Almostparadise Posted June 21 Posted June 21 I'm using 37.5 bismuth trioxide 37.5 black copper oxide 25.0 Magnalium 100-200 mesh Bound w NC lacquer I put my torch on them it takes a minute before it starts to Glow and then it gives an extra loud bang. A lot more than a crackle. The problem is I can't get them to light. They take so long to heat up that any prime I use burns out well before they're ready. I made them in the past and they were much easier to light. I was making them for star cores.
pyrojig Posted June 21 Posted June 21 That comp looks off to me. Also try finer mesh magnal . Course will take lots of heat to ignite. Step prime etc. nc laq needs to be pretty thick honey like. And comp well mixed , then screened or cut small 1/8” or smaller
Zumber Posted June 21 Posted June 21 (edited) 42 minutes ago, pyrojig said: That comp looks off to me. Also try finer mesh magnal . Course will take lots of heat to ignite. Step prime etc. nc laq needs to be pretty thick honey like. And comp well mixed , then screened or cut small 1/8” or smaller Agree with magnelium mesh size 200 works well for crackling stars and it should be 50:50 I disagree with NC consistency. Thicker NC creates problem if crackling star is tested in shell and not in a fountain. The consistency of NC should be like cooking edible oil. Add more acetone in it if your NC is too thick. Also try out commercial NC if you are using homemade. Try out again with 200 mesh magnelium ( 50:50) and thin consistency of NC. Post your response. Edited June 21 by Zumber
Almostparadise Posted June 21 Author Posted June 21 I don't have 200 mesh. I'll try to get more 200 mesh out of the stuff I have now. Otherwise I have 325 mesh. I made the NC from double base. It's like honey. I put these through a garlic press and primed them w Jopetes crackle prime. I'll post back w results ty!
Zumber Posted June 21 Posted June 21 Star seems to big in a size. NC should be of good quality and thinner consistency. If you put unprimed stars in loose bp and ignite bp it should be ignited and perform on ground. Unprimed star size should be 1 mm to 2 mm maximum. 1
Almostparadise Posted June 21 Author Posted June 21 (edited) I know what the problem is. I was using magnesium and not mg/al. The containers are the same. I've had the magnesium for a long time and don't use it. I was moving things around the other day so it ended up right next to the mg/al. Foolish operator error that could have ended up a lot worse. So at least there's that. I should have gotten rid of it a long time ago. Edited June 21 by Almostparadise Punctuation
Zumber Posted June 22 Posted June 22 Anyways prepare new batch and remember changes to make as stated in previous posts. 1
pyrojig Posted June 22 Posted June 22 @zumber your advise is good. But I have seen to thin of nc not be enough to get combustion to the temp needed for the ‘glow’ ignition of the metal. Thinning with acetone is needed as mixing progresses ( I left that detail out) . I have in past had success, mixing magnesium and aluminum 50% each. They have to be a pretty intimate mixture to work and very fine like suggested above 200 to 325 mesh. Wouldn’t suggest doing it that way. The best results came from Magnal mixed with some very fine atomized aluminum to boost the effect which gave it louder bang. But don’t start with that formulation (with aluminum) for the first tests of that comp.
Zumber Posted June 22 Posted June 22 Binder affects star performance a lot. Too thick NC represents more cotton nitrate is dissolved in lacquer. I have very good experience of this. I have prepared crackling stars with thick consistency of NC and tested it in a fountain as unprimed crackling stars....it has performed damn well next day I primed same stars and tested it in a shell and most of stars failed producing loud sound plus ignition. After that I made change In NC consistency and primed star with same prime and it worked danm well in a shell and fountain with very loud sound and ease of ignition too. This time sound was loud even if shell exploded at high altitude than testing in fountain. So since that day I am preparing with same changes since 5 to 6 years without a problem.
pyrojig Posted June 23 Posted June 23 Excellent, thanks for sharing your experience. So your alteration are thinner nc( shotgun powder , home made nc, or commercial grade nc?) thin syrup consistency, and what comp did you have your best results from ?
