33 replies to this topic

[THEONE]

Does anyone know what is the burst charge of a stutata made by italians ?

[Carbon796]

They are essentially flash broken/boosted. Generally your advised to start at 50/50 Kp/AL. Then tune them up from there, based on testing.

Italteen3 / Anthony ( iirc ) as visited Italian manufacturers/builders in person. And has written some excellent tutorials on them. I would track them down, if your really interested. They're somewhat similar to a traditional spider insert. For a 9 timed spider shell. Except pumped stars are stacked in "sailor courses" 6 to a ring. And the flash bag is sized to completely fill the inner cavity. The spiking is laid between the columns of stars. And the cases are completely hand rolled-no end disks. Generally dry wrapped.

Of course your star priming and formulas need to be on par. For the increased wind velocities. As with most things pyro. It's not just one ingredient, or formula, or technique that makes a device function properly. But, a variety of components all working together.

Edited by Carbon796, 11 January 2023 - 02:08 AM.

[THEONE]

Yea i have seen some videos and i am aware of the way they made. The only info i am missing is the burst charge. I was thinking to expirament by myself till i found the correct ratios but before that i was wondering if anyone got the info. I was thinking just to try various mixes of spanish booster and B. I made some with 50/50 booster and BP but they broke really hard. Stars was TT and they didnt even light up or they may beoke up due to hard break. Yes i am interested

[kingkama]

Usually the breaking charge if insert Is hotter and contains a mix of various alluminium and magnesium, the main charge Is a mix of bp on Rice hulls and kp/al on Rice hulls, more or less the proportion Is 1/10 kp/al 9/10 bp. I tried a flashbag in main charge but the Power of the charge Lit the insert at the breaking, May Be i used way too much hot mix... One of the thing One must calculate Is that kp absorb heat Better Is mix kp and chlorate in the insert and priming all the stars with hot prime.

Edited by kingkama, 12 January 2023 - 02:18 PM.

[Carbon796]

Sounds like your talking about ball shells. Cylinder shells and their inserts do not use coated rice hulls.

Granulated BP and polverone are what you should be using.

Edited by Carbon796, 12 January 2023 - 03:35 PM.

[Carbon796]

To the best of my knowledge italteen3 was sworn to secrecy on the exact formula. And, gives out the the above 50/50 recommended starting point. Supposedly the real formula is somewhat hotter. So even if you had the exact formula. You would still be having issues. If your already blowing stars blind, with a weaker version. Plus the materials/chems are not going to be identical to what the Italians are using. So your still left with having to test and tune. Your devices to work with your avaliable materials. For your specific needs/taste/preference.

If your blowing the stars blind with the 50/50 mix. You probably need to adjust your priming, use less booster, or tone the booster down more. It's all a balancing act, making your devices work, how you like.

Edited by Carbon796, 12 January 2023 - 03:53 PM.

[kingkama]

Sounds like your talking about ball shells. Cylinder shells and their inserts do not use coated rice hulls.

Granulated BP and polverone are what you should be using.

Not italian use this kind of media too, less weight less cost.

[Carbon796]

Being as rice hulls are not required for building cylinder shells. And are generally advised against using them.

Having to purchase them, is an additional cost. So, your not saving anything there.

Weight is a non-issue. Where heavier is usually more of a benefit, then a hindrance.

The issue is bulk and compressability.

Traditional american-itailian cylinder shells. Both dump filled and stacked comet. Are spec-ed to use commercial 2FA, for the bursting charge. Being as cylinder shells gain a significant amount of their strength. From the proper consolidation of their contents. The last thing you really want to use, is a component that is compressible.

Especially with multi break shells. If your 3rd color break, in a 3 break to bottom shot shell. Ruptures the case upon lift. Because it compressed on setback, from the two breaks above it. Your going to have a dangerous problem. Not to mention, all of your time, energy, and materials. You just wasted, on building that shell.

There's a finite amount of room in a cylinder shells canulle for the bursting charge. Far less than what is available, in a similar sized ball shell. ( where in some instances you actually need to reduce the amout of bursting charge. By using a carrier, like rice hulls or cotton seed, ect. And also flame propagation issues. Issues that most cylinder shells do not have ). Do you really want to waste that space, filling it with a non-flammable, non-energetic component ?

I always used commercial 2FA for my canulles. Even though it's more expensive and slower that than my screen granulated BP. Because it's denser. Denser equals more burst charge, more expanding flammable gaseous energy. That means, I probably need to use less booster ( to tune my shells to where I liked them ) which is probably cheaper and also safer.

So, what were the supposed benefits of using rice hulls, in cylinder shells again ?

Edited by Carbon796, 13 January 2023 - 01:12 PM.

[kingkama]

Working in a italian fireworks factory i know of what I'm saying, you're thinking like an American who builds in an Italian-American way, with little string and a lot of glue, you don't need all the Mass of bp that Fulcanelli suggest(yes i ready It) You need to make the right layers of paper and string, use card stock in the main box. Therefore the structure is much more resistant and self-supporting What you put in doesn't affect how the shell will behave on launch. Reducing the weight of the shells becomes important when you produce dozens of them, since the bp necessary for launching is expensive and cannot be produced but must be purchased by law. We often refer to the manufacture of a single Shell or a dozen a year, those who do it for work use construction standards that take cost and effectiveness into account. So what I said makes sense, maybe not to you mr carbon, cause your way Is different, Many also in Italy build using polverone and bp cannules, but for the most part they use supports covered in bp in the shells with inserts, with additives of various types to increase the temperature and quantity of gas, to widen the expansion radius of the Inserts.

