Homemade Fireworks Mine Construction
A mine is a quantity of firework stars, small comets, inserts, etc., which are simply fired up into the air from a mortar tube so that their effect is immediately noticeable as they exit the muzzle of the mine mortar. The simplest mine is a single spray of colored firework stars. More complicated mine designs can exhibit several layers of color, or color with reports, whistles, spinners or small shells. Mines are fast and easy to make, and provide a dramatic effect.
Mines are low-level fireworks and designed to work roughly in the same spatial parameters as roman candles and comets. Since their effect starts at ground level and goes up to only several hundred feet at most, they are a great way to visually tie together ground pieces, such as lancework and wheels, with aerial shells. Mines can be constructed quickly and easily, and offer the beginner lots of opportunities to experiment with various types of firework stars and inserts, without getting into the intricacies of shell building. Mines are most effective when fired in multiples, and the individual mine tubes do not have to be large for the effect to be spectacular in a show.
I like to categorize mine construction into 2 basic types, which I call "drop-in mine bags" and "pre-loaded disposable mines." Drop-in mine bags are constructed similarly to a shell with a quickmatch leader and are designed to be dropped into a mortar at the shoot site and to be fired by lighting the leader protruding from the top of the mortar. Traditionally this style is probably the most common way of using mines, at least for public displays. However, for the sake of this article, only the preloaded disposable method will be covered as it is somewhat simpler to make and can be readily used with multi-shot display boards (cakes). You can see exactly how I make these mines are made on Skylighter video #VD0060D, How To Construct Mines.
- Begin by making up several single-shot test mortars. A plastic base will work fine for 2" or smaller diameter tubes, but on larger diameters a wood base or plug is preferable. Once the correct amounts of lift and firework stars have been dialed in, you will want to make up some multi-shot mine boards too.
- Next take one of the cardboard discs and punch with the awl (6 or 8) 1/16" diameter holes in it. (If you do not have disks, you can use 2 inch end plugs, #PC2000). You can also drill these holes if you prefer. The pattern of holes can be as neat or as sloppy as you like. Set the perforated disks aside.
- Using the same awl, punch a fuse hole at the very bottom of the mine mortar so that when the visco is inserted it lies flat against the plug or base on the inside of the mine mortar tube. The fuse can be left unglued if the hole has not been made too large or the fuse can be secured in place with a dab of hot melt or white glue.
- Place a level 1/2-tablespoon of 2FA Black Powder in the mine mortar (about 8 or 9g.).
- Insert the perforated disc from step #2 into the mine mortar and slide it down flat to the bottom of the tube, so that it rests on top of the black powder. Do not glue the disk. The disc should fit tight enough that it would not slide out if the mortar tube were turned upside down. Also, little or no black powder should leak out through the small holes in the disc if the mortar is inverted over a sheet of paper. The purpose of the disc is to ensure that that the black powder remains at the very bottom of the mortar, separate from the firework stars.
- Measure out about 1/4 cup of firework stars to start, and place them in the mine mortar on top of the perforated disc. For a mortar of this size (2 inch diameter), small firework stars, 1/4" to 5/16" diameter are preferable, in order to prevent a thin or sparse pattern.
- Finally, slide a solid cardboard disc down flat in the mine mortar to hold the firework stars in place. If the mine tube is inverted, the disc should be tight enough to prevent the contents from dropping out. Do not glue the disk.
- Go outside and fire the device. Note the height and density of the firework star pattern. If it looks too sparse, increase the amount of firework stars slightly or decrease the black powder lift slightly. If the firework stars start to turn over and come back down, use more lift or smaller firework stars. Keep careful notes on quantities used for each size and type of mine constructed.
ADDING INSERTS WITH FIREWORK STARS
- The next step after getting a single-color firework star mine to work to your satisfaction is to try adding some simple sound or report inserts. Firecrackers are probably the easiest and can be simply loaded in loose on top of the firework stars. However, a better method which results in more firecrackers getting lit, is to bundle the loose firecrackers together with a rubber band until you have a bunch that is slightly less in diameter than the I.D. of your mine mortar. Insert the bundle, fuses down, into the mine tube on top of the firework stars. There should be no disk between the firework stars and the firecrackers. Slide down an unperforated disc to hold everything in place.
- Other inserts to try are crackling firework stars (dragon eggs), whistles, bees, small serpents, jumping jacks or combinations of these.
