Crackling stars w/o Chlorate (NOT Dragon Eggs!)

[Ubehage]

Hey there guys and girls!

 

Tonight, I stumbled upon a recipe for DE w/o perchlorate.

Obviously, I had to try it. Worst case, nothing would happen. Best case, I have solved a problem

 

Well, to start off:

This is not a recipe for Dragon Eggs.

These cracklers will explode instantly upon ignition. However, only the ignited part will explode. The remaining star will be untouched.

So, a prime is needed.

 

75 Bismuth Trioxide

15 Magnalium

10 Black Copper Oxide

Approx. 10% NC for binder.

(Some people suggest +5% atomized AL)

 

 

I haven't done much testing with this yet. I just made 3 small batches, to rule out the possibility of functioning DE, if I had screwed up the first batch.

 

I hope someone else will find this as useful as I did

[Stef727]

So you could make 1x1mm stars and use it for star cores? or granulate it to make something a bit bigger than sugar and mix it in TT and pump it?

 

You prob should do some burning tests of the lose powder because to me it sounds like it could explode.

Also what mesh is the Magnalium?

Edited March 15, 2015 by Stef727

[Ubehage]

My magnalium is 150mesh.

 

I made some 3mm star-cores, and are waiting for the prime to dry.

 

I did some burnrate tests of the loose powder.

It does crackle, with loud bangs, even as a loose powder.

It is quite difficult to ignite a whole pile. Once a few "molecules" are ignited, they explode and blow away all flame.

I'd call it impossible to light a pile with a normal lighter

 

I did manage to light a small pile at once.

Imagine a pound of thermite, filled with crackle. That's the visual and sound-experience you get from that.

Edited March 15, 2015 by Ubehage

[Stef727]

My magnalium is 150mesh.

 

I made some 3mm star-cores, and are waiting for the prime to dry.

 

I did some burnrate tests of the loose powder.

It does crackle, with loud bangs, even as a loose powder.

It is quite difficult to ignite a whole pile. Once a few "molecules" are ignited, they explode and blow away all flame.

I'd call it impossible to light a pile with a normal lighter

 

I did manage to light a small pile at once.

Imagine a pound of thermite, filled with crackle. That's the visual and sound-experience you get from that.

I was asking about the powder burning tests because I was kinda scared that it could ''self contain'' and explode like FP does, and didnt want 100g to blow in my face.

 

Also could the crackle star be placed in a specific way to maybe split a star? kinda like a crosset?

Edited March 15, 2015 by Stef727

[Ubehage]

I was asking about the powder burning tests because I was kinda scared that it could ''self contain'' and explode like FP does, and didnt want 100g to blow in my face.

 

Also could the crackle star be placed in a specific way to maybe split a star? kinda like a crosset?

It was one of the first things I tested: How aggressive it was burning, and if it was able to contain the combustion like normal DE.

I propably should have said so in the description.

 

That's an interesting question. My first thought is, that it will propably blow out the star.

I'm not in possession of a star-roller yet, so I don't think I will perform that test in a while...

[Ubehage]

I have just finished some further tests and "playing" with these stars, and I made a little discovery, which I feel I need to share with anyone else who might attempt what I did:

 

I made a small fountain, in a 8mm x 100mm tube, using only these stars. Just for the fun of it

I snuck a fuse down the tube, and loosely filled it with stars.

I stamped the tube on the table, to compact it more. But no ramming or pushing, or anything.

 

For the first few seconds, it was as I expected. But then it exploded!

 

And my warning here is: I have NEVER seen a real-life explosion as powerful as this one!!

Don't do what I did.

[Arthur]

I've seen some crackle stars (about 10mm cylinder stars) that had orange flecks on the side of what looked like a pressed BP based star. They work well and crackle well as the star body exposes then heats more of the little flecks. You could put about 10% crackle formula into a simple prime/BP base with dextrin and let them dry

 

Copper oxide thermites can go high order -which is what it appears yours did.

[Maserface]

Did I miss something? Do dragon eggs usually have perchlorate?

[Mumbles]

I was thinking the same thing Maser. I'm also curious how this is not a recipe for dragon eggs. Or for that matter why they'd think that filling a tube with them would not result in a large salute.

[FlaMtnBkr]

That is a standard Dragon egg formula. I'm really curious what formula you usually use for "Dragon eggs"? The only formula for DE that I know of that contains perchlorate is USApyro's that uses a different binder than NC. Since they don't have the NC it needs a little oxidizer to help with the smolder phase.

