Behavior of charcoal star on ground

[Zumber]

hello APC,

recently i have purchesed 3 inch cake from local pyrotechnician and fired it,the effect was awesome like coconut tree.I really liked it and then i went to him and asked for formula but he just refused to answer due to tough compition between them.then i purchesed another one cake and opened it then tested his star.

Now story is...

The star was 2mm when ignited burned within 1 sec throught the center without any tail and left a red hot ball for 5 to 6 sec which is obviously due to high charcoal content. I guess when such red hot ball travells at high speed heavy wind resistance will facilitate escaping red hot charcoal sparks from outer surface to center which will creat a tailed path.

Now question is...

1)Whether willow star behaves like that on ground?

2)what kind of those stars i am trying to explain?

[AlexPyro66]

The star burned with a orange or with a gold color can you post a video with the star on a star gun?

[Arthur]

Most charcoal stars are formulated to need the air that they are flying through, the "red hot ball" would normally have burned in the air and probably become the tail.

 

Tiger Tail - a charcoal star- is equal parts of charcoal and nitrate. BP has about five times as much nitrate as carbon, TT is a slow star, the different proportions make BP a fast propellant.

[Zumber]

alexpyro star burned with yellow fire...

I will post video in a day or two.

[Zumber]

arthur totally agreed.

But his star weren't TT as his star brocades and comes to ground like willow.

[Seymour]

It is likely then to have a similar chacoal to Potassium nitrate ratio to Tigertail but with Titanium or Ferrotitanium added, and probably a higher sulfur content, which I believe adds to the twinkly nature of the classic brocade.

 

Relatively minor modifications of things like charcoal content, metal particle size, charcoal type, and processing methods can have quite major effects on the burn speed and hang time. From the sounds of what you are describing, I would say that the metal and charcoal content is at the higher end of the spectrum.

 

Look at a formula like "Slow gold", except since the stars are so small, the metal content is probably better at 15 to 20% instead of the 7% (IIRC) in the original formula.

[a_bab]

You can analize the star yourself, instead of guessing. All you need is a microscope (there are some really cheap pocket microscopes nowadays, they cost under 5 bucks). Then you need a balance (I'm sure you already have that) and some smart approach.

 

1. Disolving the star in water, filtering the leftover fuels, drying and weighting them will tell you the nitrate content. There are reagents for finding the nitrate ion, or perc/chlorate. It may be possible in such a star.

2. On microscope you can see the particles, the experience in this case can tell you what charcoal/what metal is in there.

3. Treating the fuel with acetone will remove sulphur and some organic binders (but I'm sure your star is water based, most likely bound with SRGS - really important for charcoal stars)

[AlexPyro66]

Most pyrotechnic companies use black powder as a base and they add other metals for the effect

[Zumber]

m.youtube.com/watch?hl=en-GB&gl=GB&client=mv-google&v=NrQp37AMRds&fulldescription=1

his star test on ground.

[Zumber]

first thanks a lot seymour, alexpyro and a_bab...

I will definately give a try on TT with higher sulfer content but how much high would it be seymour? I will follow TT composition with 44/44/20 KNO3/C/sulfer ratio.

Thanks for the analytical method a_bab.

I have a question

1) sulfer is very minor soluable in acetone so its difficult to seperate from charcoal.

But it is very soluable in toluene which is very fancy to me

2) if he has used a prime for his star then this prime will introduce error.

Afterall thanks a lot to all

i will find it by trial and error.

[AlexPyro66]

Try this composition Kno3.........................54

charcoal airfloat........20

charcoal 60-mesh.....20

sulphur......................8

dextrin.......................+7

I think it is better to cut those stars(this comp is a modified c8 total parts are 109)

Edited January 18, 2013 by AlexPyro66

[Zumber]

okay...

What kind of charcoal?

Whats the effect?

[a_bab]

You are right about sulphur, it won't disolve in acetone well enough. I actually thought about that when I wrote it - well, let's call it a brainfart.

As about the prime, there's a high chance the star is unprimed - being BP based. Cutting the star in half will show you if there is a prime layer or not - the difference is very visible usually.

[Zumber]

Ohh..!! I am satisfied enough with your answer.

Afterall thanks a lot..:-)

[AlexPyro66]

okay...

What kind of charcoal?

Whats the effect?

Any type of hardwood will be ok when i make high charcoal stars i use a mix of pine and bbq

[Mumbles]

Acetone might work for a small scale extraction like this. It's not extremely soluble, but on a small sample only a moderate amount of acetone in theory is required.

 

This reference states that the solubility is about on par with that of benzene, around 2.7% w/w. http://www.gps.caltech.edu/~vijay/Papers/Chemistry/Meyer-76.pdf

[Zumber]

what are you talking about mumbles??seperation of sulfer from charcoal using acetone??

[AirCowPeacock]

I know sulfur has high soubility boiling Xylene, but I suppose that's not neccicary. I didn't think sulfur would have reasonable solubility in acetone.