Diary of a Pyro

Copyright © 1988 - 2005 John H. DuBois III

Chapter Two

A new chapter opened in my life when I entered seventh grade. The reason is that I left the public school system at that point, and (with Laurence) began attending a boarding school in Watsonville named St. Francis. This school certainly had its flaws. For example, there were only boys there; the only women we saw were the day students' mothers when they came to pick them up and the nuns peeking out into the dining hall to see whether we were enjoying the food. However, it had an important redeeming virtue: given the size of the student body (105 total day and boarding students) it had an amazing proportion of pyros. Also, it had one pyromaniac science instructor.

My first clue to the environment there occurred when one of the Fathers told us that another student was going to give us a demonstration of rocketry. We went out into one of the large fields, where the student, Tim, had set up his equipment. It was a type of rocket I had never seen before; it actually had fins and lifted off from a launch rod (to guide it in its early moments of flight.) He pressed a button and it went up with a loud FWOOSH, disappearing into the sky. It was fantastic. Finally we saw the parachute open and it came drifting down. I soon made the acquaintance of Tim.

He told us that hobby shops not only sold rocket engines, but model rockets to put them in as well! This was something I had never realized. The next weekend when my brother and I went home, we picked up engines and rockets. In my eagerness to get my rocket flying I put it in front of the heater to speed the drying of the glue. This proved to be a mistake. When I launched the rocket, the parachute did not deploy correctly. I recovered the remains and found that the parachute had melted. At first I thought that the ejection charge had done it, so when I repaired the rocket I did exactly the same thing again but increased the amount of parachute wadding (which is supposed to protect it.) When I ended up with the same result, I finally realized what I was doing wrong. My third launch was a success; I was on my way.

Rocket launches were soon almost a daily feature at St. Francis. Others with such inclinations came out of the woodwork. I remember John, John, Francis, Tim, my brother and myself as being among the more active. I eventually made a launch kit out of an old metal Erector Set box. It had the launch material inside it, along with a battery, and a hole in the top of a launch rod. The surface of the box itself served as the launch pad. Tim showed up one day with a camera timer which he used to set off his rockets automatically without a remote button at the end of a cable, which was the usual method. I added the same functionality to my box in a somewhat more crude way with a geared motor, while retaining the option of the pushbutton trigger. Francis built a somewhat more odd handheld launcher. He stuck a handle to a large coffee can, and had a launch rod projecting out of its open end, so that he could aim it and fire. It looked dangerous so he kept it out of sight when the school officials were around.

For a while we were content to launch the standard model rockets. Soon, however, we began to implement our own designs. These often were not so stable. My attempts at building a three stage rocket quickly became infamous; they tended to turn 90 as soon as they were off the launch rod and start chasing people around the quad. Sometimes the unusual behavior was intentional. I ground the ejection charge cap off of an upper stage engine so that it could be used as a booster stage. Upper stage engines have a delay and an ejection charge so that they can deploy a parachute after coasting for a while. They have a plaster-like cap in the end to make the charge explode better and to protect the parachute (along with the parachute wadding.) Booster engines flame out as soon as they are done. If the cap is ground off of an upper stage engine it will ignite a further stage. I made a two stage rocket and used such an engine, with a seven second delay, for the first stage. The result was that by the time the second stage when off the rocket was pointing toward the ground from on high. It impacted near the pool. The remains were nicely mangled, with an accordianized body tube and shattered nose cone. It was intended as a test for a similar rocket that would have powder and an impact fuze in the nose. Perhaps fortunately, I never got around to making that model.

The school authorities generally approved of our rocketry since they realized we were learning from it. But, we eventually began to delve into other areas. One day I realized the implications of the fact that the engines we bought were filled with gunpowder. I proceeded to pound the solid core out of an engine with a hammer and grind it up. I then poured it into the casing of an expended engine, hammered a marble into the open end to seal it, and put a piece of firecracker fuse in the nozzle. My first homemade “device”! I brought it with me when I returned to school. We went down by the lake and lit it, and it exploded thunderously. Though tedious to construct (pounding and grinding the powder was a pain), and rather expensive since the powder came from rocket engines, this type of device served us well for some time. Tim eventually discovered that his father had powder around for use in his musket. He filled a little plastic film cannister with it and brought it to school. He gave some to me to try in a device and I found that it worked quite well. After that, every so often when he returned from a visit home he would bring a cannister of it with him, and sell it to me. I think I paid him 50¢ for each little can. It was cheaper and easier than grinding up rocket engines, though I still had to do that whenever I ran out of powder from Tim.

