Dragon Eggs (Dragon Flowers)

[Mumbles]

Do you think you might be able to just tumble the wet grains after granulating to round them out and get them more dense?

[spitfire]

I tried that Mumbles, but it is really tricky. Or they stick together, or the major part breaks apart into finer dust. I found drying first and tumble with additional powder worked best for me. But there might be plenty of pyro's who have a better way!

[enanthate]

Will try to roll them further spitfire, sounds like a good idea. I only granulated them, to create very porous granules! These obviously don't make great dragon eggs.

By the way, all I have is 400 mesh spherical aluminum. Anybody knows if this is a critical detail?

[schroedinger]

Yeah you will need much carser mgal for them

[enanthate]

schroedinger, I was referring to aluminum. Not mgal!

Got 10-100mesh mgal that I will try, this is coarse enough (if not too coarse...).

[Zumber]

schroedinger, I was referring to aluminum. Not mgal!

Got 10-100mesh mgal that I will try, this is coarse enough (if not too coarse...).

if you are planning to make dragon eggs you must need to use magnelium alloy, aluminum must not work for dragon eggs.

200 mesh magnelium work pretty well for me.

[enanthate]

if you are planning to make dragon eggs you must need to use magnelium alloy, aluminum must not work for dragon eggs.

200 mesh magnelium work pretty well for me.

Check the recently mentioned compositions. They call for aluminum. And MgAl, of course.

[Yus]

Crackling flower microstars (0:38) based on CuO/Bi2O3/AlMg = 60/20/20 core composition. Sorry for unfocused camera.

 

https://youtu.be/tNnfn-2Xi-c

[Yus]

https://youtu.be/xStlYLGyZfo

[ronmoper76]

These are badass,nice stuff.

[SharkWhisperer]

These are badass,nice stuff.

Yus creates respectable stuff. All the time. Own YT channel. Good info. Shares comps, too,

Edited March 29, 2021 by SharkWhisperer

[Yus]

Thank you. I use core comp. CuO - 40%, Bi2O3 - 30%, AlMg - 30%.

[ronmoper76]

I'm definitely gonna try it. I have been searching for different ratios that work with varying amounts of Bi2O3. Its kinda pricey here to be using 75% like a lot of formulas call for.

[SharkWhisperer]

 

Wow have been offline for a few days, but here's my reply anyway... I use this same formula too. MgAl is 150 - 200 mesh. Meanwhile i found a way to get the grains less porous. After drying i sieve them to get the small material out, the bigger ones are hand-rolled in a bowl with another layer of material. This produces more dense grains. I should try coarser MgAl too, sound promising!

I'd use coarser MgAl; used to use FWC's old -60 mesh that had fines, too, and it works great. He's resized his selection and now I believe -50 and -50+100 is available--I'd probably try the latter first. 10 mesh seems too large to me, both for burn characteristics and ease of use. I think a lot of people make the mistake of using too fine of MgAl to begin with (150-200 wouldn't be my initial "go to" selection). But whatever works for you.

 

schroedinger, I was referring to aluminum. Not mgal!

Got 10-100mesh mgal that I will try, this is coarse enough (if not too coarse...).

Please see comment above--10 mesh might be a thorn in your side. The -40+100 fraction of your metal is what's doing the work. Simple to smash down with a hammer (no milling necessary) and rescreen to desired fractions...

 

Will try to roll them further spitfire, sounds like a good idea. I only granulated them, to create very porous granules! These obviously don't make great dragon eggs.

By the way, all I have is 400 mesh spherical aluminum. Anybody knows if this is a critical detail?

One thing I have never yet experienced is "porous" DEs!!! Heavy little dense bastards, they are!!! Solid. Maybe in the mixing/consolidation? You don't want to "granulate" them similar to how you might rub a ball of moist BP across a 1/4" or 1/8" screen. You can easily screen cut them, but you need to get your patty the right thickness first, and then press downwards more than rub across the screen, if that makes sense. Hot/combine prime the tops and bottoms of your slabs thickly before screening (or cutting), maybe with a spritz of acetone first to rewet the surface and help it stick, and then drop them into more hot/combined prime immediately after making them into little squares. Be generous with the prime--they work better, though for the life off me it seems that the Chicoms don't worry so much about this. Probably using H3 as prime base (haven't tried, but see no good reason to try; suggest go with what's proven in the West)... Secondary prime at leisure. Hot but slower burning than the first hot prime, but with some extra retained heat (Si and Al or MgAL extra). Priming will definitely depend on whether your're making gerbs (gorgeous) or aiming for crackle core stars (now priming becomes critical). The priming approaches for different uses are not interchangeable, for obvious reasons besides working with a difficult-to-ignite comp.

