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Posted

 

Yes I think close to 100% ignition, it was only a 5/8" bombette so only about 80-100 stars.

 

I used a lead tetroxide based formula, I think it was:

 

lead tetroxide - 70

black copper oxide - 12.5

MgAl - 12.5

Al - 5

 

Bound with about 20 parts paint grade NC lacquer, rolled out into a thin sheet and pushed through a 12 mesh screen.

Nc Is not mandatory pvb or phenolic could do the trick

Posted (edited)

Pyrophury - where did you get your Lead Tetroxide? I haven't seen it through the normal pyro chem suppliers, but wanted to get some and try DEs with it. I've heard they are louder (which I get is subjective), so I curious. Thanks.

Charles

Edited by cmjlab
  • 1 year later...
Posted (edited)

Here's a recipe that works great an few hooks and secrets are here.

Composition are 70 lead tetr./12.5 CuO/17,5 Mg all/+ 5 atomized al 325 mesh works well . Russian grade sperical al АСД4 are best for me. I try two this and АСД4 is more beter.

or try finer al like 400mesh.

Magnalium i use finer homemade milled to lightgray consistency. More than less magnalium have impurities ,and for best result need to wash with distiled water.

Bind with 20g NC 10% saturation to 100g. crack mix. 1,5 mm roled sheet past trought 2mm mesh https://ibb.co/72YhZS7

Spark mix without prime layer

Kno3 48

S 12

C 12

Fenol formaldehide 12 ~ Red gum 14

AlMg 10

Dex 4

Si+ 7 Si heatup microstar and more are triggered synchronously, without iner prime layer

Ti + 20 ( 100~250 microns) or FeTi

Atention here Roll with 10~15% alcohol/water saturation, no more. (For some reason alcohol destroy crakling star and after dry not work properly) Prime with outer prime to ensure good ignition.

https://ibb.co/4msm5Rs rolled to 4mm and sorted trougt 4mm sorter fence +outer bp primem layer with mixed granulated bp 80mesh.

https://ibb.co/WcDrDRp

https://youtu.be/dZoGjgRW3o8?t=108

one more observation that for some unknow reasons firs day after dry stars not work synchronously. I after drying put them in a sealed container to store for a few days or longer, then stars works more beter.

Edited by skysparkler
  • 2 weeks later...
Posted
Is it your youtube channel?
  • 2 months later...
Posted
On 9/18/2023 at 12:24 PM, Zumber said:

Is it your youtube channel?

Yes it is my YT channel

Posted

Nice videos posted over there ...thank you....!!

Posted
On 6/12/2023 at 02:12, skysparkler said:

Vâng đó là kênh YT của tôi

Can you share with me the formula of the colors you are using?

  • 5 months later...
Posted (edited)

I'm a little obsessed with trying to replicate the commercial dragon flowers in Chinese Shells (or "crackling flowers" in Japanese shells.)  I've read and re-read so many posts and tried so many compositions/methods and I still haven't gotten there.  In my workshop I have five crackle comps that work great (my new favorite is High-CuO, low-Bi2O3) and at least six "spark mixes" and have tried different binders and solvents, and my best efforts still result in a loud bang with a bright flash and some glowing slag, but not the tight chrysanthemum clusters that  commercial shells achieve.  I've dissected the commercial shells and the stars are rolled to about 4-5mm.  They aren't bound with NCL. I've tried SkySparkler's method (above) but never get the results he shows in his video.  I realize that part of the problem is that the chemicals I have available are probably not perfectly consistent with what others have, even when the labels say the same thing.  

I'm on my forty-third batch and still looking for the magic one.  

I'm just venting.  My real question is about smolder phase delay, which appears to be my stumbling block.  The consistent advice I read is that larger Al or Mg/Al or Ti particles have a longer delay, but which layer gets the delay?  Some posts say the dragon egg delay has to be long enough to let the spark mix ("smolder") prime achieve a molten state and ignite the Ti particles, while others seem to indicate that the delay is built into the smolder prime and the dragon eggs don't need a significant delay.   

