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Posted (edited)
What about technology.... NC? small cut? Edited by Karlos
Posted (edited)

Yes, I used home made NC (acetone and Ping Pong balls (table tennis)) ..

 

I'm just pushed composition during 10 mesh net.

understand ? :)

I primed stars with greenmix + 4% Al flake (600mesh)

 

in real, eggs explodes wery loud.

 

Sorry my english is not wery well, if you have any questions, ask, i'll try to answer.

Edited by lokys
Posted

What about another binder than NC? Maybe, small cut stars 3 mm will work better. Acetone evaporate from composition wery guick, and composition is brittle.

I tryed 5% of resin and alcohol and composition crackled too. Maybe red gum can be good binder too.....or not?

Posted

I don`t know, i just tryed NC.. In tutorial ,which I used, was written that like binder need NC..

i haven`t try any others binders.. and red gum is more expensive than NC ..

 

I never had tryed ,, cut stars technology'' . maybe it would be better.. but for me enough my technology :)

Posted

Karlos, they shouldn crack when acetone evaporates. I never tried them, but if so, then try higher consentration of NC paste. And I believe there is no need to make DE big such as 3 mm cut, since they crack very loudly if even if they're small so I dont know if it is nessesery to make them big.

 

PyroMan ^_^

Posted
Pyroman: maybe yes. I hawe been interested(not lot ago) in rain willow from China. I thought, that stras are made from special composition. Just I know, that contain crackling granules, because i seen many videos and special one, with green crackling palm. Really, this is black powder formula with crackling microstars, but I dont know how(size) od granules and percentage in stars. Perfect 6' shell pyroman!
nice crackles.
Posted

Hey, thanks ;) Yes - those are some nice crackling stars, when I get my Pb3O4, I will try them in diffrent combinations. Then, I will be able to say sth about them... Good luck!

 

PyroMan ^_^

Posted
Which formula did you use?
Posted
Maybe, small cut stars 3 mm will work better.

 

For Dragon's Eggs, smaller is better. The whole particle rarely explodes if you make it larger, though sometimes I have gotten a multiple pop from a single larger particle.

Posted
Which formula did you use?

 

 

 

Pb3O4.............................................81.8

Mgal 200mesh                 ...................9.1

CuO               ...................................9.1

  • 3 weeks later...
Posted

I'm kinda' short on Mg right now, so I'm wondering if maybe I could get by with Al. The closest I've seen in any literature is Magnalium, and I've gotten that to work just fine, but nothing was said about just Aluminum. They didn't say you couldn't, they were just silent on the subject. Also, I've only used Bi2O3. I've already been exposed to enough heavy metals in my lifetime.

 

The only Al I have right now is about 5 micron dark stuff. The MgAl I was using was about 160-200 mesh, IIRC. I seem to recall something about particle size being a critical factor. I know that the actual size of the microstars is best kept around one to two mm, and I think I have a pretty solid theory about why. If the stars are too big, you're just wasting comp, because one zone of the mass will heat up faster than another, and only the portions which have reached that critical temperature will actually react. The rest just goes flying off.

 

If a way to heat a large quantity of the comp isothermally could be found, it would be interesting to try, just to see if a correspondingly bigger reaction would result. I think slow heating to the critical temp would probably be a little more controllable, as well as a little more measurable. Just dumping BTUs into it probably won't tell too much. Flash or thermite definitely have the caloric value, but would be like killing a roach with a grenade in an application like this. Some kind of heated pressure vessel with some really fine thermal control.

 

Just a couple of thoughts.

Posted

Stars upwards of 1/4" can be made of dragon egg composition if you take care in selecting formula, mixing, and priming. You are right about the MgAl particle size, it plays a critical role. With the MgAl you have 1-2mm is the max, but with 60 mesh MgAl, you can approach 1/4" like I said before. I like to think of it as the the reaction outruns the delay. With too large of stars, you will get a sizzling, as the broken off pieces complete the reaction.

 

I don't know if straight Al or Mg will work. I have heard that 70/30 Al/Mg is ideal for this composition. Others (mike swisher), have stated that the alloy is required for the reaction. Mg smoulders with the oxide, and the Al gives the thermitic explosive reaction. This raises several questions in my mind, but I will accept it for the time being. Namely, why would the more reactive metal only smoulder, as the less reactive metal reacts explosively. Even if it is the Al providing the smoulder, why would the less reactive metal react first?