 

Small sizing is generally good with DEs--maybe you'll figure a way but my DEs are around 1/8" (3 mm?) before priming in general, for ground effects and for aerials. They work great. Can make themmuch bigger, but with my MgAl mesh sized, they'd likely just blow apart (probably blind). Still amazes me that the Chicoms make consistently functional (and decent) perfectly round primed DEs that are only 2mm diameter max. But they're likely using the better characterized (and toxic--how often are imported 1.4g devices actually dissected and tested by the supernanny CPSC?) lead comps to start with, and have an endless labor supply for when the first group of 12-year-old "technicians" occasionally go boom ("grease fire in kitchen, no ploblem! Evlyting unda contlow!").

 

400 mesh spherical sounds big--even larger than Al in Tannerite. That's an average particle size of 37 microns, which is rather large for spherical. Might work. Might be an impediment. Everybody's seen them, but sometimes it's useful to review the mesh-to-micron sizing chart (https://www.skylighter.com/blogs/fireworks-information/mesh-to-micron-conversion-chart ), keeping in mind that you're referring to average size, and each batch, even from the same company will vary on either side. You can't screen sort 5 vs 40 micron--it's all dust. I use 5 micron spherical Al addition to my DE mix, with great results. It keeps the fire alive. Larger would probably work. 37 micron average? Wouldn't be my "go to" add-in Al size, but definitely worth comparing.

 

Save a lot of money by swapping (to your chosen extent) the classical 75% Bi₂O₃ for CuO (and vice versa). DEs will work essentially identically with this change (you might need to tweak your other chems, slightly, but not much). And at $20/lb vs $8/lb, I prefer using more CuO than that pretty yellow (and dense as hell) bismuth.

 

I used to add and add and add NC lacquer until I got a final estimated NC concentration of 5%, but seriously question if you need so much--I get solid DEs that perform well using just a single thorough wetting with 5% double-base/acetone (maybe just a little extra for good luck--it dries fast anyways). Turn a 2 hour production into a 45 minute production (not counting clean-up and secondary priming). And prime them lil' bastards well. I step prime with a hot 50:50 comp/hot prime mix (with a few % silicon and Al, Mg/Al if it's closer) and then a slower cover prime, also with silicon and another metal, just because, and they never fail to ignite. I don't bother with roughing the surface by including sawdust or diatomaceous earth--just never found it necessary.

 

Easy peasy. Chris at FWC is selling a variety of screen-sized MgAls these days. I used to love his -60 (no lower cutoff, so plenty of fines), but given the importance of your MgAl sizing, my next batch will be more tightly regulated--likely his marketed -50+100 or so. Those using -200 MgAl in crackle kinda catch my attention, but if it works, great. Once you have all the parameters pinned down, it's hard to screw it up and fast to whip up a batch... It dries quickly and I prime slabs wet before screen or hand-cutting. If this makes you nervous, then have some acetone at hand and you can back up a few steps no problem (if spraying, make sure it doesn't dissolve the sprayer contents--various plastics used in the sprayer vs the bottle...). And if you need even more time, then add some MEK (methyl ethyl ketone) from any big box store (Home Depot etc), which will slow the evaporation rate quite a bit. I've personally never found this necessary. NC/acetone comps tend to get "sticky", and some have suggested that adding 10% or so of alcohol (ethanol, isoprop, methanol/denatured...I don't care), can reduce this, though I've never found it necessary.

 

Crackle away!!! Birth them thar Dragons!!!

 

p.s. Yus has on several occasions posted the size of his MgAl and other chems used in DEs and similar crackle comps, so please search/read these before you bug him with a "hey, what size MgAl do you use" query that you can answer for yourself. If he changed it from earlier postings, he'll let you know. TIP: You'll need your handy micron-to-mesh table to retranslate Yus' descriptions back to mesh size...

Edited March 30, 2021 by SharkWhisperer

[Twesla]

Edit: the original formula I used was 70% bismuth trioxide, not 75%

 

I had trouble with dragon flower compositions where the cores were popping with a loud singular crack, but once rolled in a smoldering composition would be muffled and would spall off burning chunks. When I tried simply priming them, the pops would have such a long and unpredictable delay that theyd make it to the ground while exploding all over the place like a roll of black cats. I included potassium dichromate in the inner prime, and bound primes with NC, alcohol and water. The formula I used was 75/15/10 Bi2O3, CuO, Mg/Al (80-200mesh) +5% 5 micron Al. I was reluctant to try anymore because I use my bismuth oxide for strobes that work really well.

