Microstars - which formula preferred with strong burst?

[boule]

Hi guys and gals,

I don't know if any of you still remember a certain consumer fireworks cake: Effect an immensly loud burst and a sphere of microstars with pretty much no hangtime, alternating between red and green.

One example

 

Well, I wanted to replicate the effect but unfortunately did not meet with much success. Making microstars according to the "mouse turd" method published by Danny Creagan is not really rocket science (http://www.wichitabuggywhip.com/fireworks/mouseturds.html) but getting them to light is another issue.

So far, I have been using rubber stars coated with greenmix +3% bright AL as well as a red kp lance comp + same prime and for experimental purposes putting them in a small 1" cup. They light fine with just BP as a burst charge but breaking them any harder to somewhat approach the effect of the commercial cake just ends up in a smallish salute and a lot of blind blown stars. There are some colored dots left when using whistle mix as a burst charge, when breaking with flash, complete obliteration of the effect results.

 

Now, either I need to work on my prime or find a comp that lights easier. Suggestions?

[pyrojig]

Most likely the bursts have Ti in them and that is the sparks that your seeing . If it is a colored salute then it is most likely a Mag type.

Edited December 5, 2013 by pyrojig

[pyrokid]

The color salutes boule is talking about definitely have stars. I seem to recall one of the cakes being dissected and it was revealed that the stars were rice grains coated in star comp.

[Zumber]

You are having a problem with your prime.

your prime isnt going to survive agaist high wind resistance which obviously because of using strong burst.

you will need such a prime that stick on the top of star during functioning and it should withstand high wind resistance, also you should prime your star heavily insted of just dusting a prime on star.

prime your stars atleast 1mm thick with hot prime followed by bp finish on top.

BP+silicon works just fine.

[Zumber]

for making microstars moderately damp your star composition and rub it on 20 mesh screen then roll that stars by adding star composition and spraying solvent in star roller.

[boule]

You are having a problem with your prime.

.....

BP+silicon works just fine.

 

OK, we agree that it is a problem with my prime. unfortunately those are microstars so a thick layer of prime is somewhat out of the question, just as a step prime is somewhat impractical. Now the big question is: how is basicaly swapping out the Al for Si going to improve my ignition? I already have (barely milled) black powder with a little bit of AL mixed in on there.

[Zumber]

after burning prime composition and molten SiO2 will stick on top of your star also it will survive against strong wind resistance.

[dan999ification]

Silicon sticks!

I gave up on priming the really small ones, instead I use them in matrix stars. A mix of c6 and bp can survive high speeds staying lit. Once lit the eggs are dumped quite fast. Charcoal comps with over 25% charcoal and some metal will also survive the wind and transfer fire, depending on the % you will or won't see the tail.

What size bombettes do you intend to make?

Which comp are you using?

 

Dan.

Edited December 5, 2013 by dan999ification

[psyco_1322]

You should really try some Fence Post Prime. Primes are not something you want to burn super fast, or clean. You want something that burns dirty that leaves slag and molten components on the star surface. It helps to get the star ignited at higher velocities, and keep things lit and burning.

[MrW]

My 2 cents.... some times I use a glitter comp as a prime, works every time (D1 glitter) then rolled in BP to finish off.but depends on your desired outcome. I haven't used it on high Ali comps yet.

[boule]

What size bombettes do you intend to make?

Which comp are you using?

 

 

Those were the original rubber stars from the skylighter formula - basically kperc, magnalium, red gum bound with parlon and some SrSulfate for color.

Second formulation was a leftover Lancaster KP1 red lance Kperc, Sr carb, red gum bound with dextrin.

The whole effect is something for smaller size fireworks so I am thinking about 1" (which were used for the testing) or 2" shells depending on how dense the effect is and how much burst can be crammed into each.

 

 

You should really try some Fence Post Prime.

 

 

Primes are all about heat transfer and I honestly did not think I would need more than a little bit of BP to heat up that minuscule star. since there is nowhere for the heat to dissipate to. I'll try the fencepost approach once I find some DE. Thank you for your usefull suggestion.

[Mumbles]

Heat transfer is of course key, but you have to deal with some other factors here too. You have to ensure the prime lights and stays lit at the high velocity, as well as ensure that the heat is being transferred to the star and not lost to surroundings. Even then if you do manage to light the star, you have to ensure that the star doesn't blow out. Using very fine, intimately mixed ingredients, particularly using finer magnalium can help prevent that part at least. It's difficult to say what the chinese formulas use as far as components, but perchlorate based stars are more prone to blowing out. Perhaps try something chlorate or Ba/Sr Nitrate based.

[Hoppy]

In my opinion, CMC has worked great while testing heavy boosted shells, 7/3, H3, KP, etc.

 

CMC makes rock hard stars that do not blow blind. Maybe Mumbles or many others can prove me wrong if they bind some up with CMC but I haven't had problems. I do need to try rice hulls coated among a few more tests. Just my $.02 while learning from everyone else here and continuing to make similar effects such as in the vid OP posted.

Edited December 7, 2013 by Hoppy

[Mumbles]

Have you ever tested CMC in colored stars? Most of the CMC I've seen available is actually the sodium salt, which is something I prefer not to add to stars I want to be colors other than yellow.

[dan999ification]

I originally thought you meant crackling micro stars, sorry for rushing through the thread.

 

For colour bombettes or shells broken only with flash I'm using veline stars cut with acetone, I advise cutting the small stars, rolling the pattie to get better density than mouse turds and rolling the prime on the pattie.

The corners help with ignition and the cut star should burn longer.

Pinball prime with some extra mgal or some ti rolled onto the pattie gives you better contact than priming dry stars, dust the stars with prime and they are ready.

You could get fancy but this works well enough.

 

A very light dusting of pinball prime with some ti will light high charcoal streamers, they stay lit at high speed and can transfer enough heat to small cut stars.

Flash will ignite ti.. If ti is on your star you have a very high chance of it lighting.

 

Dan.

Edited December 8, 2013 by dan999ification