When I increase the particle size in the dragon eggs they start giving multiple cracks rather than the one big pop I need. They also blow blind more often.  Even when it pops the way I want, it still doesn't give the flower effect.  When I increase the particle size in the smolder comp (the "spark mix") it will either glow and then just go out leaving the D.E. un-ignited, or it will ignite the D.E. but limit the crackle, or (depending on the dragon egg composition) sometimes it pops fine but still doesn't give the flower effect.  In the latter instance, I have yet to achieve a significant delay from a smolder comp - if they pop at all they go from prime to pop very fast, no matter what particle size I use in the smolder comp.

Does anyone have ratio of spark mix delay to dragon egg delay that works?

 

Edited by Soloserly
Posted

I have a bit success with dragon flower but its not perfect round flowers rather it gives nice flowers.

I have tried two methods.

First is I have added 100 mesh ferrotitanium itself in dragon egg mixture and then formed microstars.

I have used red lead black cupric oxide and magnelium 200 mesh and formed microstars using NCL

Note-it gives flower effect but sound of stars reduces.

Second method is I have used same chemicals but instead of adding ferrotitanium in composition itself I have added it above micristars,

First I made microstars then dried microstars  for 24 hours then I have damped microstars using very thin NCL and sprayed 100 mesh Feti and shaked well Feti have sticked in  outer side of microstars.....then again I dried microstars for 24 hours then It is primed with streamer.

Note- crackling sound is good than previous one and flowers are nice too.

I havent tried feti in prime layer

For this technique you need such a prime which just burn as a smoulder phase( may be high sulphur) if it leaves charcoal spark that streamer will be useless.

  • 4 months later...
Posted (edited)
On 9/6/2022 at 11:59 AM, cmjlab said:

Pyrophury - where did you get your Lead Tetroxide? I haven't seen it through the normal pyro chem suppliers, but wanted to get some and try DEs with it. I've heard they are louder (which I get is subjective), so I curious. Thanks.

Charles

Not sure where they got theirs but I picked up a 500g jar of Hi-Media on Amazon on sale for $24 w/ free shipping  a month ago or so and they still have plenty of stock.  This will probably last me a decade since I only plan on using eggs as star cores after I get them the right size to pop loudly and once. 

They have Yellow Lead Oxide (Litharge, PbO) too. 
No lead dioxide (PbO2), but it that can be made from Lead acetate or lead tetraacetate.  Lead acetate is cheap from the same seller, $14.50/lb.  Here's the full synth through either route from Brauer 2nd Ed.

Lead (IV) Oxide (PbO2)

I. 
2 Pb(CH3COO)2 x (3 H2O) + Ca(OCl)2 + 4 NaOH 
    -> 2 PbO2 + CaCl2 + 4 CH3COONa + 2 H2O

A solution of 20 g. of Pb(CH3COO)2 • 3 H2O in 50 ml. of dis-
tilled water is prepared and mixed with a solution of 10 g. of
NaOH in 90 ml. of water.
Good agitation is required. At the same time, a hypochlorite
solution is prepared from 14 g. of technical grade Ca(OCl);,
(effective Cl content 70-80%) or from double this amount of tech-
nical grade bleaching powder. Either compound is dissolved in
200 ml. of distilled water. After filtering, 80 ml. of this solu-
tion is added slowly and with stirring to the alkaline Pb salt
solution. The mixture is then heated and boiled for a few minutes.
As soon as the brown precipitate of PbO2 settles out, a few
milliliters of the supernatant liquid are tested with a few drops
of hypochlorite solution for the completion of oxidation. If further
PbO2 precipitates, an additional 10 ml. of hypochlorite solution
is added. This procedure is repeated until no precipitate is ob-
served.
Workup:
The dark, fine crystals of PbO2 are washed 5 or 6 times with
water. 
Then the precipitate is stirred with 50 ml. of 3 N HNO3
in order to remove any Ca or Pb salts or Pb(OH)2 which might
have been formed. After washing several times with hot water,
the precipitate is transferred to a Buchner funnel, thoroughly 
washed again, suction-filtered, and dried in a vacuum desiccator 
over Phosphorous Pentoxide (P2O5).**
Even after a long time in the desiccator the product 
still contains small amounts of water which can be removed 
completely only by heating for 1.5 hours in a stream of O2 at 160°C. 
The PbO2 is then analytically pure; the yield is about 85%.