 

I decided to revisit DEs in order to try a few things. I made some using 40-100 mesh magnalium by crushing and screening FWCB 10-50 mesh magnalium and adding +5 120-325 mesh spherical Ti. I cut them into quarter inch squares and primed them with 70%KClO4, 12%Red gum, 10%Si, 5 potassium dichromate and 3%-325Mg/Al followed by Monocapa prime and BP with alcohol, water and water, respectively. They still have a long unpredictable delay, and some individual stars pop twice.

 

I finally tried a ten gram batch with everything the same, except using 230-325 mesh Mg/Al, and Ekart 120 atomized Al instead of 5 micron Al. I also tried making 10 grams of the Chinese crackle based on the formula on FWCBs website (66 CuO, 28 Mg/Al, and 6 Bi2O3). Both were bound with NC and screen sliced through an 8 mesh screen. I havent primed any, but the regular high bismuth ones are the best Ive made so far, all popping with if a split second of each other and popping louder than ever. The high copper oxide ones make more of a poof than a pop, so Im scrapping that idea.

 

For me the 230 mesh Mg/Al and smaller granule sizes have been the trick to getting these to create the effect I was looking for. Im thinking of waxing them to keep the prime layers from killing those intense pops.

Edited June 14, 2021 by Twesla

[SharkWhisperer]

I had trouble with dragon flower compositions where the cores were popping with a loud singular crack, but once rolled in a smoldering composition would be muffled and would spall off burning chunks. When I tried simply priming them, the pops would have such a long and unpredictable delay that theyd make it to the ground while exploding all over the place like a roll of black cats. I included potassium dichromate in the inner prime, and bound primes with NC, alcohol and water. The formula I used was 75/15/10 Bi2O3, CuO, Mg/Al (80-200mesh) +5% 5 micron Al. I was reluctant to try anymore because I use my bismuth oxide for strobes that work really well.

 

I decided to revisit DEs in order to try a few things. I made some using 40-100 mesh magnalium by crushing and screening FWCB 10-50 mesh magnalium and adding +5 120-325 mesh spherical Ti. I cut them into quarter inch squares and primed them with 70%KClO4, 12%Red gum, 10%Si, 5 potassium dichromate and 3%-325Mg/Al followed by Monocapa prime and BP with alcohol, water and water, respectively. They still have a long unpredictable delay, and some individual stars pop twice.

 

I finally tried a ten gram batch with everything the same, except using 230-325 mesh Mg/Al, and Ekart 120 atomized Al instead of 5 micron Al. I also tried making 10 grams of the Chinese crackle based on the formula on FWCBs website (66 CuO, 28 Mg/Al, and 6 Bi2O3). Both were bound with NC and screen sliced through an 8 mesh screen. I havent primed any, but the regular high bismuth ones are the best Ive made so far, all popping with if a split second of each other and popping louder than ever. The high copper oxide ones make more of a poof than a pop, so Im scrapping that idea.

 

For me the 230 mesh Mg/Al and smaller granule sizes have been the trick to getting these to create the effect I was looking for. Im thinking of waxing them to keep the prime layers from killing those intense pops.

First things first. How big were your DEs cut before you primed them? A common problem is folks cut them too big on their first batch or two. Ah sheesh, I see you were cutting them 1/4". That's huge. Your later 8-mesh is closer to what you want, but you'll always get more precise DEs with knife cutting vs screen cutting. These you want smallish, the exact size depending to some extent on how big your MgAl is. Take apart a Chicom crackle ball and you'll see the little tiny perfectly round primed mouse turd crackle eggs that can't be 2 mm in diameter, even primed!

 

Waxing? Now you're reinventing the wheel without having fixed other problems first. A bandaid to treat a headache...

 

I don't even know what to say about your second "DE" formula. Where'd you get that one from? What's the purpose of the Ti? Try experimenting with Ti after you get your basic DEs working right. Quarter inch squares are about 2x too big (linearly, and 4x the volume) for that MgAl size.

 

And leave out the toxic and highly carcinogenic dichromate. It serves no purpose and is entirely unnecessary. And 5%??? That's only for treating pure Mg and as a rarely used catalyst.

