6 replies to this topic

[parabolic]

Hi,

This is more related to battle field pyrotechnics--and paintball etc...

Iam also aware of the thread 'phosphorus' which doesnt answer my following question.

I recently used a 'mk9 thunderflash' made by spectrum,, It had a removable top striker surface, slow 1/4 time fuse with a strike compound stuck to the end. I asume it was made with flash powder.

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

Having looked up 'saftey match' on Wikipedia and if you dont mind please read..


"safety match was invented in 1844 by the Swede Gustaf Erik Pasch and improved by John Edvard Lundstr?m a decade later.

Their safety is due to the separation of the combustible ingredients between the match head and a special striking surface, and the replacement of white phosphorus with red phosphorus. The striking surface is composed of powdered glass and red phosphorus, and the match head was composed of antimony(III) sulfide and potassium chlorate. The act of striking converts some of the red phosphorus to white by friction heat. The small amount of white phosphorus then ignites, and this starts the combustion of the match head."

so, it sounds like the striker surface on the 'spectrum mk9 thunderflash' was powdered glass and red phosphorus...,

Iam NOT intrested in making the striker part that contains the phosphorus. there are issues regarding this....so I intend to keep used strikers from old items, and use them as striker material on my own new devices "its called recycling "

I AM intrested in the actual strike composition that is on the fuse, "antimony(III) sulfide and potassium chlorate"

what id like to know, has anyone tried this and what can you give me advice on. or if be, any other alternative to this method of ignition?. 'antimony(III) sulfide' sounds hard to come by.

Para

Edited by parabolic, 16 October 2006 - 05:51 PM.

[EnigmaticBiker]

what id like to know, has anyone tried this and what can you give me advice on. or if be, any other alternative to this method of ignition?. 'antimony(III) sulfide' sounds hard to come by.

Para

Striker fuses aren't really used much in fireworks.

Mixing Antimony (III) sulphide (often called Antimony trisulphide) with any chlorate is not a safe operation, problems similar to sulphur/chlorate mixtures (There are lots of searchable posts on that subject).

The match manufacturers probably stabilise their formulation with other additives.

It isn't cheap, Stibnite is one source.

A simple solution might be to use a "bengal" match as part of a fuse but I've not used it myself.

Edited by EnigmaticBiker, 16 October 2006 - 09:17 PM.

[Asteroid]

From the pyro database - Only no2 is any real use, I think MnO2 is poisonous.

some other ideas could be (not all necessarily practical)
KMnO4 in a thin tube, and a container with glycerin elsewhere the thin tube is connected to the fuse.
Existing match heads attached to the fuse, which means the same striker can still be used.
Wires from a low-current ematch sticking out, fired with a portable battery pack (maybe a few batteries wired to the same electrodes) the electrodes are touched to the wires and it fires.

Edited by Asteroid, 17 October 2006 - 04:02 PM.

[adamw]

The actual formulation of the striker composition is potassium chlorate and resin (without being too specific)

[parabolic]

Just managed to get hold of some stibnite rock,

I ground some up and tried the 'Clark scratch ignitor part 1'.

works a treat!!.

Para

[aapua]

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

[d3v]

thanks for the info but where can you get potassium chlorate from in the UK?