2) To prepare a particularly active compound for special oxidative
reactions (e.g., organic reactions), the following procedure is used:

50 g. of Pb(CH3COO)4 is carefully broken up and ground in a centri-
fuge tube with 460 ml. of water until all of the lead tetraacetate is
hydrolyzed to PbO2 . The suspension is then centrifuged for 10
minutes, and the sediment is stirred up again with 460 ml. of
water and centrifuged.*** 
This process is repeated four times.
The last supernatant should give a neutral reaction with litmus.
Finally the PbO2 is stirred with 50 ml. of water, suction-dried
and washed with an additional 50 ml. of water. When the pre-
cipitate on a fritted glass filter is just barely moist, it is washed
slowly four times with acetone, using 25 ml. each time, and there-
after four more times with absolute ether, again using 25-ml.
portions. The PbO2 acquires a bright, coffee-brown color at this
point. It is immediately dried in a vacuum desiccator. Yield:
23 g. (92% of theoretical).

Pb(CH3COO)4 + 2 H2O -> PbO2 + 4 CH3COOH

This one has the obvious advantage of being cheaper... or it would be if 
you can get your hands on the acetic anhydride needed to make the tetraacetate from the 
acetate or oxide.  Hi-media has tetraacetate on Amazon as well, but unlike the other lead
compounds it's $100 / 500g.   Probably has something to do with being able to turn it into the 
dioxide by adding water.  Stuff like that isn't very shelf-stable.  ;-)
You could make it but all of the published synths require acetic anhydride as a precursor to 
itself.  There's some way around that but it's complicated and you'd be better off just buying
a small amount to jumpstart the reaction cycle if there was any common need for it in fireworks, 
which there isn't.  :P


**Phosphorous pentoxide  Although it's possible to get this stuff, it won't be cheap from a regular lab 
supplier.  Somebody on etsy is selling 20g vacuum bags of cheap it but that implies that they 
opened the original bottle and it's probably degraded.  It's sorta indirectly used to 
synthesize various nasty things for chemical weapons but that isn't why anybody cares about 
selling it to the public.  Mainly it just kinda spontaneously catches fire for no reason if it 
hits water or anything organic, like wood, and doesn't have much shelf life so even the chem 
warehouses can't keep it around.  Back in the 60s when the book was written it more was commonly 
used to dry things and it was kept around in quantity by labs because organic reactions hadn't 
gotten as fancy as they are now.  Also keep in mind they're describing prep of analytical grade, 
which is about 6 purity levels above what pyrotechnics needs for most things.  Lots of the cleanup 
is probably skippable, I'd just make sure it tested Ph neutral with strips and stop rinsing there, 
definitely skipping the HNO3 washes that are probably more problems than they're worth.  


***Have fun finding a lab centrifuge that'll handle 500mL tubes outside of ebay these days,
I wouldn't want to be in the room with that sucker while it was spinning.  :-)


 

HANDBOOK OF PREPARATIVE INORGANIC CHEMISTRY, Brauer, 2nd Ed, Vol 1, 1963, Downloadable from archive.org

https://archive.org/download/Handbook_of_Preparative_Inorganic_Chemistry_1_2_Brauer/Handbook_of_Preparative_Inorganic_Chemistry_1__2_Brauer.pdf

Edited by PyroGnome
Posted (edited)

Oops double-posted.

Edited by PyroGnome
Posted
15 hours ago, PyroGnome said:

Not sure where they got theirs but I picked up a 500g jar of Hi-Media on Amazon on sale for $24 w/ free shipping  a month ago or so....

***cut****

HANDBOOK OF PREPARATIVE INORGANIC CHEMISTRY, Brauer, 2nd Ed, Vol 1, 1963, Downloadable from archive.org

https://archive.org/download/Handbook_of_Preparative_Inorganic_Chemistry_1_2_Brauer/Handbook_of_Preparative_Inorganic_Chemistry_1__2_Brauer.pdf

Appreciate the suggestion - I had no idea they sold chems on Amazon to be honest.  HiMedia certainly sells some unique chems t reasonable prices.

Also appreciate the link - I reference this hand book (and a couple others) frequently!  

Appreciate it.

