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Questions about a star formula


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Posted

Im wanting to try out this blue formula, can anyone help me out with what i need to wet it with? water or acetone? And do these need to be primed if so what do you recommend. Thank yall!! Formula as follows: Potassium Perchlorate:61

copper carbonate: 12

Parlon:13

Red Gum:9

Dextrin: 5

Posted

The presence of dextrin says emphatically that the formula was intended to be dampened with water.

 

Water, or water with a little alcohol added to cut surface tension and improve 'wetting' is the most-common pyro solvent.

 

LLoyd

Posted

ok. thank you Mr. LLoyd. do you think they need to be primed?

Posted

Yep. Prime everything but black powder formulae -- just automatically. You won't regret having done so.

 

Especially with comps that are intended to burn coolly (blues, purples, aquas), you may exceed their critical wind velocity immediately after burst of the shell. If there's not something on there to carry them through deceleration, they may light in the shell, then be extinguished before the break spreads.

 

Primes offer more than one function -- they're not JUST to help ignite the stars, but often to sustain the burning during deceleration. They also can serve as an isolation layer between friction-sensitive stars, and to present a 'dark relay', so stars can appear later in the break expansion.

 

Just get in the habit of priming everything but BP formulae.

 

Lloyd

Posted

good information. Thank you. One more question haha. what would be a good prime for this time of star?

Posted (edited)

Since that formula contains no carbon or sulfur, it might be a little 'touchy' to ignite, and even though it contains perchlorate as the oxidizer, will likely have a low critical wind velocity.

 

Therefore, a fairly hot, but slow-burning prime would be appropriate. One containing a good deal of carbon, and coarse, UN-milled ingredients will likely be the best. In general, you want primes to be of fairly coarse materials, so that they will both burn a bit more slowly, and so they'll leave molten droplets of combustion products on the surface of the star.

 

Also, 'hot' primes should be topped-off with a thin layer of rough-mix BP prime, in order to ensure THEIR ignition! <G>

 

75-15-10+5 of perchlorate, charcoal, red gum, and +5 dextrin is a good medium-hot prime. Don't mill the ingredients, so long as they are 200-mesh or smaller.

71-18-11+5 of KNO3, charcoal, sulfur, and +5 dextrin is a good rough BP prime. Again, no milling unless you're starting with coarse ingredients.

 

The best way to prime almost anything is to "step-prime". In that case, you can use only the BP rough-mix, and dispense with the hot prime -- the color comp in the step-mixes will make it hot enough to transfer fire to the star well.

 

LLoyd

Edited by lloyd
Posted

Thank you so much for that information Mr. lloyd.

Posted

The step prime is also the most convenient when working small scale. Rather than stocking several primes (or mix up small batches for each time) you just keep a bit of the star comp and mix with BP.

Posted

I would also caution you not to be tempted to use a little of that BP mill dust you have "just lying around". It's too fast, and burns too cleanly to be an effective prime.

 

Often, folks who use mill dust (or deliberately mill their primes) will find that the prime just "flashes" off the surface of the star without igniting it.

 

Lloyd

Posted

Lloyd, I follow completely your explanation about molten droplets staying on the star and thereby improving ignition. However I'm wondering, will a faster/hotter burning bp with step prime not result in better star ignition? What I found in for instance Jopetes files is that a hot, fast charcoal is required to make sure the prime stays lit during high velocity trajectories.

 

But even with step prime on some willow or glitter stars, I'm still able of blowing loads of stars blind. My prime however is always milled, not as fast as lift meal would require, but still quite fast meal. Might this be the issue for my stars not igniting? The layer is at least 1 mm thick, verified by cutting the star and measuring the layer.

 

Sometimes I do get perfect ignition on some stars, even high % aluminium white streamers or peony color star breaks, but simple willow or glitter can and will blow blind. I'm quite in the dark here, and am quite willing to support your theory regarding the milled 'too' fast star prime meal. Since most of the time there are different batches I use to prime my stars. And some might be rougher then others, or applied with less water at the final priming stage then the other ones.

 

Furthermore regarding this issue, the stars are rock hard, cause I can hear them fall down like little rocks after the break. Any input here would be much appreciated ;).

 

I tried (I believe your) Pinball prime, topped off with bp too. However, nothing has given me the 'ultimate' ignition key so far. Almost all of my stars are round.

Posted

A fast BP prime can actually work against you.

 

First -- it insulates the star material from the heat of the burst charge; so any ignition during the explosion will be ONLY to the prime layer.

Second -- it burns off so quickly that the stars are immediately exposed to cool outside air at too-high velocities to remain lit.