[THEONE]

I was thinking to make a different burst charge for stutatas only. My idea is to add 20% of slow 5/3/2 flash to regular BP, ball mill and granulate it. It should be hotter than regular BP right ? I just wondering if it will be better to add the slow flash in powder form into a regular BP or add it into ungranulated BP and then granulate the whole mix. Your opinions.

[kingkama]

I was thinking to make a different burst charge for stutatas only. My idea is to add 20% of slow 5/3/2 flash to regular BP, ball mill and granulate it. It should be hotter than regular BP right ? I just wondering if it will be better to add the slow flash in powder form into a regular BP or add it into ungranulated BP and then granulate the whole mix. Your opinions.

you should never grind flash together with gunpowder, the aluminum will ignite and the ball mill will explode. The best solution is to make a flash bag by mixing gunpowder and Spanish booster in powder (the Italians call it "peparuolo") the quantities are to be tested, the flash bag should reach the fuse of the couunterbomb, Then, in the center of the inserts, this Will cause a powerfull and much simmetric breaking. Slow flash can be also subbed by a 50/50 metal per/chlorate, much powerfull less chemical/moisture interaction.

Edited by kingkama, 14 January 2023 - 11:17 AM.

[THEONE]

Well i am using ceramic balls into my ball mill for this reason. Are tou sure Al or mgal will ignite inside a ball mill ? Because i was thinking to ball mill my star composition and it also contain mgal

[a_bab]

Milling metals and oxidizer together is asking for big trouble. It is totally forbidden.

[THEONE]

So i guess i have to mill metals separately

[Carbon796]

You really need to buy some better books, join a better forum. Or join a local pyrotechnics club. Assuming there's one near you. Because some of those questions/ideas are pretty basic issues. That for someone that's been on here for over ten years. Should know better than, to a attempt or think is possible. I'm not trying to offend you. But it seems like that is the kind of stuff you should have easily figured out 7 or more years ago.

If you need or want milled Mg/AL. It's much easier and safer to buy it that way. When ballmilled it can become (iirc pyromorphic) it can spontaneously combust. When the mill jar is opened and exposed to fresh air/oxygen. Plus ceramic probably won't cut it as a milling media for it.

If you want an BP/SFB mix. Mill the BP, screen in the SFB, and granulate it. Milling them all as one, will not gain you anything.

[kingkama]

So i guess i have to mill metals separately

Better buy metal pre milled and sorted by mesh, in short you can mill bp like ingredients togheter, oxidizer by its own, if you have the need metals, but never, never, never metals and oxidizer or chlorate and perchlorate with anything, also because for the most milling Is usefull and mandatory only in bp making for other buy premilled or mill anything wich Is not bp like by itself. Remember you can do anything as you like but evaluate risks and benefit.

[kingkama]

You really need to buy some better books, join a better forum. Or join a local pyrotechnics club. Assuming there's one near you. Because some of those questions/ideas are pretty basic issues. That for someone that's been on here for over ten years. Should know better than, to a attempt or think is possible. I'm not trying to offend you. But it seems like that is the kind of stuff you should have easily figured out 7 or more years ago.

If you need or want milled Mg/AL. It's much easier and safer to buy it that way. When ballmilled it can become (iirc pyromorphic) it can spontaneously combust. When the mill jar is opened and exposed to fresh air/oxygen. Plus ceramic probably won't cut it as a milling media for it.

If you want an BP/SFB mix. Mill the BP, screen in the SFB, and granulate it. Milling them all as one, will not gain you anything.

Where Is the advantage of granulate a flash mix of nitrate base with water, adding It to a bp base? what you will do is ruin both the bp and the booster, not getting the result i.e. increase the combustion temperature, at this point adding just a little aluminum would get you similar results, a booster of Better effect would Be magnalium milled to 20 microns 50% kchlorate 50% sprinkled in bp cannule, used by chinese in all cake insert...i think you also have some book to read or some clubs to join.

Edited by kingkama, 14 January 2023 - 03:30 PM.

[Carbon796]

I did not say there is any advantage in that. That is what the OP is wanting to do.

You may want to brush up on your comprehension skills . . .

Edited by Carbon796, 14 January 2023 - 05:53 PM.

[kingkama]

I did not say there is any advantage in that. That is what the OP is wanting to do.

You may want to brush up on your comprehension skills . . .

I tink i understand more than you think, wich Is the advantage to Say to someone how to wrong Better? Or in the case Say to someone to granulate a moisture sensitive composition, potassium nitrate will destroy the alluminium in spanish booster if added in composition with wather/alcool, producig gas and rising the temperature to Dangerous level. So someone have to learn how to comunicate and May Be read a book of basic pyro knowlege.

[Carbon796]

No one is talking about Spanish booster except you. And the OP. Comprehension, work on it.

Potassium nitrate comps, also containing aluminum. Are not moisture sensitive. Glitters and "flitter comps frequently contain both. And, are commonly water bound. There is no issue with doing that. Unless your comp, ALSO contains components that can push the PH to being alkaline. Noobs continually love to "push and repeat" that imaginary issue. Forgetting or not knowing. That they don't know the entire background or circumstances that can potentially cause that.

" So someone have to learn how to comunicate and May Be read a book of basic pyro knowlege. "

That person is clearly you.

" Working in a italian fireworks factory i know of what I'm saying "

Most people who actually do. Don't have to try, and con others into believing that they do. And, maybe if you stayed on point. And quit trying to pretend. I've said or suggested something. That I have clearly not. Your reputation and experience level, wouldn't seem to be so poor.