 

You've made a lot of substitutions to the FWC-derived crackle recipe.

 

My friend, in short, you are all over the map. Jumping from one idea to another and changing multiple things at once. This is often self-defeating. And tiring.

 

You're in the general ballpark but you need to be more methodical and stop and evaluate the probable reasons for why things aren't working out the way you'd like, then reviewing past threads or asking questions before you start dumping Ti in your DEs, poisoning yourself with dichromate, changing metals, and waxing (?!?) your stars... Slow down. Think. Ask. Come up with logical solutions instead of guesses. Do this first. Then act. And please stop guessing. The fix is probably a hell of a lot less complicated than you're making things.

Edited June 14, 2021 by SharkWhisperer

[Twesla]

I apologize, I should have been more clear. I listed a lot of things I tried in the past to point out my mistakes, and the poor results I got by making those mistakes. Dragon eggs were some of the very first things I tried to make, before stepping back and deciding to do some reading.

 

As for the additions, I didnt make any substitutions to the FWCB formula for Chinese crackle.

https://www.fireworkscookbook.com/firework-recipe/crackle-microstars-chinese/

I dont take using potassium dichromate lightly at all from PPE to clean up, and I avoid it at all costs now. The reason I used it in the first place was that I was trying to make dragon flowers based on this:

https://www.amateurpyro.com/forums/topic/5072-dragon-eggs-dragon-flowers/

The addition of some spherical titanium was something I wanted to try based on one of Ned G.s YouTube videos about priming dragon eggs, where he shared the formula and mentioned that he added 5% spherical Ti for spark effect.

https://m.youtube.com/watch?v=Gor0Sqi29To

I was considering wax after reading about it under the dragon egg section on the site below.

http://www.creagan.net/fireworks/compositions.html#dragonseggs

 

Thank you for your feedback regarding the idea of waxing them, if it sounds dumb then it must be unnecessary. Ultimately, Im very sorry for oversharing all my past mistakes. I really just wanted to share that after I made those errors I ended up trying again recently and finding success in 1/8 bits by using 230mesh magnalium in the formula that requires 70% bismuth oxide, and when I tried making the Chinese cracking microstars from FWCB so that I could compare the two, the latter were inferior in my opinion.

Edited June 14, 2021 by Twesla

[Twesla]

Also I want to thank you for confirming to me that using chromates in crackle is unnecessary, particularly given the high risk it poses. In addition to the dragon flower formula that includes potassium dichromate, I used to think it was a necessity when using water to bind prime layers to crackle based on what I read here

http://www.pyrobin.com/files/Bismuth%20Crackle%20w-notes%20by%20Ned%20G.pdf

The rationale behind using 5% in the inner prime was that I decided to use the same inner prime from the dragon flower formula instead of making a solution of potassium dichromate and subsequently aerosolizing tiny droplets of it from a spray bottle, because to me that seemed riskier and more likely to spread contamination, as well as creating extra liquid waste that would need proper disposal. But maybe thats stupid of me to believe dry powder wouldnt create more air born particles containing hexavalent chromium. Either way, eventually omitting it altogether didnt seem have any effect. Im glad to hear someone with experience confirm to me that its completely unnecessary.

[SharkWhisperer]

Also I want to thank you for confirming to me that using chromates in crackle is unnecessary, particularly given the high risk it poses. In addition to the dragon flower formula that includes potassium dichromate, I used to think it was a necessity when using water to bind prime layers to crackle based on what I read here

http://www.pyrobin.com/files/Bismuth%20Crackle%20w-notes%20by%20Ned%20G.pdf

The rationale behind using 5% in the inner prime was that I decided to use the same inner prime from the dragon flower formula instead of making a solution of potassium dichromate and subsequently aerosolizing tiny droplets of it from a spray bottle, because to me that seemed riskier and more likely to spread contamination, as well as creating extra liquid waste that would need proper disposal. But maybe thats stupid of me to believe dry powder wouldnt create more air born particles containing hexavalent chromium. Either way, eventually omitting it altogether didnt seem have any effect. Im glad to hear someone with experience confirm to me that its completely unnecessary.

