• Category Archives Fireworks
  • Fireworks as the Subject for School Science Projects …Color

    2007011511192673499I am frequently asked about the science of fireworks by students who wish to make fireworks the subject for their school projects. It is a fascinating subject and excellent for studying chemistry. The most common question I have always been asked is, “what chemicals make the colors in fireworks.” The answer is the color of fireworks is actually produced by burning elements.

    If you have ever taken a chemistry class, you might have performed a flame test. The flame test is used to visually determine the identity of an unknown metal or metal ion based on the characteristic color the salt turns the flame of a bunsen burner. The heat of the flame excites the electrons of the metals ions, causing them to emit visible light. Every element has a signature emission spectrum that can be used to differentiate between one element and another.

    In making fireworks, we use this characteristic nature of chemicals to produce our colors. Strontium compounds produce red, sodium and iron produce yellow, magnesium and aluminum produce bright white, barium salts produce green and copper compounds produce blue.

    These color producing compounds are mixed with oxidizers, fuels, binders and color enhancers to produce the burning “Stars,” that you see in fireworks.

    The most common fuels we use are charcoal, aluminum and red gum. Oxidizers, like potassium nitrate and potassium perchlorate, provide the oxygen needed to burn the fuel and binders, like dextrin, hold the mixture together.

    These chemical mixtures are well – blended in order to make a consistent, homogeneous mix. They are then wet and either rolled into little balls or pressed into cylindrical shapes and dried. In order to insure that they ignite well, they are coated with a black powder prime and then they are ready to be packed into a firework shell, mine or many other types of effects.


  • boys will be boys.

    I had plenty of opportunities growing up to indulge my boyish interest in pyrotechnics, my grandfather built a fireworks factory. I tagged along with my dad to the factory on many a Sunday morning mostly in silence. The few words spoken – “don’t touch that,” “get away from there,” broke his meditative silence at intervals. The musky smells of chemicals, papers and dirt, combined to fill the office with the well recognized odor of my dad’s job. You could say it stunk but I smelled the incense of heaven.


  • The Spread

     

    Jane SturgillI believe that one of most prestigious jobs in our factory had to be the finisher on the cone production line. Always a woman, she was the one to spin the final label around the cone before sending it down the line to be packaged. She was so important because her speed determined when she and her coworkers would meet their quota and leave for the day. Their day started with a new bundle of 500 sheets of paper labels and ended after fourteen bundles were neatly wrapped around a truckload of cones.

    Paper

    We touch a lot of paper in fireworks making. We roll a finish wrap on gerbs and shells or we form fuse cases from paper spun on metal rods and shell cases around wooden formers. Then we glue the wraps down. Paper can be stiff and strong, silky or mushy. A life in fireworks is as much an affair with paper as it is with fire. Paper has grain, it comes in different thickness and weights, it rolls, twists and folds. If you can’t tell which way its grain runs, you’ll know as soon as you struggle to roll up a roman candle or nose a Niagara Falls stick.

    A shipment of brown Kraft paper was heralded like the arrival of a new wine vintage; a load of bad paper could affect the mood of the factory for weeks whereas a fine vintage of soft, workable paper was intoxicating and no doubt led to a most content and highly productive workforce. I’ve seen my father and other masters rub paper grocery bags between their fingers and squint their eyes as if they were connoisseurs assessing the delicate aromas of a new red.

    To prepare paper for most work in a fireworks factory, one would take a bundle of paper, stacked neatly, and spread it enough to expose an edge of each sheet, akin to fanning a deck of cards. This is so you could paint a brushstroke of paste along each edge at once. That’s it.

    Spreading

    I can’t remember the first time I ever saw someone spread paper but I was mesmerized. Of all my skills as a fireworks maker, it is one of those that fascinates people the most. In his book entitled Pyrotechnics, George Weingart describes spreading paper this way, “Take a bundle of approximately one or two dozen sheets and lay them squarely before you on the rolling board. Holding them down tightly with the left hand, rub them gently toward you with the thumb-nail of the right hand so that each one will slide about a quarter inch below and to the left of the one under it.” He was describing rolling lance tubes and I would just add that you can use a blunt object, like a stick, if you care about keeping your thumbnail. A simple, gentle rub pulls each leaf slightly, equally and miraculously away from the next.

    I believe the reason this skill so fascinated me as a boy was that it was one of the most difficult skills to teach a new person. No matter how you taught them, they would still want to place one sheet on the table, wipe on some paste, roll it up, and do it again. Maybe it seemed just too simple and therefore unnecessary. To become a cone finisher though you had to master the skill. The head cone finisher at the factory was named Jane Sturgill. No one was ever better or faster. In all my years learning the art and craft of fireworks making, sitting across a production line from her – a simple cone finisher – learning how to simply spread and wrap, taught me perhaps one of my most cherished skills. Thanks Jane.