Igniting stars inside shell

[Jordan123]

Hi everybody !

 

Today i'm asking about the ignite of the stars this is for me the most complicated step for made firework.

So, i would know your view about this :

 

A shell who is wrapped better, stronger than an other one is she ignite most correctly ?

 

 

I thought than when the time fuse fire on the indoor of the shell the rice hulls coated with bp (or other stuff) ignite better the stars and other pyrotechnics stuff when the break is most diffcult.

In fact, a quickly break would have no time to fire all pyrotechnics stuff.

This thinking is because i use some good method of priming my stars and sometimes stars as not all ignite.

[Arthur]

A shell that bursts too easily is one possible cause of ignition failure. Are you trying to use plastic hemis or paper ones?

[OldMarine]

Good containment allows the flame to spread all through the shell before the case ruptures. This helps insure all sides of the star have taken fire before then and that means better ignition. I asked Mike Swisher about this a while back and will post his explanation of the inner working of a shell as soon as I can find it.

[braddsn]

Proper pasting is very important, but in my opinion... for reasons other than star ignition. Some shells (like horsetail shells) can be made with very little pasting, and the stars all ignite perfectly. Also starmines certainly don't have 8 layers of tape, and the stars light great. Star ignition is all about PRIMING. Prime the stars properly and you will always have 100% ignition. Use a prime that takes fire easily, and contains black iron oxide or silicon in order to create molten slag on the star so that it won't blow out at high speed. The black iron oxide and silicon become more important if the star is going to be travelling at high speed (hard breaking shell). I suggest monocapa prime, it is a great all around prime. You could also use bp+silicon. My bet is that most people that have ignition problems aren't using enough prime. IF you have a star that is improperly primed, then it won't matter how many layers you paste on the shell, you won't get ignition. Good luck!

[Sulphurstan]

Jordan.

Couple of months ago, I read an article in the literature (AFN news? elsewhere? sorry, cannot remember!), where this duality (hard / low break, high / low confinement etc.) was clearly discussed.

What I could remember, is just to confirm what has been exposed before:

- Good confinement allows the fire to "have time" to fill the shell (and thus "lick" each stars - love that ! [grin]) before the shell breaks. If the shell breaks too easily, the fire "hasn't time" to spread all around, if the shell breaks very hardly, the pressure and the blow may extinguish the stars (even if ignited before), (But with fairly good prime, this situation is unlikely to happen, even with super thick kraft paper pasting!)

- PRIMING is probably even more important (see what braddsn writes about starmines). I also confirm that Monocapa or BP+Si are great

[Wiley]

Fencepost is another good one. Just use any old charcoal. The balsa/cypress/whatever is not necessary. It's the silicon and diatomaceous earth that make it work. I use 50% of the weight of my colored stars in this prime, and I've never had blind stars. I make cylinders, and all colored stars have ignited even from violent flash bag breaks.

[Jordan123]

Thank you so much to give me some informations in order to improve my firework's making

A shell that bursts too easily is one possible cause of ignition failure. Are you trying to use plastic hemis or paper ones?

So it's good to read than my hypothesis was true. I use paper hemis and cylindrical shell with paper.
Plastic stuff is really bad for the nature lot of animals and vegetation was contaminated if we use plastic please respect the nature

Good containment allows the flame to spread all through the shell before the case ruptures. This helps insure all sides of the star have taken fire before then and that means better ignition. I asked Mike Swisher about this a while back and will post his explanation of the inner working of a shell as soon as I can find it.

Great to read this ! so now i focus on a good wrapping/making of my shell or cylindrical firework

Proper pasting is very important, but in my opinion... for reasons other than star ignition. Some shells (like horsetail shells) can be made with very little pasting, and the stars all ignite perfectly. Also starmines certainly don't have 8 layers of tape, and the stars light great. Star ignition is all about PRIMING. Prime the stars properly and you will always have 100% ignition. Use a prime that takes fire easily, and contains black iron oxide or silicon in order to create molten slag on the star so that it won't blow out at high speed. The black iron oxide and silicon become more important if the star is going to be travelling at high speed (hard breaking shell). I suggest monocapa prime, it is a great all around prime. You could also use bp+silicon. My bet is that most people that have ignition problems aren't using enough prime. IF you have a star that is improperly primed, then it won't matter how many layers you paste on the shell, you won't get ignition. Good luck!

Good comparison this true a starmine was not wrapped too much !