Aye sheesh, I forgot about that document. Lloyd has tons of experience in making crackle and is a bright dude, but I've never understood his direction for including dichromate in the aqueous prime coating. It's usually used for coating pure Mg that is very reactive in water solutions. MgAl not so much. That 5% Al... Oh my, that could form reactive amides with nitrates in an aqueous environment. That's why we (I don't see the need) include boric acid in Al/nitrate mixed comps that are water (dextrin/SRGS...) bound. To prevent exothermic reactions that could overheat and cause problems. Unlikely with this DE mix. There is no nitrate involved until final prime. I do not say impossible, especially if ingredients are impure or poorly characterized. But unlikely. Some folks include boric acid in their water-bound Al/nitrate star comps, though I have never heard of somebody treating Al with dichromates for any reason--only pure Mg powders. And also not MgAl.

 

That said, I dual prime my DEs first with a hot perc/charcoal-based 9% red gum- and 3% silicon- containing prime using 91% IPA as solvent for faster drying, and don't really worry about that 9% water that it contains. I roll balls of comp over hot prime and then dust the patty with a health dose of hot prime on top, and again just after cutting to prime the sides. Then they get bounced around again in a bowl with a little more prime til it's uniform, with some solvent spritzes in between. Cover (2nd/top) prime is just BP mill dust goosed up with a little gum and metal (ever had an issue and the eggs scream loudly :+} also using IPA. Usual 70% will also work, but I prefer less water for faster drying. Impatience or laziness? Don't care. Water's pretty much free but alcohol's pretty cheap if you aren't collecting cans for food money.

 

I also use a reduced-Bi formulation with 35% bismuth trioxide to 40% copper oxide, 20% MgAl -60 (like the mixed mesh; FWC currently sells -50 and -50-100, I think...), and 5% Al (both spherical 5 micron and -325 mesh (around 44 micron) seem similar--just keep the heat up while the smoulder turns to "pop". You could possibly go lower with the expensive bismuth compound and still get great results. Probably others have tried this.

 

Was dumping tons of NC lacquer into my mixes until I realized that less worked ok, too--down from 5% NC (mass proportion in final solid comp) to around 2% didn't cause any issues and made life easier by shortening worktime waiting for acetone to evaporate. Started dabbling into alternative binders (phenolic resin, cheap, for one), but got side-tracked. I would not imagine that the Chicomms use NC in their crackle, but maybe...

 

Anyways, good luck. For me, the "hardest" part of DEs isn't the comp or priming them, it's deciding when the batch is ready to get rolled out/primed/cut, being prepared so there are no delays, and working steadily and quickly. That said, there are probably workarounds to acetone's fast evaporation. You can add methyl ethyl ketone (MEK from Home Depot, right next to the acetone; or cheaper undefined "paint thinner") to your acetone to slow evaporation and give you more working time. But I find this unnecessary. It also helps during priming to have a very fine-misting aerosol spray bottle that can handle either alcohol (never a problem) or acetone to keep your patty "moist" if it's drying out faster than you'd like. Used while swirling stars/eggs just before dumping on more prime too. Keep in mind that while the spray bottle might be labeled PTFE or similar that is resistant to acetone, the internal sprayer components might not be solvent-resistant and clog up you. And that can suck.

Edited June 15, 2021 by SharkWhisperer

[nordicwolf]

Did YUS youtube channel get taken down? I cannot find it. Also there used to be several videos on this forum that are no longer available.

 

He had vids and compositions of gently popping crackle / flowers. I want to try to make those or something like that.

 

I was also curious if in his DE comps in this thread what prime he used if any. Thanks.

 

oh, and @sharkwhisperer, will you please share the exact details of your "hot perc/charcoal-based 9% red gum- and 3% silicon- containing prime using 91% IPA". What are the ratios of perc, charcoal (what mesh? airfloat?). Then to that 9% red gum and 3% silicon. Thanks!

Edited July 24, 2022 by nordicwolf

[SharkWhisperer]

Did YUS youtube channel get taken down? I cannot find it. Also there used to be several videos on this forum that are no longer available.

 

He had vids and compositions of gently popping crackle / flowers. I want to try to make those or something like that.

 

I was also curious if in his DE comps in this thread what prime he used if any. Thanks.

 

oh, and @sharkwhisperer, will you please share the exact details of your "hot perc/charcoal-based 9% red gum- and 3% silicon- containing prime using 91% IPA". What are the ratios of perc, charcoal (what mesh? airfloat?). Then to that 9% red gum and 3% silicon. Thanks!

