworks. This attitude is difficult to overcome. It is also somewhat dif- ficult to understand, given that there is no way to lose: all the materials were provided for free; everybody understands that the constructions are experimental, so nobody will call you a fool if the experiment is less than successful; even when a whistle fails as a driver, it still does a great job of whistling.

Next time, we will have some experience to suggest what will and what will not work. Perhaps we should start with a brief discus- sion of known good techniques and then demonstrate a previously-built example. Add some children. Try to encourage participation by the females.

CONCLUSION

Results were inconclusive. We look forward to repeating this experiment again and again. DG