Chuck

Posted

Yeah they kind of bury them from normal searches since they're specialized, but you can find better prices than through most of the major lab companies for stuff that's not too bizarre.   It's amazon so prices tend to jump all over as their weird randomized algorithm-based sales are inflicted on your account (right now the lead tetraoxide is quite a bit more than it was when I bought mine).  You can get some interesting metal powders of various meshes like copper, bronze, steel, and iron that don't tend to be carried by pyro supplies for use in cold-casting at reasonable prices as well.  Copper probably isn't worth screwing with unless someone has figured out how to passivate it properly

There are at least two companies that specialize in bulk solvents which can be cheaper than the hardware store and are almost certainly higher purity. 

There are some nice anti-static plastic disposable chemical weighing boats which I use for everything on there in packs of 500 at reasonable prices, along with various wooden or plastic scoops and lab gloves that meet various safety standards which you'll have to dig around for.   

I've been using Microflex Midknight gloves which are black nitrile doped with something to make them dissipate static charges very rapidly.  That's probably the top concern over chemical exposure with most pyrotechnic mixes and the wrong gloves will build up so much static you can make firefly aluminum jump around a tabletop just by moving your hand within 6".  Those don't make it move at all. Great for stuff like Cab-O-Sil and aluminum flake that love to try flying everywhere if you have a charge built up, even if they're not directly dangerous like Cab-O-Sil.  

Neoprene stands up to acetone longer but you won't find any gloves made of that which are actually rated for ketone exposure since the test involves pressure which means they can't weaken very much before permeation occurs...   The only types I can find that work long term are the more expensive butyl or butyl / Viton, PVA (for short periods), and LLDPE laminate, the latter being better.  Alphatec 02-100 (LLDPE laminate) work better than everything else they sell, are reasonably cheap if you look around, and have a >480 minute breakthrough time under immersion (the maximum time Ansell runs the tests, although the certification only requires >30 minutes against 6 chemicals from a list for the highest protection category) for acetone, toluene, ethyl acetate, concentrated nitric and sulfuric acids, and every other chemical you could name aside from chloroform or methylene chloride.  They "only" last about 4 hours in SOCl3 or concentrated ammonium hydroxide but those aren't going to show up in fireworks manufacture (I hope).   I just mention that here since dragon eggs tend to be bound with NC in acetone and hand-kneaded so the longer you don't have to worry about lead getting through the better if you're going the lead route.  If it weren't for the solvent I wouldn't worry much about any getting through your skin TBH, but some solvents are very good at getting things through.  Ethyl acetate is actually worse on most materials except PVA and LLDPE.  Here's a handy chart:  https://cdn.mscdirect.com/global/media/pdf/search/ansell/ansell-chemical-glove-resistance-guide.pdf

 

Every once in a while what appears to be the cleanout of old stuff from a university lab or company closing gets dumped, typically lots of extremely hazardous stuff (Osmium Tetraoxide appears regularly, and is maybe the only inorganic compound that scares me more than concentrated HF) which I think is being done under the "if we're selling it we're technically not throwing it away" method of dodging hazmat disposal which would be extremely expensive otherwise.

Posted

I just saw uspigment.com on another thread and noticed that they sell red lead for $20 a pound, so that might be the best option right now unless amazon gives you a sale on it. 

Posted
On 9/6/2022 at 5:59 PM, cmjlab said:

Pyrophury - where did you get your Lead Tetroxide? I haven't seen it through the normal pyro chem suppliers, but wanted to get some and try DEs with it. I've heard they are louder (which I get is subjective), so I curious. Thanks.

Charles

I find a source in Paint shop.

  • 2 weeks later...
Posted (edited)
On 11/23/2010 at 11:48 AM, Mumbles said:

I've also been thinking about the effect that NC grade has upon the product. There are many different nitration levels and viscosity grades available. I'd imagine most of us just use what is available, such as wood lacquer, RC aircraft nitrate dope, (*cringe*) ping pong balls, or smokeless powders. This is a subject I've never seen covered in much detail.

TL;DR - Smokeless powder is the only thing that will have any trinitrate.  Most things will be a mixture of regular colloidon and dinitrate (guncotton).  The trinitrate is also referred to as "high-nitrated" and "pyro-colloidon" it seems. 