 

Don't mistake the speed of burning of 200-mesh rough powder. It's fast enough, just not AS fast as mill dust.

 

If plain willow and glitters are blowing blind (even without any prime), then I suspect either you're breaking the shells WAY too hard, or you're trying to break them only with a flash bag, and without black powder filler (polverone or grained powder) among the stars.

 

Only extremely fast-burning stars will survive a 'pure flash' burst. With a BP filler, the amount and force of the flash powder may be greatly reduced. It's purpose then is simply to get all the filler involved before the shell opens. The filler commutes its combustion heat to the stars, and also forms a fairly large globe of hot gasses through which the stars must travel before reaching cool air. This aids in igniting them.

 

LLoyd

Posted

WOW. SOUNDS LIKE U KNOW A THING OR TWO ABOUT FIREWORKS. IM JUST GONNA COPY DOWN UR FORMULAS FROM EALIER AND DO AS U SAY

Posted (edited)

Chunn,

I'm no 'fireworks genius'. I know many folks who are better pyro chemists than am I, and many, many better shell builders. But I've built aerial fireworks since 1965-66, and worked professionally in it since 1995. I even got lucky, and got in ten years as the GM of a well-known close proximity fireworks manufacturer before I officially retired. Now I design processes and make production machinery for fireworks manufacturers and military pyro contractors.

 

Edison said -- "Genius is one per cent inspiration, ninety-nine per cent perspiration".

 

I won't spout too much theory, but I can tell you what works for me, and why.

 

Lloyd

Edited by lloyd
Posted

That is amazing. Ever since i was small my dad would beat my butt for getting in to his shotgun shells and taking all the power out of them. i have just alwaz had a passion for fireworks. every christmas and bithday all i wanted was fireworks. well now im married with 5 kids and cant afford the commercial fireworks haha i decided to learn how they are made. only thing is i would hate to get in trouble for making innocent fireworks for my family on the holidays so im gonna seek towards my licence. My only worries is i live in a subdivision, they arnt gonna approve me making fireworks here. so ill just have to figure out my options. sorry bout all the bad spelling. There is just so much i dont know. Can canister shells be as good as ball shells? ive just heard its hard to get a good break pattern with them, not sure how true that is

Posted

Can canister shells be as good as ball shells? ive just heard its hard to get a good break pattern with them, not sure how true that is

----------

Good as? Oh, Every BIT as good. But different. You won't get the same spherical burst from a canister as from a ball shell, but then, that's not the effect you're looking for!

 

Lloyd

Posted

That is true. i will say this though. i know u might laugh at me considering the shells ur used to but those darn excaliber shells are pretty darn spherical and loud. dont know how those chineese people do the things they do. i tolk one apart one time and it seems the stars and power were just thrown in there but yet they break so darn good haha

Posted

and they do all that from a 1-1/2" tube. Beats the heck outa me

Posted

Most of the shells we made at the close-prox factory were sub-2". They all broke roughly spherically... but that's because they were approximately 'square' -- that is, their height was close to their diameter.

 

If you break a 'square' cylinder shell hard, the burst will be roughly spherical. Long cylinders with rings of effects give a different look; but they're supposed to do that.

 

Lloyd

Posted

Usually canister shells fill the sky with effect, ball shells tend to make better spherical bursts in the sky.

Posted

oooo gotcha. i really appreciate all the help. i like making canister shells better i just got discouraged that they wouldnt be big and spherical. Ball shells for me are a pain cause i dont have a star roller or anything im haveing to cut all my stars and trying to get them to stack in a ball shell drives me crazy. haha. think im gonna go back to canister shells.

Posted

Arthur,

Both ball shells and canister shells "fill the sky with effects". We made 1.75" ball shells, 2.5" ball shells, and canisters ranging from 2" down to 1-3/16" o.d.

 

Every one had an unique effect, but ball shells and square canisters of the same size give roughly the same burst pattern (if broken right), with the canister appearing just a little more 'full', but not quite as round.

 

Lloyd

Posted

Mr. Lloyd which one do u prefer?

Posted

Chunn,

Each has its best venues and purposes. I like the look of a perfectly-broken ball shell very much. They look great in singles or volleys of three to five in angles.

 

But I also like the look of a barrage of small canisters fired to build a "curtain" of stars. And if you want to do an effect like "horse tail" shells, the canisters have it, hands-down.

 

I don't prefer one over the other. Canisters are easier to build in those small sizes. I guess that would be a plus on their side.

 

LLoyd

Posted

Gonna have to look up horse tail effect. Im gonna give canister shells a try, see how i like it.

Posted

i would have to say my favorite effect is the spider web. even though i havent been able to make one.

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