 

I proposed a question to him about intermediate oxidation states. All of the common materials, Pb3O4, Bi2O3, and CuO, have intermediate quasi-stable oxidation states between the oxide and free metal. Mr. Swisher claimed, a successful reaction was possible with litharge, the intermediate state I had in mind. Given this fact, it should in theory be possible to make eggs from only a pure metal.

  • 2 months later...
Posted

Yafmot, there is a thread on here about making your own magnalium by melting scrap alu and mag. Once you have yielded the ingot from your melt, it breaks up like glass and is fairly fast to mill in a ball mill. Just be sure to use a seperate container and milling media so as to not contaminate any of your other chems.

 

The pyroguide formula I used for making bismuth dragons eggs actually called for +5% alu powder and I can attest to how well that formula works, although I haven't tried any in a shell yet so I'm not sure of how well they will light. I was thinking about maybe using some silicon powder in my prime but need to research that some more.

 

As far as the size of these little jewels, I pressed mine thru a 14 mesh screen but the commercial ones I have in some crackling fuse were round, as if they were rolled. They are smaller than a BB but I was amazed at how consistant the size was and again, they were perfectly round. I'm sure they screened them for the size but I wonder what they used for a core to roll them. (thinking out loud)

Posted
I have and they didn't work for me. They just smouldered and popped, without a bang.
Posted
Which dragon egg composition did you use?
Posted
I tried two compositions, the one had only Pb3O4 and MgAl, the second had also copper oxide. They were binded with a dinitrocellulose in acetone solution.
Posted

Yesterday I made a batch of Pb3O4-Dragoneggs, and they are really loud! It is the composition which is listed at pyroguide.com (containing Kno3, CuO and S).

Does anybody know why dragon eggs explode so loudly? I can't imagine which chemical reaction leads to the loud cracks..

 

Would be nice to know!

Posted

It's fairly common knowledge that magnalium 50/50 is the alloy preferred for making dragon eggs. Just Al or just Mg won't work- you will get a white star.

 

AFA mesh size of the magnalium, I've made eggs w/the finest magnalium I have- something on the order of 600 'mesh'. Mostly, there are more, closer spaced reports and the eggs are somewhat easier (quicker) to ignite.

 

The comp I use is:

Red lead............70

Magnalium.........17.5

CuO black..........12.5

Bound w/NC lacquer.

 

I'm going to make a small batch w/Mg and Al mixed 50/50 w/o alloying- just the two elements mixed by screening- to see how well (or IF) it works. IIRC, I read somewhere that it would work, but I'm fixing to see for myself.

Posted
I used selfmade MgAl, I just put it in my blademill and ran it through a sieve ( I don't know the exact mesh size, but should be around 100-120 mesh). It works fine!
Posted

Dragon eggs made w/ Al and Mg as separate elements added together did not produce a usable effect. The ignition was the same as usual, but had only a small crackle effect. Burned bright, obviously- but not as a dragon egg.

 

The mesh was very fine, dark pyro-fine, actually. In the same mesh, magnalium worked, although the reports were closely spaced together as might be expected from a mesh size finer than 200.

Posted
The original effect was made using a different alloy than 50/50. There are some mixes that use a few parts of atomized Al IIRC, that some claim to be louder. I have been under the impression that MgAl alloy is critical to the effect, but it can somewhat be tuned by the addition of small amounts of pure Mg or Al.
Posted

In a conversation w/Lloyd S. @ recpyro, he indicated that using an excess of Mg would cause an increase in frequency.

 

His thoughts were, there's more Mg "presented" at the surface of smaller mesh magnalium, and Mg is what's consumed during the smoulder phase, so "having too much of it (Mg) present results in a very rapid smoulder that spawns multiple little cracks that sound like an errant electric arc."

 

That "electric arc" is what I've been trying to recreate, I made it accidentally only once. I just got some Mg to use for this, but I havent tried adding a small percentage to the standard dragon egg comp to see what the results will be.

 

Lloyd had the same 'problem' w/a batch as I was trying to make on purpose. His problem turned out to be a batch of magnalium that was 65/35 Mg/Al instead of 50/50.

  • 3 weeks later...
Posted

hello!

 

 

This is my home made dragon egg`s

 

 

 

 

And here is my star mine D1 Glitter to D.Eggs :

 

http://www.youtube.c...u/1/MlCancj-fvA

 

Very nice! Was the D1 rolled on dragon rgg centers? Can anyone tell me if it's safe ro pump stars or gerbs w/ DE? Any special considerations or precautions?

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