Wikipedia claims that the dinitrate is typically used in lacquers, and the trinitrate is used in smokeless powders at various percentages (extrapolated from one of the cited sources which doesn't specifically say that).  The percentage of each in a given mix can be determined by first dissolving whatever will dissolve in alcohol or ether, then drying and weighing the portion that didn't dissolve.  The trinitrate won't dissolve in either of those but will dissolve in acetone.  The nitrate and dinitrate should dissolve easily. The percent in smokeless powders according to Urbański, Tadeusz. Chemistry and Technology of Explosives varies depending on the intended bore size of the guns they're to be used in but rifle is listed at 13.1-13.3%.  It's possible that powder for pistols is higher and there's probably stuff out there designed to be even hotter for the higher chamber pressure modern sniper rifle and competition type rounds like .338LM / 6.5 creedmoor.   At some point they probably just switch to double or triple base powder though. I'm not too informed about reloading. 

Ping pong balls, according to another page, are no longer made of the stuff because there was an issue with them spontaneously bursting into flame when hit too hard, so if you use those and you didn't buy ancient ones from ebay you're probably just dissolving a styrene-mixed polymer.

One of the aircraft nitrate dopes I found an SDS for lists 9.8% cellulose nitrate, dissolved in mostly toluene with acetone, methyl-ethyl ketone, ethyl acetate, n-butyl acetate, and isopropanol, but it was an older copy of the SDS.  When I found the mfg. website, they list nothing but solvents.  This seems obviously wrong unless they've found a non-hazardous nitrate to use in there. 

Another (expensive) source not listed is https://sds.opi.com/sd_-_OPI_Nail_Lacquer_ALL SHADES_(US).pdf  clear nail polish, which is apparently 10-25% NC with mostly fast evaporating ester solvents and isopropanol, along with a small amount of titanium dioxide that would need to be accounted for due to its effects as a catalyst in some mixtures. Maybe someone will get lucky and find a shelf full of bottles for a dime apiece at a dollar store closeout sale.

The only non-polymer-activated cellulose nitrate I found at home depot was made by some subsidiary of rustoleum and has a large mixture of solvents but nothing obviously incompatible aside from the whole dumping flammable liquids into oxidizer / strongly reducing metal mixtures issue.  :P    NC content was listed at ~10%.  Of their several lacquers, only the clear gloss was plain cellulose nitrate, the others all contained polymer mixes of some sort in addition to that.  This could be good or bad, I'd tend to stray away from anything like that given the mixtures NC is normally used for. 

FWCB has quarts of NC but the page doesn't say anything about percentage or solvents so who knows, someone would need to ask. 

The last possibility is to buy flash paper from a magic supply store, they usually sell bundles of large sheets that would probably make enough for a couple of small batches of dragon eggs if you're careful, but it's expensive from some places. 

Hope any of that helps somebody.  I did a lot of hunting so I wouldn't have to screw with storing a jug of nitric acid. I had a small ~100mL jar back in high school that the chem teacher ordered for me and you really couldn't tighten the lid enough to stop the fumes from getting to the surroundings (hence acid storage cabinets in chemistry labs).

 

Edited by PyroGnome
  • 4 weeks later...
Posted (edited)

I have made some Dragon eggs recently. Tested them along with some Ind. red stars in a star mine. Take a look.

Dragon eggs composition: 

Pb3O4 – 70%

CuO – 12.5%

Magnalium (200 mesh) – 17.5%

Pyro Aluminum or 999 – 5%

10% Nitrocellulose Lacquer

IMG_20231109_185028.jpg

IMG_20231109_183014.jpg

IMG_20231109_133156.jpg

Edited by msantosh1989
Posted

Very nice!

Posted
7 hours ago, msantosh1989 said:

I have made some Dragon eggs recently. Tested them along with some Ind. red stars in a star mine. Take a look.

Dragon eggs composition: 

Pb3O4 – 70%

CuO – 12.5%

Magnalium (200 mesh) – 17.5%

Pyro Aluminum or 999 – 5%

10% Nitrocellulose Lacquer

IMG_20231109_185028.jpg

IMG_20231109_183014.jpg

IMG_20231109_133156.jpg

Red looks good too.

What was ingredients used for it?

Posted
1 hour ago, Zumber said:

Red looks good too.

What was ingredients used for it?

It was Independence red composition.

Sr(NO3)2 – 50% Magnalium – 18% PVC – 17% Sulfur – 10% Dextrin - 5%
 

Posted

Oh I see......you have substituted parlon with pvc.

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