LAYERED PATTERN EFFECTS
- Beautiful layered firework star patterns in which groups of firework stars arrange themselves in tiers are easily produced in mines. The only requirement is that firework stars of different shape and density be available. The layering is produced not by carefully arranging the firework stars in some particular order in the mine mortar, but by making use of the aerodynamic properties of various types of firework stars. Round firework stars, for instance, will tend to travel higher than cut firework stars and therefore will appear to separate and rise above the cut firework stars as they exit the mortar. Similarly, higher density, heavier firework stars such as color firework stars will travel higher than lightweight firework stars such as glitter firework stars.
- The greatest layering effect will be achieved by using heavy, dense, round firework stars and lightweight cut firework stars. Imagine throwing a golf ball and a Styrofoam cube up into the air at the same time. Obviously the golf ball will go much higher than the cube. The principle is the same with actual firework stars exiting the mine mortar as the effects of air resistance and momentum cause the firework stars to separate and form a layered pattern. It is immaterial as to the order the firework stars are loaded into the mortar. Two and three layers can be achieved by careful selection of firework star types. Again, do not use a disk between layers.
- Combinations of inserts as suggested in steps 9 and 10 can be added to layered firework star patterns. However, don't overdo the combinations of colors and effects, as the overall look in the air can easily get too busy and confusing.
USING COLOR CHANGING FIREWORK STARS
- An alternate method of producing a layered look is to use round firework stars that change colors two or more times. As the firework stars leave the mine mortar tube they will be visible first as one color for the lower portion of their flight and then suddenly change to one or more different colors higher up in the sky. Visually the effect is somewhat different than the layering method described in steps 11 and 12.
- Color changing firework stars made with a dark burning composition between colors give a very distinct rich looking pattern in the air as they first appear low to the ground, then seem to disappear half way up and suddenly reappear further up in the sky.
- Again, don't forget to experiment with combinations of sound and noise along with color changers.
COMET AND FIREWORK STAR COMBINATIONS
- A very nice effect is a mine utilizing large comets and firework stars. In order not to overload the cardboard mortars, use comets whose thickness is roughly 1/2 their diameter. For this effect the comet should be just slightly less in diameter than the I.D. of the mortar. It should fall loosely into the mine mortar tube. Typically, the comet would be one displaying a long glitter tail for best effect, especially when used in combination with small color firework stars.
- Loading order is as follows: Black powder, perforated disc, small color firework stars (1/4" to 3/8"), comet and solid disk. It is important to place the small firework stars under the comet and not on top, in order for the firework stars to light reliably.
- When fired, the mine will display a low-level cloud of color with a large tailed comet rising up through the center of the cloud and continuing to a higher elevation.
SOME FINAL THOUGHTS
- Mines are a great way to enhance any type of pyrotechnic display. They are surprisingly effective even in small sizes, and require a minimum of materials. Keep in mind that mines are much more impressive when fired in multiples rather than merely sizing up a single mine. Six or eight 2 1/2" mines placed 35 feet apart in a straight line and fired simultaneously will get much more response from your audience than one or two 6" mines.
- Make sure you first thoroughly understand the principles of constructing mines in smaller sizes (1 1/2" to 2" tube I.D.) before trying to scale up to larger sizes. I have seen mortar tubes (HDPE) blown apart by people that thought that mine construction consisted simply of pouring firework stars and black powder in a tube and lighting the fuse. Large diameter mines can be very dangerous if improperly made. There are very few instances where mines over 4" I.D. are necessary or justified, especially when fired in multiples.
FREQUENTLY ASKED QUESTIONS
Q: Do mines always have to be fired straight up?
A: No, fan shaped or angled arrays are a great variation. "V" shaped patterns of mines augmented with mortars firing tailed artillery shells straight up works very nicely. Layered mines containing comets whose effect matches the tail of rising shells are beautiful.
Q: Do I have to use 2FA Black Powder?
A: No, especially on small mines (1" to 2" I.D.), 4FA works fine. However, with smaller particle black powder there is more chance that the powder will migrate through the holes in the perforated disc and mix in with the firework stars. To prevent this, a piece of tissue paper can be lightly glued to the underside of the perforated disc.
Q: What is the best way to construct electrically fired mines?
A: Look up the article on making multi-shot boards. Go to the section on inserting electric matches in disposable mortar tubes. Do not attempt to load mines with a live electric match at the bottom of the mortar, unless the match has a shroud over its head. Always use extreme caution when using electric matches, THEY ARE VERY IMPACT AND FRICTION SENSITIVE!
Q: How much material can I put into any single mine tube?
A: Donít fill cardboard tubes any more than 1/3 full with all mine contents including black powder, firework stars, comets, and inserts. If you do, the mine is likely to explode when ignited.
Q: I have heard that building up alternating layers of black powder and firework stars makes layered mines, similar in fashion to the method used for making double and triple petal shells. Will this work?
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