Lances
Lances are simple in construction, consisting simply of of a paper tube filled with composition. The main difficulties in its construction lie in the filling of the tube in a proper, safe manner, the choice of composition and the means of ignition of the composition. Lances may be used attached to a wooden frame to construct texts and figures. They must then be ignited simultaneously, which can be accomplished with the use of quickmatch, a type of Fuse.
Materials
Casing: As always, paper tubes are used for casings. Tubes of 5 to 8 mm inner diameter work well. The wall thickness need not be great since it has to withstand hardly any pressure. In fact, the tube should burn away with the composition so the burning surface is able to transmit its light freely in all directions. Also, since the tube will be filled using the 'binding' method, it must allow the solvent to migrate through the walls during drying. The casing should be thick enough to protect the composition from rough handling. Roll your tubes using a glue which is insoluble in water.
Composition: A slow burning composition is usually chosen. Suitable compositions may be found in the Formulas database, and a few suggestions are given below. If the main composition is hard to ignite, a priming may be required, especially if the lance is to be used in text and has to be ignited by quickmatch. Priming compostions are also listed in the composition database. A priming suitable for the suggested compositions will be given below.
Fuse: If the lance is to be used in text or pictures, quickmatch is commonly used to interconnect the lances. No other fuse will be necesary. Otherwise, The high quality chinese sold on ths web site is good..
Composition suggestions
|
Red |
Green |
Blue |
Priming |
| Ammonium perchlorate |
50 |
54 |
70 |
|
| Potassium perchlorate |
|
|
|
74 |
| Barium nitrate |
|
35 |
|
| Strontium nitrate |
30 |
|
|
| Copper(II)oxide |
|
|
15 |
| Aluminum |
|
|
|
3 |
| Charcoal |
|
|
|
6 |
| Red gum |
15 |
16 |
15 |
12 |
| The compositions in the table on the left may be used to produce some basic colors. These compositions are modified versions of compositions taken from several sources. They may not be the brightest or most saturated, but they are not particularly sensitive and are easy to work with. All four compositions can be mixed using the diapering method, and moistened using alcohol. Use only an extremely small amount of alcohol, just enough to make the composition into a crumbly powder. The priming composition is compatible with the compositions given, as well as with common black powder. The ammonium perchlorate compositions cannot be primed with black powder directly since formation of ammonium nitrate would result. The extreme hygroscopicity of this compound would make the lances very hard to ignite. |
Construction
Bottom end plug
First, one end of the casing is sealed. This may be done in several ways, but a good way to do this is to ram a wad of tissue paper into the casing . Take some tissue paper, put it in the tube, slide a dowel in, press the tube against a flat, strong surface and give the dowel a few strong blows with a hammer. The paper should form a strong plug. Use enough tissue paper to give a plug about half as thick as the inner diameter of the casing.
Filling
1) Prepare the composition of choice and slightly moisten it with an appropiate solvent. Like mentioned, add just enough solvent to obtain a crumbly powder.
2) Then, scoop a small amount of moistened powder into the casing. Use no more than will give a layer as thick as the inner diameter of the casing.
3) Using a dowel, slightly compact the powder. Press the dowel down using just your hands. Don't apply much pressure, just enough to press the crumbly powder into a solid coherent mass. The dowel used should be 1 to 2 mm smaller than the inner diameter of the casing.
4) Repeat steps 2 and 3 untill the casing is almost full. Leave about 1 cm unfilled.
5) Now, prepare the priming composition and moisten it. As before, use just enough solvent to make the composition into a crumbly powder. Using steps 2 and 3, apply a layer of about 5 mm thickness.
6) If the lance is to be used in the construction of text and pictures this step can be skipped. Take a 2 cm length visco and insert it in the casing, allowing it to rest on the layer of priming composition. Add some more priming composition, and compress it as before (step 3). Add enough priming to fill the remainder of the casing. This should hold the visco in place.
7) Set the casing aside to dry. Allow it dry thoroughly (which takes a few days, or weeks even depending on the conditions). Do not apply heat in an attemp to speed up the drying process.
Constructing 'lancework'
One of the most interesting applications of lances and probably one of the best known as well is in lancework. Lances are attached to a frame, forming a text or picture, and simultaneously ignited using quickmatch. The frame is usually contructed from wood. There are several methods to attach and interconnect the lances. My method is to glue the bottom of a lance to the frame using hot melt glue. Some black powder is then dumped into the 5 mm of casing left unfilled (step 6 was skipped), and a piece of quickmatch is secured with tape. The following pictures illustrate the principle.
