Pyrotechnic Formulas For Making Colored Pillbox Stars

A fine article on making pillbox stars was written by Lee Partin, late of Homosassa Springs, Florida for the best club newsletter in the US, the FirstFire. She and the club have consented to its reprinting here. Thanks especially to Rich Ogden, editor of the FirstFire, for compiling this article from three separate articles originally written by Lee, and for helping with questions and clarifications.

Pill Box Stars Everywhere

Every time we turn around, we are making pillbox stars for PGI. Red ones, blue ones, green ones, gold ones, and the list goes on. I have even made them in my dreams. Rolling tubes, mixing composition, loading and compressing them.

If you have never seen the effect of a pillbox star in the sky, you have missed one of the more spectacular pyro effects. It is essentially a tube of paper with black match extending at least a half-inch from each end and running the entire length inside of the tube. This means that when you light the star it will burn from both ends and produce a larger flame envelope (visible burning area), and it will burn for several seconds. They are often loaded in rings in canister shells, break in beautiful rings and expand outwards while falling towards the earth. Absolutely beautiful! We have probably made at least a couple of thousand pillbox stars. If you wish to try this effect, I will pass along the methods that I have learned.

Tubes: The pillbox star tubes are rolled from three turns of 60 or 70 lb. Kraft paper. The paper is cut 20 inches wide and 7-1/2 inches long, with the grain running in the 7-1/2 inch direction. They are rolled around a 3/4-inch wooden dowel or steel rod (the weight of the steel rod makes it easier to roll the tubes). Paste is applied lengthwise to 2/3 of the width of the paper over the entire length. It is then rolled up, and then slipped off of the dowel. Some people paste the entire paper, including the area that touches the rod. This is also acceptable, but the rod can get tacky and needs to be cleaned. Allow the tubes to dry slowly. Do not put in the sun (or oven), as this can cause the tubes to wrinkle or curve. Depending on the burning speed of the pillbox star composition, the dry tubes are then cut into sections from 1 inch to 1-1/2 inches long.

Filling Method: After the pillbox star tubes are rolled, dried and cut to the desired length, cut pieces of black match long enough to hang out both sides of the cut tubes by at least a half inch. Moisten the pillbox star composition only SLIGHTLY. Insert the match into the tube along the inside wall, extending from each end of the tube. Bend or fold the black match over the ends of the pillbox star tube. Hold the tube with the black match in place and dip it into the bucket of dampened pillbox star composition.

Scoop the tube full of pillbox star composition and compress gently with the finger and thumb on each end of the pillbox star tube. If the pillbox star composition compresses too much, scoop more pillbox star composition into the ends of the tube to fill it. Press again on the ends with the thumb and finger. Place on the [optional] ramming tool and tap lightly. Do not consolidate too hard; this can cause the pillbox star to burn too long.

Set it aside to dry, and repeat the process. Let the pillbox stars dry a couple of weeks.

Compositions: Here's where I get confused. One source I trust says "Many regular pyrotechnic formulas will burn too long in the pillbox star tubes," which seems to imply that the pillbox star pyrotechnic formulas should be faster-burning than those used for other types of stars. But other sources (notably Hardt, 2001) claim that "pillbox star compositions...are often slower burning than compositions used for other types of firework stars," presumably because the black match will light the pillbox star along its entire length.

Well, I'm going to let someone else tackle that question. I'll just finish with the pyrotechnic formulas our Dragon Lady gave in the three articles. All parts are by weight:

Pink & Silver Pillbox Star Pyrotechnic Formula

Potassium perchlorate 68
Strontium carbonate 14
Strontium nitrate 2
Red gum 6
Aluminum, bright 4
Aluminum, flake, small 3
Aluminum, flake, med/large 3
Dextrin +2
Moisten with no more than 8 to 9% moisture: 35:65 alcohol:water.

Red Electric Pillbox Star Pyrotechnic Formula

Potassium Perchlorate 70
Strontium Carbonate 12
Red Gum 6
Aluminum - Bright 6
Aluminum - Flitter Fine 3
Charcoal 3

Moisten with water:alcohol 80:20 until the pillbox star composition is slightly damp, and composition clumps when compressed in the hand.

Red (from Lancaster)

Potassium Perchlorate 70
Strontium Carbonate 15
Red Gum 9
Charcoal 150 mesh 2
Dextrin 4

Yellow (Lancaster)

Potassium Perchlorate 70
Sodium Oxalate 14
Red Gum 6
Shellac 80 mesh 6
Dextrin 4

Rich Ogden notes, "You just want to firm the pillbox star composition in the tubes, not pound it in. The paper case is only 2 layers of very thin Kraft and won't take any pounding and the pillbox star composition should not be pressed down too hard anyway - not like a pumped star. Some people don't use the tooling at all; just squeeze it between thumb and forefinger or middle finger. Guess it depends on the pillbox star composition, how moist and sticky, etc. But you don't want it too hard. These suckers are big (relatively speaking), and take advantage of the support provided by the paper to allow the pillbox star composition to be just a little softer than a similar-sized comet or pumped firework star; that results in a bigger flame envelope than a hard-pressed pillbox star composition"

He also notes that either Elmer's (white) glue or wheat paste can be used to make the tubes.

Materials Needed
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