Two inch round shells are nice since they don't consume much material yet they still create an impressive effect in the sky. Here's how I make them, with a procedure slightly adapted from Dave Blesser's book Round Stars and Shells .
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| The casing is made from papier mache formed over a golf ball. I cut the paper into strips 1 ¼" wide and 4 ¼" long, then soak them in wallpaper paste. The ball is smothered in vaseline and then wrapped with paper as shown. After 3 layers are on, I roll it between my hands to smooth out the wrinkles and set the sphere aside to dry. |
| Once dry, a cut is made around the circumference and the two halves can be parted. Sometimes I need to slip a knife under the paper to pop the hemispheres free. |
Before the shell is loaded with stars a 1" piece of visco fuse is first hot glued into one of the hemis. After that, the shell can be filled in many ways, but for symetrical bursts the stars should be lined up one layer thick. This size shell will hold between 60-80 ¼" stars depending on the priming thickness. A piece of tissue paper is then pressed down to hold the stars in place.
For the burst charge about 1-1.5 grams of whistle mix along with a black powder filler will do the trick. This is placed in the tissue paper cavity and then the two halves can be carefully joined together. The easiest way to join the halves is to cover the top half with saran wrap or tissue paper so that the contents don't fall out when it is inverted.
Actually, I've never bothered to paste these shells with more paper. Instead they're reinforced with string and masking tape or sometimes with 4-5 layers of masking tape alone. This way they can be fired immediately without having to wait for glue to dry.
The last step is to attach the lift charge and leader. It takes 5 grams of black powder to lift one of these shells to a respectable altitude.
Here are pictures of some of my very first golf ball shells from summer 1997. The stars are a basic charcoal streamer mix and the ring of blue is a veline comp if I recall correctly.
