Waterfall

Three tube waterfall

A waterfall is type of firework that is hung upside down by string or mounted to a structure or rope. The composition, when lit produces an effect of long lasting silver sparks which cascade to the ground, thus giving the appearance of a waterfall. To successfully create this effect the waterfall tubes are placed close together (normally about 25 cm apart), in great numbers and high off the ground. Depending on the size of the tubes and the granularity of the aluminium in the composition, the sparks can fall up to 30 feet. All of the tubes must be ignited at the same time and this is normally achieved with the use of a quick match, which is an extremely fast burning fuse. If the waterfall is hung with string, it allows the tubes to swing back and forth when burning which enhances the effect and glamour of the waterfall.

[edit] Tutorial

Composition
There are many variations of waterfall composition that can be used and possibly the most common is composition 1, however if you do not have access to potassium perchlorate then composition 2 which uses potassium nitrate as the oxidizer is the better option.

[edit] Materials

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Casing
A thin paper tube is used as a casing, which can either be bought, or as in this example you can use ordinary A4 (or 8-1/2" x 11") paper. The casing must burn away with the composition if the waterfall is to function properly. Under no circumstances be tempted to use materials other than paper, it is dangerous and unnecessary.

Tools
Wooden dowel, mixing cups and sticks, digital scales, sticky tape, isopropyl alcohol and water.

Prime
A small amount of black powder (meal powder) and waterfall composition will need to be mixed together and used as prime to assist in ignition at effect time.

[edit] Construction

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First step is making your tubes and deciding how large a waterfall display you are going to make. Remember the larger the tube and bigger the display the more composition you are going to need, and this can be expensive. As a general rule a waterfall display should be no less than 3-4 tubes. Cut your A4 paper in half length ways. Each piece of A4 paper will make two tubes so if you plan to make numerous tubes it's a good idea to cut several sheets at once.

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To make the tube simply roll the paper around the length of your wooden dowel. It is important that you don't wrap it too tight as it will make difficult to slide off the dowel and also pack the composition into later as we will be using the same length of dowel. Once you have finished rolling the paper secure the edge down with a length of sticky tape. Continue doing this until you have the desired number of tubes.

Composition

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Grind all chemicals as fine as possible except for the aluminium. This can be done for instance using a coffee grinder or mortar and pestle. Screen the chemicals together by passing the mixture several times through a mesh screen. The function of the dextrin is to act as adhesive and bind the composition together, eventually hardening it into a solid mass once it is dry. Mix up a solution of about 75% water and 25% isopropyl alcohol (do not add any more than 25% alcohol as it will reduce the adhesive properties of the dextrin). The alcohol makes the water wetter by breaking down the surface tension of the composition and allows the water to be absorbed easier. The drying time of a composition is also reduced as alcohol evaporates faster than water. Add some of the solution to the composition and mix well. Keep adding until it is damp enough to clump together if you squeezed an amount in your hand. Don't make the mixture too wet or it will make pumping impossible. If this happens, just add more dry mix.

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Take one of the tubes and stand it upright on a solid surface for example a piece of wood. Using a mixing stick take a small amount of composition and add it to the tube. Press it down the tube firmly with your wooden dowel. Only add as much composition that will give you about the thickness of the inner diameter of the tube. If you add too much it may not consolidate evenly and can cause your firework to fail. You will also be able to add more composition into the tube if it is added in small increments and pressed correctly.

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Continue filling and pressing the tube until it is about 1/2 cm from the top. We now need to make some priming composition that is needed to ignite the waterfall composition that on its own is very difficult to ignite. A fuse will not be able to generate the heat required to start the waterfall composition burning.

Priming

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Mix 10 grams of waterfall composition and 2 grams of meal powder together and dampen slightly as before. Press this into the remaining space at the end of the tube. Black match or visco fuse can now be inserted into the prime. Once you have finished all of your tubes allow them dry for about 3-5 days, however this composition will still burn well if damp. All that remains is assembling your waterfall and connecting your quick match etc.

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If you do not have access to quick match and are doing a small display you can use varying lengths of visco fuse. Ignite the longest first and shortest last, that way you should be able to ignite all the tubes at the same time. You can use a hot glue gun to secure the waterfall tubes to the horizontal bar.

[edit] Video

3 tube waterfall - 1631kb - In this example the 3 tube waterfall burnt for over 1 minute (this video is 18 second segment)..