Zumber Posted June 23 Posted June 23 5 minutes ago, pyrojig said: Excellent, thanks for sharing your experience. So your alteration are thinner nc( shotgun powder , home made nc, or commercial grade nc?) thin syrup consistency, and what comp did you have your best results from ? No I have commercial NC I use it everytime. It is sold as very thicker consistency exact ratio is not known. I re-experimented with it because it was creating problems with stars. I am using red lead based crackling stars with same ratio like standard black powder. 75/15/10 red lead/ magnelium /cupric oxide. Usually 10 percent cotton nitrate is dissolved in 100 ml acetone but I dont know what percentage manufacturer has dissolved but it was pretty thick like honey. I added more acetone to thin it bit more and made 1 mm to 2 mm granules using wire mesh screen.
pyrojig Posted June 24 Posted June 24 I think commercial is 25% … don’t quote me , I have to check my bottle for %’s. red lead gives great effect and is reliable . Most folks are scared of lead , but it is a staple comp for D.E.’s . I have seen how these stain concrete and glass lol , it’s hard to remove these stains .
Mraliksr Posted October 27 Posted October 27 On 6/22/2024 at 8:50 PM, Zumber said: Binder affects star performance a lot. Too thick NC represents more cotton nitrate is dissolved in lacquer. I have very good experience of this. I have prepared crackling stars with thick consistency of NC and tested it in a fountain as unprimed crackling stars....it has performed damn well next day I primed same stars and tested it in a shell and most of stars failed producing loud sound plus ignition. After that I made change In NC consistency and primed star with same prime and it worked danm well in a shell and fountain with very loud sound and ease of ignition too. This time sound was loud even if shell exploded at high altitude than testing in fountain. So since that day I am preparing with same changes since 5 to 6 years without a problem. Greeting to all with thanks, kindly note my crackling or dragon eggs not getting ignition easily burn and red like iron red in heat not explode binding with nc lacquer lead tetraoxide 75 maganlium 15 copper oxide 10 nc 10 thanks for all
Zumber Posted October 27 Posted October 27 You may don't need to post same questions again if it is already posted in another topic. Have wait until you get response from someone.
cmjlab Posted October 27 Posted October 27 I must have missed the other post, so I will respond here.... I haven't tried Lead Trioxide, all mine were Bismuth Trioxide based, so I wouldn't call me a reliable source of firsthand knowledge on these. However, I wonder what mesh Mg/Al you are using and whether that plays a factor in lead Dragon Eggs / crackle, or not? DE / crackle is a routine source of frustration for people first trying it out, and usually takes a few batches to get it right.⁰ In Bismuth DE / crackle, NC content and Mg/Al fineness plays large factors in how easily they ignite. A good hot prime which ignites the entire surface and provides a high thermal energy has also discussed as a factor. Lastly, for me, I've had the best luck with getting individual DE / crackle to ignite when using a prime that contains Potassium Dichromate. I don't knowbwhat factor plays into it, I've just noticed over several batches that they had the best ignition rate when fired as individual stars from shells and mines. I'm sure someone could prob find a flaw in my process, but I've stuck with it.
FrankRizzo Posted November 11 Posted November 11 On 10/27/2024 at 11:16 AM, Mraliksr said: Greeting to all with thanks, kindly note my crackling or dragon eggs not getting ignition easily burn and red like iron red in heat not explode binding with nc lacquer lead tetraoxide 75 maganlium 15 copper oxide 10 nc 10 thanks for all That does not seem to be an accepted formula. Please try again with the following formula that is known to work: lead tetraoxide 37.5 maganlium 25 copper oxide 37.5 nc (double base) 10 1
Mraliksr Posted November 12 Posted November 12 6 hours ago, FrankRizzo said: That does not seem to be an accepted formula. Please try again with the following formula that is known to work: lead tetraoxide 37.5 maganlium 25 copper oxide 37.5 nc (double base) 10 Thanks sir, okay i will soon try this formula but i have no double base Nc just nc cotton thanks for your guidance.
FlaMtnBkr Posted November 14 Posted November 14 If they glow red and don't pop, the metal is too big and needs a finer mesh (some or all, takes experimenting). If they crackle with a bunch of small pops and many times a big chunk never lights, the metal is too fine and needs to be coarser. They are definitely a balancing act and can be frustrating as the metal size, DE size, NC content, and priming all need to be tuned together. But they are pretty impressive when they are working right. I also always had the best luck with the 37.5/37.5/25 ratio when using bismuth plus it was cheaper than the other popular formulas.
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