First, take the three dry ingredients (ammonium perchlorate (ball milled to a fine dust), copper oxide, and PVC powder) and sieve them together three times through a 40-mesh screen. Then, place them in a container on a balance and tare it. Slowly squeeze in the appropriate weight of silicone caulk. This requires some practice to be precise. Go slow and easy so as not to add too much. Mixing requires some effort. I prefer to use an old plastic container. First I mix it with a fork as thoroughly as possible. Then, I use a wooden dowel, 1.5 inches in diameter by 6 inches long, as a pestle to try to force the strobe rocket mix through a window screen section stretched over a bowl. Not all will go through, but the kneading action will thoroughly mix even the congealed portion, which can later be grated through a wire mesh screen with 1/4-inch squares. Some folks like to use a plastic bag of the Ziploc variety to manually knead the strobe rocket mix. I prefer not to be holding it! I always wear gloves and safety glasses when working with any pyrotechnic compositions. And, I sure don’t want to make a mess of anyone’s shop who is gracious enough to allow me to work in their facilities. This strobe rocket composition is so messy that I recommend you set aside a set of tools to use with this and with nothing else. The strobe rocket composition is highly flammable as soon as it is mixed, so be careful. Use an arbor or hydraulic press, it is best pressed (do NOT hammer or ram this composition!) into strobe rockets BEFORE it has a chance to set and cure. When it cures, it’s like working with small pieces of pencil eraser. Try making cut stars before the mix cures. Or, try pressing the soft composition into tubes for strobe pots and letting them cure overnight. The strobe rocket composition actually burns quite slowly. Try burning some on the ground, outside a tube to see this effect. There are many types of silicones. Different curing systems are employed. Some may not be compatible with the other chemicals used. I do not recommend any but the most cautious experimentation with any other silicones. Further, if you place a small amount of composition on a steel plate and hit it with a hammer, you will find it is also shock sensitive. The preceding article is Copyright 2002 by Skylighter, Inc. Skylighter offers a full line of products for fireworks makers and other pyrotechnicians, including books, videos, chemicals, tubes, ignition products, stage and theatrical special effects, tools, and more. You can see Skylighter’s complete catalog at: http://www.skylighter.com For a subscription to Skylighter’s FREE newsletter send a blank e-mail to: [email protected] Notes from Steve Laduke: “[W]hat I did to the original formula to reduce the chuffing when pressed into a rocket was to substitute 2 parts of the black copper oxide with 400 mesh magnesium, granular. Ignition of the rocket is much easier and the chuffing problem is almost eliminated completely. Also, the blue color suffers slightly but the advantages of adding the magnesium greatly overcomes this loss.” LCB Notes: Attempting to press this rocket ended in a messy failure immediately after the composition was mixed. Even with light pressures (<500PSI on comp) the comp oozed out of the bottom of the rocket and lifted off the spindle. I had fair success by screening the comp through a windows screen and allowing it to cure for 3-4 hours. It seemed dry, however still consolidated well under ~500 PSI on the comp. According to the manufacturer, it takes 24 hours to fully cure. I have not tried pressing with fully cured comp.