Senko hanabi

From PyroGuide

Senko hana-bi

Senko Hanabi (incense stick firework) is a thin shaft of twisted paper about 20 centimeters long with one end containing a few grains of a special composition. Their name “Senko" means incense sticks and "hana-bi" meaning fireworks; literally: flower-fire in Japanese. Senko hanabi are always included in the packets of fireworks in japan and are always done last to finish off the family fireworks which wouldn't be complete without them.

[edit] Compositions

Takeo Shimizu describes two versions of this Japanese classic.

Senko hana-bi
Potassium nitrate	60
Charcoal or soot	10-20
Sulphur	20-30

Senko hana-bi realgar based
Potassium nitrate	35
Charcoal or soot	20
Realgar	45

Source: Shimizu[1], page 70

Senko hana-bi
Potassium nitrate	60
Sulfur	24
Charcoal pine, airfloat	16

Source: http://www.vk2zay.net
Alan Yates states Shimizu as the source for this composition. It appears to be a "Tuned" composition.

[edit] Construction

A little Senko Hanabi composition makes quite a few "sparklers" so grinding a small amount in a mortar and pestle is the most practical preparation. Try using the slowest burning charcoal for this, such as barbeque charcoal. A small quantity of black powder is twisted up in some tissue paper to make a fuse (see paper fuse). Dipping the end of the twist in a potassium nitrate solution to make it a touch paper and twist the empty end up for a few inches to make a handle. The alternative is to add a binder make a slurry and coat slivers of bamboo, dry grass or other thin sticks. Shimizu suggests 90 mg per device. Using too much will either burn the droplet off the end of the sparkler or make it too large to stick.