I use 2 layers of prime :
-the first "hot ignite prime" (potassium perchlorate 71/Charcoal 14/Red gum 9 /Magnialium)
-and the second a green mix

Can you give me the recipe of the "monocapa prime" ?

Jordan.
Couple of months ago, I read an article in the literature (AFN news? elsewhere? sorry, cannot remember!), where this duality (hard / low break, high / low confinement etc.) was clearly discussed.
What I could remember, is just to confirm what has been exposed before:
- Good confinement allows the fire to "have time" to fill the shell (and thus "lick" each stars - love that ! [grin]) before the shell breaks. If the shell breaks too easily, the fire "hasn't time" to spread all around, if the shell breaks very hardly, the pressure and the blow may extinguish the stars (even if ignited before), (But with fairly good prime, this situation is unlikely to happen, even with super thick kraft paper pasting!)
- PRIMING is probably even more important (see what braddsn writes about starmines). I also confirm that Monocapa or BP+Si are great

Thank you for your contribution i thought the same.

Fencepost is another good one. Just use any old charcoal. The balsa/cypress/whatever is not necessary. It's the silicon and diatomaceous earth that make it work. I use 50% of the weight of my colored stars in this prime, and I've never had blind stars. I make cylinders, and all colored stars have ignited even from violent flash bag breaks.

I don't now the recipe of fencepost.

Edited October 10, 2017 by Jordan123

[PeteyPyro]

Monocapa Prime - from PyroData.com

Potassium Perchlorate 24.6

Potassium Nitrate 31.1

Charcoal. 11.5

Red Gum 4.1

Sulfur 4.9

Iron oxide (black) 7.4

Magnalium 230 mesh 12.3

Dextrin 4.1

Charcoal is airfloat, willow, or Paulownia

Dark aluminum may be substituted for the Magnalium.

[OldMarine]

I agree priming is important but in a shell the stars are flung outward much faster than from a horsetail shell or mine and have less time to develop a surface burn. Unprimed Buttered Popcorn stars work fine from a mine but blow blind in a hard broken 3" ball shell i my experience anyway. I prime the heck out of everything with monocapa regardless now and make sure I have my shell casing built up plenty as well. Just got into ball shells and I want them to succeed!

[Jordan123]

I'm totaly agree with you of course you have reason a starmine the stars have more time to be ignite than a break into a shell ! It's a good point.

 

Thank for the recipe i try this when i make new batch of stars

Edited October 11, 2017 by Jordan123

[Wiley]

A search for "Fence Post" revealed the following: https://www.amateurpyro.com/forums/topic/9858-fence-post-prime-question/?fromsearch=1

[pyrojig]

I too use the ,monocopa prime , agree it is better to prime well than not. I enjoy a hard broken shell . And priming is a need for this , it is cheap insurance and a minimal step to insure all your hard work is not going to waste . Since using this formulation I have yet to to have a blind star. So I too chime in on star priming as a critical step. I have seen commercial cake shells broke on just whistle /or flash, and the stars take fire well because of sufficient priming

[Arthur]

The design for a shell is as important as it is detailed. Getting the ingredients list is only part of making stars so putting stars in hemis is only part of making shells.

 

The hemis that you use influence the break style that is most suitable to make the shape that you want and the prime style depends on the break style and the star type and formula. Far too many aspects of shell design are interlinked for designs to work perfectly without tests.

[Jordan123]

I too use the ,monocopa prime , agree it is better to prime well than not. I enjoy a hard broken shell . And priming is a need for this , it is cheap insurance and a minimal step to insure all your hard work is not going to waste . Since using this formulation I have yet to to have a blind star. So I too chime in on star priming as a critical step. I have seen commercial cake shells broke on just whistle /or flash, and the stars take fire well because of sufficient priming

Incredible, just with the break !

 

The design for a shell is as important as it is detailed. Getting the ingredients list is only part of making stars so putting stars in hemis is only part of making shells.

 

The hemis that you use influence the break style that is most suitable to make the shape that you want and the prime style depends on the break style and the star type and formula. Far too many aspects of shell design are interlinked for designs to work perfectly without tests.

Of course, it's difficul for me to have a nice break, today i have shoot my first cylindrical shell since 2-3 years because before i haven't time to spend time on my hobbies...

And that's the result, i'm sad poor break i would a nice spherical effect

[OldMarine]

Did you have the shell spiked well? Seemed to be a lazy burst due to improper containment rather than weak burst.

[braddsn]

It looks like many of your stars did not ignite. In order to get a symmetrical break, the most important factor is star ignition, and this is achieved by proper priming. It took me 2 years to finally get my priming dialed in and consistent.

