10 replies to this topic

[Maxim]

Extra bright torch
Source: rec.pyrotechnics
Comments: According to the original text: "An aluminum torch of heretofore unheard of
brilliance and giving an illumination, in the 2.54cm size, of what is said to be 100000
candlepower". Testing with paint grade aluminum revealed that it burns very bright
indeed at a steady slow burnrate and with little residue. It is easily pressed in tubes.
Preparation: Rub the Vaseline into the barium nitrate. Mix the sulfur and the aluminum
separately. Then mix it with the barium nitrate/vaseline mixture. A starting fire mixture is
required for ignition. The ’starting fire #1’ composition can be used for that purpose.
Barium nitrate....................................38
Mixed Aluminum....................................9
Sulfur............................................2
Vaseline..........................................1

Having tested it, I have to warn you, you may have to look away - its that bright!

Question for the pros - what is its suitability for use in stars if a binder is introduced?

http://www.youtube.c...h?v=mwPQOLEtzsQ

Edited by Maxim, 15 January 2011 - 12:53 PM.

[dr thrust]

great video maxim!,
the formula is originally from weingarts book.
ive made it myself and was equally impressed by the light output
as its suitability as a star formula.. im thinking its been tweaked to be a slow burning flare comp, so you'd, loose the Vaseline, and add a little k perc to speed up the burn rate

[Maxim]

Ill try that one, but ill have to be careful not to accidentally formulate a type of flash powder...

For anyone that is wondering why vaseline is used, i tried using it without vaseline and found that the flare amasses a tendency to strobe (and often burn out with plenty of composition left) so never forget about the vaseline!

Does anyone know of any even brighter formulae? Would slowing down any flash powders create a brighter effect?

I am aware that the brightness level is like the physics of softening a fall, the longer you prolong the impact of the fall, the "softer" it is. So thats why flash powder are so bright - they explode (burn at hundredths of a second) and all of the energy is released quickly and that is why it is so bright. Slow down the burn rate and the same amount of fuel will release energy slower, making it less bright.

[BrightStar]

For anyone that is wondering why vaseline is used, i tried using it without vaseline and found that the flare amasses a tendency to strobe

Interesting that the vaseline stabilises the burn. I've had Nitrate/Sulfur/Al flare mixes burn very erratically in the past and this might be a trick to explore.

One formula I often see quoted for a bright flare is:

Potassium Perchlorate 30%
Barium Nitrate 30%
Aluminium Powder 40%

I have no idea of the original source and haven't tested it myself. Given that it contains twice as much Al as the formula above it may well be brighter. As you point out though, in powder form it's essentially flash so probably rather hazardous.

[Maxim]

Potassium Perchlorate 30%
Barium Nitrate 30%
Aluminium Powder 40%

Thats basically 60% oxidizer and 40% fuel... common flash is 70% ox to 30% fuel

The bright flare is about 80% ox and 20% fuel WITH vaseline that slows it down somewhat...

Your formula looks like it could work though, ill give it a go, taking as much care as i would with flash power initially for a burn test.

[dr thrust]

as well as Vaseline, which acts as a desensitizer in the flare comp, so it doesn't act as flash, there has been other things used for the same purpose, ie, boiled linseed oil, Castor oil,even paraffin wax shavings, you'll find plenty of info on flares in this thread
magnesium flares

Edited by dr thrust, 16 January 2011 - 11:01 PM.

[Creepin_pyro]

Nice flare!

In terms of modifying this formula for stars, I wouldn't bother. There are plenty of white/illumination stars which are already tried and tested. Luce Forte comes to mind. Here's an example (there are a few variations) from rec.pyro:

24 lb. barium nitrate
8 lb. #809 aluminum
3 lb. saltpetre
2 lb. sulphur
2 lb. dextrine

Replace the saltpetre with cryolite for a 'gold mag' effect.

And a few more from the PFP.

If you really want a brighter flare, you could look into NaNO3/Mg flares... silly bright. I wouldn't advise making them unless you're very familiar with the hazards of working with Mg and hygroscopic oxidisers though.

[Maxim]

Lol i hear sodium nitrate can be worse than barium nitrate in terms of being hygroscopic!

[Mumbles]

If your barium nitrate is hygroscopic, you must have some impure chemicals. Are you sure you're not thinking of strontium nitrate? Even the pure form of that isn't very hygroscopic, but any tiny amount of SrCl2 makes it suck up water like a sponge.

[Maxim]

Well my barium nitrate is basically a solid lump of rock, i have to smash it with a hammer and then put it in a blender with Cab-o-sil to make it stay as a powder.

[Mumbles]

Clumping is not necessarily the same as being hygroscopic. KNO3 and potassium perchlorate cake too, but don't chemically absorb water.

I wouldn't be so confident with a 60:40 mix of oxidizer and fuel not being a flash powder. I frequently use a mix of that type as a slow flash to break shells.

BTW, if your nitrate/Al/S stars strobe or don't burn consistently, adding up to a few parts of charcoal can help to smooth the burn out.