13 replies to this topic

[sevin]

A friend gave me some 7/8" plastic shells that he ordered because he said that he didn't need them. They're SO TINY! What good are they? I don't think I could fit more than 1 star in it!

[Dan]

u could always make extreamly small stars (1/8") that have a long burn time.
u could then attach them to the end of a rocket.

[Loci]

you could fill them with Dragons Eggs? or use them for salutes perhaps?

[Richard H]

I'd fill them with dragons eggs and a pinch of flash or whistle burst, and then use them in candles, mines, small shells etc.

[sevin]

I'd fill them with dragons eggs and a pinch of flash or whistle burst, and then use them in candles, mines, small shells etc.

I'm kinda new to pyrotechnics...could you explain what a dragon egg is and what it does? Thanks for all the responses!

[Richard H]

A dragons egg is responsible for the crackle effect in fireworks. A formula, such as the one below taken from the Best of AFN III, is used:

Bismuth Trioxide 81.8
Magnalium, granular, -100 mesh 9.1
Copper(II) Oxide, black 9.1

When this composition is prepared into very small granules of around 1mm in size, they explode with a sharp crack upon ignition. When many are used together the result is a loud crackling effect. These dragons eggs might be used as they are, or they may be used as a star 'core'. This is where a star is slowly rolled by adding a composition with a suitable solvent, onto the dragons eggs. The end result is a star which produces a loud crack before it burns out.

[sevin]

Wow that's awesome! Thanks! I'll try that.

I noticed Bismuth Trioxide is quite expensive from SL, they mentioned it's a safe alternative to Lead Tetraoxide, which is about half as much. What are the trade offs of using one or the other?

[Richard H]

I'll let you decide

Lead Tetraoxide (MSDS)

Bismuth Trioxide (MSDS)

In summary lead tetraoxide is a more dangerous chemical to work with, as it is a chronic poison.

[Phoenix]

And after it's done its crackling, it's gonna come down somewhere

A pound of bisthmuth trioxide will last a long time, or you could use bismuth subcarbonate (cheaper), though I've looked and can't find any formulas that use it.

[Loci]

A pound of bisthmuth trioxide will last a long time, or you could use bismuth subcarbonate (cheaper), though I've looked and can't find any formulas that use it.

This is true, or you could use Bismuth Subnitrate in the following formula :

Bismuth Subnitrate 70
Magnalium, granular, -60 mesh 20
Copper(II) Oxide, black 10

However, the Bismuth Subnitrate cost my 10 quid for 100grams! so Im not sure if this is cheeper than what you had in mind!

[Dan]

dont forget to where a good quality resperator (not the white ones made for sanding, the ones that r like $30 and look sort of like a gas mask) and also besure to where gloves too!!! and also safety glasses if ur resperator is only a half face (meaning it doesnt cover ur eyes)!!

[paul]

I made them with lead tetraoxide with good success. Work clean and safe with a dusk mask and gloves and you?re fine. Lead tetraoxide is only dangerous, if you inhale it or when it gets into a mucosa (don?t know how to use this word with the right syntax ): )... It is quite insoluble in water and so it is "not as dangerous" as other chemicals..... But its cumulative!!! After work wash your hands and your face with enough water.

By the way: With bismuth trioxide we had more success. Sometimes its better to go the more expensive way and buy the more expensive but more harmless stuff.

Edited by paul, 04 August 2004 - 03:22 PM.

[sevin]

Thanks guys, that's kinda what I figured. And yes, I have invested in a cheap respirator. I think I'll try both, and see which produces favorable results. Awesome forum btw!

[dfk]

By the way: With bismuth trioxide we had more success. Sometimes its better to go the more expensive way and buy the more expensive but more harmless stuff.

In what ways was bismuth more successful you?