 

https://youtu.be/19_owFBl9LQ?t=3s

[Jordan123]

Did you have the shell spiked well? Seemed to be a lazy burst due to improper containment rather than weak burst.

Yes, i have spiked my shell and wrapped again with may layer of paper. But you have probably reason i think the containement is not well...

It's one of first shell which i made my own cylindrical paper container, before i use cylindrical papaer already made ad with a big thickness + there end paper disck

 

 

 

 

It looks like many of your stars did not ignite. In order to get a symmetrical break, the most important factor is star ignition, and this is achieved by proper priming. It took me 2 years to finally get my priming dialed in and consistent.

 

https://youtu.be/19_owFBl9LQ?t=3s

yes i thought it's one of the problems .... but my stars are coated by a hot prime and last layer is BP green mix but that is not enough i'm really sad and don't know how i can resolve the stars priming problem...

How do you prime your stars ?

I would use the Monocapa Prime in the future stars's making

Really nice shell, i love ! a very nice break and prime

Edited October 16, 2017 by Jordan123

[Jordan123]

Here an other break made there is one year, again not spherical.

[Sulphurstan]

Not THAT bad, come on!

[Wiley]

Just recall that cylinders break into a sort of wheel shape, not a sphere.

[drtoivowillmann]

Nonsense!

Only a question of a good primer, preferencially built up in three layers: the hottest nearby the colour composition, the coldest (almost pure black powder) outside, and a good and a not too fast flash for the breaking,

 

Yours truly: Toivo

[Jordan123]

Hi everybody, i come back for the news

Since few (too much) month i don't have time to pratical my best hobbie, but actually I have try the monoccapa prime : THAT IS GREAT

 

I have use a old batch of stars which are primed but not work really well, so i have remove a part of the prime in order to try monocappa on this stars, and i have shot a 3" shell tody all stars was ignite i'm really satisfaying

 

I recommended this prime, that ignite all of my stars and so i have a beautifull symetrical shell when she explod !

I wonder why we don't use only this "monoccapa prime" because she is the best i thought.

 

_______

 

I write on my note your process Toivo, this is a good idea to use 3 layers even if that took many times

[JOPETES]

Hola Jordan. Para romper conchas aereas mi consejo es que utilices de forma general cáscaras de arroz o similar envueltas en pólvora negra muy rápida elaborada en molino de bolas siempre con carbón muy ligero tipo sauce, balsa, álamo etc.., la misma pólvora que la de elevación de conchas aereas, de esta forma aseguras que el fuego se propaga o distribuye con mucha rapidez y uniforme hacia todas las estrellas y así lograr un buen encendido de las mismas. Por otra parte, es imprescindible una o dos capas de cebado en las estrellas que sea eficaz a altas velocidades.

 

Para romper conchas aereas con pocas capas de papel no recomiendo utilizar nunca KP (kclo4, azufre,carbón) porque es una pólvora de combustión lenta pero a la vez violenta debido al elevado valor de los gases producido por el kclo4. He visto fallar conchas aereas con KP a pesar de que las estrellas tienen buenas capas de cebado.

[burningRNX]

And a fast Google translation:

 

Hello Jordan. To break air shells my advice is that you use in a general way rice husks or similar wrapped in very fast black powder made in a ball mill always with very light charcoal like willow, raft, poplar, etc., the same gunpowder as the lifting of air shells, in this way you ensure that the fire spreads or distributes very quickly and uniformly to all the stars and thus achieve a good ignition of them. On the other hand, it is essential one or two layers of priming in the stars that is effective at high speeds.



To break air shells with few layers of paper, I do not recommend ever using KP (kclo4, sulfur, coal) because it is a slow-burning but at the same time violent powder due to the high value of the gases produced by the kclo4. I have seen aerial shells fail with KP even though the stars have good priming layers.

 

[aliksr]

Hi everybody !

 

Today i'm asking about the ignite of the stars this is for me the most complicated step for made firework.

So, i would know your view about this :

 

A shell who is wrapped better, stronger than an other one is she ignite most correctly ?

 

 

I thought than when the time fuse fire on the indoor of the shell the rice hulls coated with bp (or other stuff) ignite better the stars and other pyrotechnics stuff when the break is most diffcult.

In fact, a quickly break would have no time to fire all pyrotechnics stuff.

This thinking is because i use some good method of priming my stars and sometimes stars as not all ignite.

kindly confirm which powder you are using inside the shell to ignition the stars