N-Wolf, notes are about 1500 miles away, but had some drafts on my puter. There's quite a bit of latitude with prime comps--going 1-2% off on large-fraction chems probably won't make much of a difference in end result, but one hot perc prime I love for step priming DEs & made a ton of was as follows:

 

Hot Perc Prime

71% Perc

14% Charcoal (half generic hardwood airfloat/half ERC)

9% Red Gum

6% MgAl -200 mesh

+3% Si 200 mesh

 

Outer BP Prime:

67% KNO3

14% charcoal (same mix as above)

9% S

5% MgAl -200

5% Red Gum

+5% Si -200

 

 

*Applied with 91% IPA because I appreciate faster drying

*Have also used all commercial airfloat C alone to good effect but I added some hotter cedar because I had a bunch on hand. Sometimes use willow C. Works great.

*MgAl to heat things up a little; I've used a broader size-range -60 before too, to good effect.

*Red gum at 5% is probably sufficient for binding primer; I added more to hot prime because I had room and I know it's going to bind solidly. Want to try Vinsol.

*Si to melt into a hot molten glassy slag. Some recipes use up to 10%. I use what I found burns sufficiently hot and ignites reliably. To me the Si-slag from the outer prime is important in guaranteeing the slightly harder-to-ignite hot inner prime takes fire. Outer prime BP base fires up easily, especially with that S and a bit of hot charcoal. Once that perc prime ignites, nothing is going to extinguish it easily.

*Some like bumps on the outer prime from adding diatomaceous earth or sawdust for easier ignition. My outer prime layer is ugly and bumpy without and has never needed it. Plus, DiE doesn't really burn so well and untreated sawdust isn't a favorite fuel although you don't really need to use much.

*I would imagine you could randomly change any ingredient up 1-2% and the next down 1-2%, or vice versa, and you would probably never know. Except Si, 3-5% is on the low-moderate range so I wouldn't want to use much less. These are well-oxidized comps that have hot fuels and do the job.

*Everything screen-mixed through 20 mesh until uniform, 3x usually does the trick.

*I've stored buckets of both as do-it-all primes for many months without special consideration except away from open flames and they always work well.

*The little bit of MgAl in my BP outer prime provides some extra heat energy without impeding ignitability. I sometimes add Al or MgAl to my BP when making match, just because. I speculate that the metal is particularly important on the inner prime for uniformly and rapidly transferring a bunch of heat energy to the entire DE surface nearly at once.

*You could likely find a decent Al to sub for the MgAl to good effect, but I like MgAl.

[cmjlab]

Anyone have luck getting plain DE to ignite out of a shell?

 

I tried all sorts of prime, leaving out Potassium Dichromate when called for, but always had 50% ignition at best and many blind shells (using non boosted, BP burst). I then tried including Dichromate on 1st hot prime layer, and got much better if ignition - but not more than 75%(ish).

 

I have not tried rolling a charcoal streamer over them yet, as I wanted to emulate the "dark" open, followed by large DE flower sphere.

 

Charles

[Pyrophury]

Anyone have luck getting plain DE to ignite out of a shell?

 

I tried all sorts of prime, leaving out Potassium Dichromate when called for, but always had 50% ignition at best and many blind shells (using non boosted, BP burst). I then tried including Dichromate on 1st hot prime layer, and got much better if ignition - but not more than 75%(ish).

 

I have not tried rolling a charcoal streamer over them yet, as I wanted to emulate the "dark" open, followed by large DE flower sphere.

 

Charles

 

I came up with my own prime for this purpose, it was something like:

Potassium Perc. 70

Red gum / Phenolic Resin 10

Silicon (very fine powder) 10

Silicon dioxide (Very fine powder) 5

Dextrin 5

 

It needs step priming with green mix BP, but once it ignites it creates a white hot slag that sticks to the star, even when using flash powder burst. The silicon dioxide is very important, without this the molten silicon just beads up on the surface and doesn't form a slaggy shell around the microstar.

 

[cmjlab]

Pyrofury, that's pretty good ignition. If you had to guess, do you think most of them ignited?

 

I also didn't read back through all the pages of this thread, but what DE comp did you use? And what form of NC lacquer?

 

I bought a couple more pounds of Bismuth Trioxide to make another batch of DEs but was gonna test some methods first to see what gets the best ignition from a shell.

 

Thanks, Charles

[Pyrophury]

Pyrofury, that's pretty good ignition. If you had to guess, do you think most of them ignited?

 

I also didn't read back through all the pages of this thread, but what DE comp did you use? And what form of NC lacquer?

 

I bought a couple more pounds of Bismuth Trioxide to make another batch of DEs but was gonna test some methods first to see what gets the best ignition from a shell.

 

Thanks, Charles

 

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.