aapua

To mostly Shrubsole and fishy1.

I've done some research works with the "idea no. 1". I guess that the slow results with the 1st attempt were simply caused by bad mixing of chemicals.

KClO4 70, C 18, S 12 + 5-10% AlDarkPyro + 5% Dextrin works very well.

As i already mentioned there a huge varieties of foams. As I would say the best results are with the ones with "open pores". The point is that it sucks in all the paste or soup, after drying it actually gets back its old form - its a foam again. It is clearly seen when you cut the dry pieces into thin slices - it has like it was, foam, the dried mixture stays as a thin layer everywhere in it. So, instead of forming a solid star, it actually has a huge reaction surface, and the actual weight of burst charge will be therefore much less.

Anyway, just one alternative possibility in my mind.

Well, about the price - depends what is expensive and what's cheap. Blue and green - as I said it just took some days of playing, but I got these. For the blue I used ammonium perc as the main oxidizer, plus some CuO and Cu acetate, again with hexamine. By adding some Barium perchlorate the colour gets deeper. Green bases on only barium perchlorate or its mixture with AP, I can put here the compositions tomorrow, because I'm home now.

Note. The cheapest price is not my purpose - as cheap as the chinese fireworks is it never will be anyway, what I try to do, is to get colours even better, the effects last longer etc.

You can add both acetone or better methylated spirt to the glue.

Mortartube - do you know what was the company made these rockets? These flat stars are very interesting.

It depends on the time you keep the material in the "soup". When the time is short enough, the mixture stays only in the outer pores and doesn't go in. So it doesn't form a "star". Again, there are huge variety of different materials, I chose the one with pretty small pores. The result is just coated pieces.

Iam really quite intrested in making this strike compostition so that I can use it for smoke devices./ or perhaps my own thunder flash.

Hello,

first, the mixture of anthimony(III)sulphide/chlorate is pretty common, and it's quite safe. Depending on what glue to use (not PVA!!!), use ratio 1:2 or 1:3, then add 5-15 % of glue. Water-based glue is safer, but NC is commonly used as well. NOTE. Avoid scratching dried mixture and work with great care.

The main reason to write was your idea of making your own thunderflash. I'm not gonna cool you down, just there are few things to be followed in order to get a safe product.

In Estonia we've had several accidents with self-made thunderflashed whithin past few years. Lost fingers are the most common result of this. With the company where I work we have designed pretty many different types of thunderflashes.

1. Use only friction-type igniters. Fly-off or pulling igniters look more attractive but will cause you several safety problems.

2. Use closed safety fuse, with standard burning rate (1 cm per sec). Good diameter of fuse would be 5-6 mm. Like WANO of Germany or Kik-Kamnik of Slovenia. It's very hard to fully control the burning rate of open-flame fuse, especially when going through the "collars".

3. Don't use fuse shorter than 6 cm, together with the prime it gives you the delay of appr. 7 sec.

4. Separate the flash and the match head as far as possible - never use just one cardboard disc for that purpose. Create an empty chamber appr. 3-4 cm long with discs on both ends. This will guarantee that the first seconds of burning the flame can't contact with the flash (fuse damages, etc). Good idea is to use cork for that purpose as well, preffer agglomerated, not natural cork. Deffinitely glue both ends of fuse/cork or discs. Very important is that the fuse must fit into the holes of discs or cork very tightly. When shaking the thunderflash (in transportation, for example), the flash may come through the same hole where the fuse is. The result is that it has no delay anymore. You probably don't want this? And also, try to make this separating chamber as light as possible - when bursting, the heavy details will fly as shrapnels, depending on how much powder you have, the flight might be some 25-30 meters!!!

5. Choose only the best glue to glue fuse and discs together. For the silicon-coated fuse the best choice would be Henkel's SuperMoment, or similar polyacrylate. For the plastic-coated, like WANO, use HotMelt. Note. I've tested ca. 7-10 different types of HotMelts, and only 2 of them do the job. Remember - it is critical to glue the fuse in its holder so well that nothing can come through.

As you see - all these points are about the delay element. If you fail with this, you'll get hurt.

Basicly - cut the fuse, dip one end into the matchhead composition, push the fuse through the collar, glue both ends, dip another end of the fuse into a priming mixture (whatever mixture, the same matchhead mixture would do fine) to guarantee the flash to work and leave it dry. Take a tube you planned as the thunderflash body, glue the disc into one end as the closing disc, fill the tube with some amount of flash, take the dried delay element and insert it into the handle. Buy a box of matches if you don't want to make your own friction mixture - but better not. Red phosphorus is not a good thing to handle. And - ready to go.

Good luck to ya,
and play safe.

Aapua

Where did you you find out about Red P forming White P, that is something i have not heard of before and i would like to research it for myself, of course i'll search for information on my own but a particular source of information is always handy.

basicly, at university we made "shows" where small amount of red P was put into a long and narrow glass tube, then ignited. The walls then covered with white P (very easy to observe) whitch started to glow. Pretty beautiful, though poisonous.

The fenomena of transformation of red P into a white one by scratching is well known in match chemistry (actually I started as a match-pyrotechnican chemist years ago). The red phosphorus matches ignition is explained as a minor amount of red P from the surface of a match box turns into a white one when scratched; this, plus small amount of red (or white, I don't know exactly) phosphorus being in contact with potassium chlorate in match head cause match head ignition. I believe Swedish Match must have done very good researches in that subject, about their availability... hmmm, not very sure.

The best way to see the formation of white P is just to take, say, a tablespoon of red P, then ignite. Let it burn (actually glow) for a while, then blow off the flame. You'll see spots of white P still glowing, all the stuff doesn't catch fire anymore, it just smokes and glows (the ignition temperature of white P is very low - if I'm not compleately wrong, then somwhere around 40 degrees).