I bought fuse for my creations from one of the Johns. Though it was more benign than the powder Tim was selling me, John was more paranoid. He wound the fuse up into a tiny little coil and passed it off to me in the quad during breaks. Before he showed me blasting fuse, I had always used the long piece of paper fuse that ties a pack of firecrackers together. We ended up with pieces of it whenever we unwound packs to remove the individual 'crackers. But, that type of fuse is not very rugged or reliable. The green blasting fuse that John bought at his hobby shop was wax coated and burned at a steady rate. They sold it for use in rocket engines; it was small enough (764″, 3mm) to fit in the nozzle. It had never occurred to me to put a fuse in an engine, since even the those first rockets I had seen at the beach long before were electrically ignited.

Blasting fuse is easier to use than electrical ignition, but before we got the hang of putting the fuse in correctly it failed more often. Also, unlike an electrical igniter, if it didn't work the first time it wasn't possible to just put in another one and try again. The fuse crud had to be cleaned out of the nozzle first, and often it wasn't possible to clean it out well enough. If it failed a second time, we would usually remove the engine from the rocket, grind off the ejection cap from the top, and put a match to that end just to watch it burn. Most of us continued to use electrical ignition for rockets, saving the fuse for our other items, especially since John sold it to us for an exhorbitant price. Fortunately, Laurence eventually discovered that they sold it at our hobby shop. They kept it behind the counter and I had never thought to ask. John had never told us how much he actually paid for fuse; we discovered that he was making quite a profit. We should have suspected that he bought it cheap, since when he launched his own rockets he usually used a foot (30 cm) or so of fuse, while we would typically stick only an inch or two (3 to 5 cm) on ours. When we kidded him about it he claimed that his parents insisted that he use the long fuse to give him time to get well away; a foot would burn for about 30 seconds before igniting the engine. I considered the possibility that he was telling the truth, but I think he may have just liked to watch the fuse burn and let the suspense build.

Since we made devices from expended engine casings, they fit perfectly into rockets. I soon mounted one in a rocket in such a way that it was ignited by the rocket's ejection charge (which normally popped the 'chute.) The rocket sailed off into the blue, and the special payload worked beautifully, turning the rocket into confetti high in the sky. This gave me an idea. Since one of the Johns was particularly mellow, I decided to play a little joke on him. I slipped into his cubicle in the dorm and put one of these things into his rocket, which was sitting on his desk all loaded and ready to go. Later that day, he brought it out and launched it. While he waited for the parachute to deploy, I waited for it to explode, and indeed it did. Little bits of rocket tube came drifting down. I told him what I had done and apologized, but he thought it was rather funny.

I also played a joke on the other John. I had a decrepit rocket which wasn't really capable of another launch. Therefore, I mounted one of my repacked casings in it where the engine normally goes, put an electrical igniter in it, and brought it out to “launch”. I then asked if anyone would like to have the privilege of pressing the button. John spoke up, so I let him do it. I backed away and plugged my ears. John got quite a start when the rocket was reduced to smoke and shreds about ten feet away from him. Father Al, one of the stricter ones, came over to investigate since we weren't supposed to be playing with explosives, but I explained that it had been a defective engine…

The pyro-inclined instructor was named Bill. He once mixed up several pounds of sulfur-zinc rocket propellant in the school lab. However, he decided that it would be too much trouble to make a rocket with it, so he dumped it in a pile in the quad and, after a bit of difficulty, managed to light it. It burned quite spectacularly. I remember that afterward the ground where it had been was actually glowing. When he demonstrated burning magnesium in science class, he just pulled some off of a roll and lit it, unraveling more from the roll as he lectured. Laurence so liked this that he filched the roll from the lab. He brought it into the bathroom and lit it as we watched. He unrolled it just as Bill had, and in fact burned the entire lot. We were so mesmerized by the brilliant flame that we didn't realize that the bathroom was filling with smoke until it was done.