 

I like the 37.5, 37.5, 25 bismuth, copper oxide, MgAl better. It uses half the amount of expensive bismuth and work well for me and are loud. These formula also rely on the NC in the binder to work correctly. I use 10% NCL and add enough to make soupy and let evaporate until it can be worked with. If you don't add the extra they don't work as well and sometimes stop working over time if they do work at first. Maybe because of moisture intrusion or maybe because of nitrate. Some people used to think nitrate from prime killed the effect over time. But I've never had the problem though with the extra NC.

 

If you have any questions I have experimented a lot with DE. Plus there are many threads on them with these formulas if you look around.

[Ubehage]

It seems like I have been wrong about my definition of Dragon Eggs.

I have always seen them as stars that, upon ignition will smoulder for a little while, before exploding.

 

That is why I expressed these as not being DE. Because these ones explode instantly, and it seems to be a little difficult to get a whole star to explode as one.

[FlaMtnBkr]

They aren't really stars but more like granules or microstars. And they can have a delay. The ones that pop as a whole have a bit of a delay as the entire granule gets going and gets up to heat. But it's only about a second. If the MgAl is too fine little pieces pop off as they get hot and this happens faster with virtually no delay and creates a crackling sound instead of one loud pop. Edited March 18, 2015 by FlaMtnBkr

[Ubehage]

If the MgAl is too fine little pieces pop off as they get hot and this happens faster with virtually no delay and creates a crackling sound instead of one loud pop.

Thank you very much for that explanation

[FlaMtnBkr]

I have experimented with DE a lot and can tune them pretty well using different methods. It sounds like your MgAl is a bit too fine so that one granule makes a bunch of little popping or crackling sound.

 

You might try that formula that I listed above as I didn't have the best of luck with the one your using. I have good luck using my 200 mesh MgAl. I think you might have said you are using more coarse metal which might point towards that formula. Or it might just be the inaccuracy in grading and what part of the drum our materials came from.

 

If you would like some pointers feel free to ask. When an 1/8" cube goes off all at once and sounds like a .22 it is pretty impressive.

[Arthur]

IMO Dragons Eggs are simply high order bangs from a heated copper thermite, the delay is usually caused by either the star body matrix or simply the mass of the tiny crackling piece. Almost certainly Dragons Eggs are bound with NC lacquer.

 

Every piece I've read about thermite cautions that a copper oxide thermite may go high order, IMO Dragons Eggs confirm that.

[Mumbles]

Dragon egg compositions are certainly quite brisant. They actually function more like a strobe composition. There is a smoulder phase, and a "flash" phase. Basically there is a dark reaction that builds up an intermediate (generally a reduced metallic oxide), and then a rapid bright reaction after it builds up to a critical mass when it all explodes. Just like a strobe, everything is tunable. The smoulder phase can be seconds to nearly instantaneous.

[karvannan]

now in china they discovered crackling without using bismuth or lead and it is water based but i donot know the formula they have ready mix chemicals to enhance the colors also

[FlaMtnBkr]

We need a formula! And what do you mean by enhance the colors? A separate effect?

[MrB]

Colored crackle. Where the sparks have a distinct color. I've seen red and green, but have no idea what goes in to making them. They cost 4x as much as the regular green plastic balls with standard crackle in, so i'm guessing it has a slightly higher cost to it, when in production. Also, people who had some, claim they weren't as loud as the regular stuff.

 

At least i think thats is what he's talking about.

B!

Edited April 1, 2015 by MrB

[dave321]

now in china they discovered crackling without using bismuth or lead and it is water based but i donot know the formula they have ready mix chemicals to enhance the colors also

 

we need more details of this for our databases

[FlaMtnBkr]

With the type of guys that like pyro someone has to work in a lab with some sophisticated equipment that can determine what they are using.

 

In fact my dad has a friend that has hundreds of drug patents that works at the local university. He has the equipment but is a bit paranoid using it for stuff that is not work related even though it's his lab purchased with grant money he worked for. I will have to see if I can talk him into it as he does have a good pyro streak in him.

 

Just have to get my hands on the newest crackle. Especially colored stuff as I haven't seen that yet.

[MrB]

Just have to get my hands on the newest crackle. Especially colored stuff as I haven't seen that yet.

 

We had red and green a year ago, but not this last new year. Not sure if it was due to restrictions of the content, or if it's a sales thing.

B!