633 replies to this topic

[Stuart]

http://www.ukrocketr....php?act=Search is the link you want to search the whole forum, the one above will only search the Pyrotechnic formula forum.

Edited by Stuart, 14 June 2006 - 02:16 PM.

[Pyromaster2003]

What stars can be made to ignite and not shatter when used in a flash based aerial maroon? I opened an air b*mb a few years ago and it contained flash with small 4-5 mm stars. I have never seen a formula for these or heard anything about them so if anyone knows how they are made i would like to hear. Thanks, Chris

[Creepin_pyro]

I would think most organic/metallic fuelled colour stars would be able to wishstand a flash burst without shattering. The properties you may actually be looking for would be slow burning (as they're typically very small microstars) and ability to take fire from a flash burst, which will be dependant on priming. As long as they're bound well, you shouldn't have any issues with shattering.

[starseeker]

Hi everybody,
now that we have the cold and damp weather creeping in my workshop is getting a bit damp so haveing probs drying my comps Any suggestings on speeding the process up apart from putting heating in my workshop! Cheers.

[Mortartube]

Put any stars you are drying into a sieve that is supported on some wooden blocks, this will allow a better airflow and assist in drying times.

[Phoenix]

One method I used for drying stuff in winter, before I built a drying cupboard was as follows: Allow the stars etc. to get as dry as possible in the open air (unless something's particularly hygroscopic it will dry out reasonably well eventually) and then to seal them up in a plastic bucket with some dry magnesium sulphate (Epsom salts baked in the oven - can of course be reused) and leave them to finish drying in there. Takes a while, but it does do the job.

A posher version of the Epsom salts would be a miniature dehumidifier - remember seeing them. Thye're basically just a box of dessicant with a heater that allows you to recharge them, and a fan to circulate air through it - about £10-20, IIRC.

[adamw]

Just get one of those 'moisture traps' which are basicaly calcium chloride (hydroscopic) crystals suspended over a tray

[starseeker]

Just get one of those 'moisture traps' which are basicaly calcium chloride (hydroscopic) crystals suspended over a tray

Cheers everybody,
i will give a couple of these idea a go with my batch of glitter stars i have just finnished

[StarScream]

Note that today, true "white stars" are credited for the metallic addition of Magnesium, or the organic (more common) inclusion of antimony trisulphide. You can also use Antinomy Metal powder. Formulas containing KNO3, Sulphur, and Antinomy will burn with a brilliant white much better then the white posted in the quote.

For Example:

Davis:
KNO3: 62
Antinomy (III) sulphide: 17
Sulfur: 17
Dextrin: 3

Working many years with white formulas that utilize KN03, S and C (with or without AL), I had to redefine my understanding of ?White? after using Devis formula.

Does anyone know what prime to use for these Davis white stars? Meal priming doesn't seem to be enough to get them going. Maybe meal with a few percent bright flake Al added?

[Mumbles]

That should light relatively easy with all that sulfur. BP with 5% or so aluminum should probably do it. If that does not work, try a step prime. a 50/50 mix of the star mix with BP, then a layer of BP.

[hoarp001]

Hi, I just finished pressing around 80 stars using this comp (8x8mm, cylindrical):

white star
Potassium nitrate 59%
Sulfur 30%
black powder 11%

(found on post 16 on this thread, second page)

I tried to light the powdered comp on a spoon, but it took a while to take, the high sulphur seemed to boil and release rather nasty fumes before burning. It also burns very slowly. A 1g ammount in an open tube lit with some visco (burnt immediatly) took about 4 seconds to burn. It does burn with a bright white light but im worried that when the stars dry, they wont ignite when fired from candles, mines and shells. Karl suggested that I prime the stars by wetting them and then rolling them around in a meal powder and dextrin comp to coat the stars in BP.

Will this work, or will the BP coat just burn off and leave the star flying unlit?

Thanks for any help.

[karlfoxman]

If they still refuse to light with bp prime then use a hotter prime by adding fine metal into the prime, something like 5-10% should be ok. Also you could try using a bp prime with 20-45% of the original star formula. These primes are often used on Veline stars and give great results!

Edited by karlfoxman, 01 December 2006 - 12:41 PM.

[hoarp001]

Ok, I will give it a go...

When i stood one dry star in a little pile of black powder, the powder burnt but the star was untouched!

[seymour]

Those stars need to be very dry to work, and a BP prime does light them.

[Deafaid]

Hi!
I'm new here....but I've been doing pyrotechnics for about two years.
I'm wondering if its possible to replace parlon with pvc in this formula:

Veline blue

potassium perchlorate 55%
parlon 15%
red gum 9%
mg/al 6%
dextrin 4%
copper(II)oxide 15%

Edited by Deafaid, 12 December 2006 - 10:46 AM.