One week, Tim returned from home with an M80. It was the first one I had ever seen. He wanted to put it on a rocket, but couldn't figure out how to get the engine to ignite it. Instead, he just fit it into the tube at the top of the rocket, with the fuse sticking out the side. One of us would light it, then Tim would press the button. Somehow Bill became aware of our plans, but he didn't put a stop to it. He just insisted on lighting the M80 himself. We gathered out in the quad and Tim set the rocket up. Unfortunately the cable on his ignition system was only a few feet long meaning that he was rather close, but he wasn't worried. Bill lit the fuse, quickly moved away, and Tim pressed the button. Nothing happened. The fuse burned closer and closer, and still nothing happened. Bill yelled for Tim to get away, but he doggedly held the button down. At the last moment, just as would happen in a movie, the rocket launched. It didn't get a chance to climb to 1000 feet; instead it exploded when it was no more than 30 feet overhead. The engine, still burning and with remnants of tube and fin attached, shot around wildly. We thought it was great fun.

Bill also was into photography. He once took a picture of one of Tim's rockets launching. I didn't think he'd be able to since they seemed to me to depart instantly from the pad, but when the prints came back it turned out that he had succeeded. I was quite impressed. For some reason Tim didn't want to be in the picture; instead I was in the background.

A favorite passtime at this school was match wars. We would all stock up with many packs of paper matches, then go about flicking burning matches at each other, striking them as we sent them on their way. This sounds rather stupid, and undoubtedly was, but it was a way for boys locked away from the rest of the world to pass the time. The only times we were burned were when the matchheads would stick to our fingers instead of heading off toward the enemy. By the time we were done the quad would be littered with burned matches and empty match packs.

Another thing we played with were rubber-band powered airplanes. This naturally induced various experiments. I tried to boost one with a RATO unit by gluing a rocket engine on, but the wings ripped of in the first moment of flight. We sometimes taped firecrackers on, wound up the rubber band, lit them, and let them go. They disintegrated impressively in midflight.

It was at St. Francis that I saw my first tennis ball cannon. One day, one of the students brought an odd-looking contraption out to the quad. It looked like three cans taped together end to end. I watched idly as he squirted some lighter fluid into one end, swung it around a bit, put a tennis ball in the same end, set it on the ground, and put a match to its base. I was astounded to hear a loud “THOOOP!” and see the tennis ball fired high into the sky. It seemed to me that nothing so simple could possibly produce such a desirable effect. In a moment I was plying the fellow for its principles and design.

It was, indeed, constructed of nothing more than masking tape and three ordinary soda cans (though “ordinary” meant steel back then). The can tops which would block the interior of the final product had holes in them made with a punch-type can opener; the can bottoms which would block the interior were cut out with a rotary can opener. The top inch or so (the crimped-in part) of the can which was to form the “muzzle” of the cannon was cut off so that a tennis ball could be inserted. The bottom can was always attached with its base down, so that the bottom of the cannon was completely blocked. A small hole was made in the side of the cannon near its base. In operation, lighter fluid was squirted in the open end, and it was swung about to draw some fresh air in and mix it with the fuel. Then a tennis ball, which happened to fit perfectly, was inserted. The device was set on the ground and a match was put near the small hole at the bottom. The naptha fumes would ignite explosively, sending the ball an amazing distance into the air.

I was delighted by its elegant simplicity. Of course, the next time I went home I gathered together the necessary materiel and built one so I could join in the fun. The Fathers seemed to consider it a harmless pursuit and occasionally stood by watching us. Tim once brought a vial of gasoline to school, with the idea (which seemed perfectly reasonable to me) that it would be much more powerful than lighter fluid. It was with some trepidation (and considerable debate about who would apply the match) that we tried it. However, it turned out to be an inferior propellant, so I kept buying large-size cans of Ronsonol.

I eventually made dozens of cannons, varying such parameters as the size of the internal holes and the number of cans to get optimum performance. It seemed to me that the best design would surely be one which had no internal barriers at all. I assumed that the popular design was a result of the difficulty of cutting out the tops of the cans. The tops of the bottom two cans couldn't be cut off, since the ring at the top was necessary to attach them to the cans above them in a sturdy manner, and the middle of the tops couldn't be cut out with a can opener because (unlike the bottoms) they were crimped too deep. I finally managed to peel the metal out of a couple of can tops, and was disappointed to find that performance of the cannon I made with them was distinctly poorer. Perhaps the barriers helped to briefly contain the explosion and gain more thorough combustion. Four cans also didn't seem much better than the original scheme, and made it more difficult to stand the cannon up on uneven terrain, so I stuck with three. I came to the conclusion that the basic model was close to optimal already. The only change I made was to use duct tape instead of masking tape. In later years, however, I did considerably improved the design.

I spent only one year at St. Francis. After I left, I missed the community of pyros there, but eventually found local friends who enjoyed similar pursuits.


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