Firecracker Powder (1980s)

[nordicwolf]

Back in the late 1970s I had friends who got stuff in San Francisco's Chinatown. Most often they had Thunderbomb firecrackers but also Panda, Red Lantern, and other plain red firecrackers (the plain red ones were the loudest). What they all seemed to have in common was a very fine bright silver flash powder.

 

Does anyone know the composition of that Chinese firecracker flash powder? It was much brighter, very silvery in color, and they popped with a very bright flash. It would not appear to be a powder made from german dark or Indian black aluminum - those are too dark.

 

Any ideas? Thanks.

[cmjlab]

I know the obvious answer would include at least a portion of bright aluminum, which could cheapen the flash powder composition yet still be plenty effective for commercial firecrackers

[pyrokid]

Economics has been known to play a role in Chinese formula development. I would expect that a classic firecracker composition would be somewhere along the lines of 7-3-1 or 5-3-2 KClO4-Al-S. Definitely some bright aluminum and I would expect a wide particle size distribution with varied morphology.

[mx5kevin]

We have a tradition of this in Europe. I started this hobby 15 years ago to professionally reproduce these firecrackers. I read a lot of professional documents on the subject, and used a lot of money and raw materials for the experiments. These are the extremely sharp loud and very bright white light firecrackers with minimal on average 0.3g flash powder (100 pcs/box Pirat Match Crackers the most frequent version). Or in P1, P2 technical category with 0.5g flash the much stronger version.

 

Detailed description here: Testing flash powders for homemade firecrackers

 

For these, only potassium perchlorate-based flash powder are suitable, which is safe and of adequate quality. Everything else is either weak or dangerous. The only alternative are KClO3 what are dangerous. I have tried almost all known oxidizer for this purpose, there is no other alternative to it which produces the required sound (sharp sound frequency with minimum 120 dBA@15m) sharpness/light quality. Everything else is have much more duller sound regardless of the amount of used flash. The best flash powder for these firecrackers are the KClO4 Al S 50 40 10% from 3-7 micron pure Dark aluminum for under 10g firecrackers, and 50:50 mixed blue 30 micron must keep under 40 micron the aluminum and 3-7 micron Dark Al for larger salutes (to get huge flash effect this is important). The maximum power cannot be achieved without sulfur. With less aluminum and more potassium perchlorate: If the aluminum are coarser the composition will be much more slower, the same fuel rich technique are used in photoflash powders, if more sulfur used it cools and slows down the mixture (see the M46 military formula, or the photoflash powder compositions what are the brightest flash powders). The aluminum powder does not need to be protected here with boric acid. With magnesium are dangerous, 50:50 magnalium what coated with 5% linseed oil and dried are a alternative. But much more sensitive for friction. Paint grade firefly bright aluminum the worst that can be used for this. Flying the particles strongly in the air, the grain size is not suitable at the factory, the powders not dense enough either.

 

The delay are rammed Glusatz (Glühsatz) Barium nitrate 75.5%, Charcoal (airfloat) 10%, Sulfur 10%, Meal-D 3% (3-5%) (KNO3 C S 75/15/10 classic), CMC 0.6% (for granulation to make it less dusty must dissolved in water), in the case of Match Crackers with some match head composition on the head. Or simple Visco fuse in most cases.

 

The best paper tubes at home for this are made from copy paper glued with 40% sodium silicate (water glass solution). And the right wall thickness is very important. If it is too thin, it will not be loud enough and the paper will burn out. Exaggerated thickness is just as bad. But thicker strong, rigid, solid, paper tubes is very important. When filled into the paper tube the flash powder must have a uniform density loose structure.

[mx5kevin]

If the powder is brighter it is usually magnalium used, if darker in this case aluminum are used. A little sulfur is almost always used in these types of firecrackers. Not the classic 70/30 or 50/50 compositions are used in this mini crackers. These types of firecrackers are better known in Europe than in America. Germans, in Balkan countries, Poland, in homede, groups they are made the best reproductions.

 

KClO4 Al S firecrakers

 

Here with 0.1-0.2g KClO4 Al S 50/40/10% in a mini firecracker check out the beer can test. The used metal powder, method of preparation matters a lot. In another video where another user tested 1g flash 6/3/1, 7/2/1 see the difference between the two. 0.1g from this and 1g from that. I took apart the beer can in the same way with the small 0.1-0.2 gram firecracker compared with the 1 gramm can of coke what are another user are tested. And the quantitative difference is five-fold, ten-fold.

 

 

Flash Powder Comparison 1) 1g KCLO4 / AL 2) 1g KCLO4 / AL / S 3) 1g KCLO3 / AL 4) 1g KCLO3 / AL / S

 

 

 

 

Potassuim chlorate flash verses potassium perchlorate flash (potassium perchlorate based are the safest loudest)

 

 

Edited May 12, 2023 by mx5kevin

[mx5kevin]

I can say for sure that it is not Paint grade firefly bright aluminum what are 45 micron, and not the same aluminum with finer particle size, the structure of the powder is not dense enough either. The difference in grain size is many times higher what is needed. With 40 micron aluminum it would burn slow like thermite. 3-7 micron aluminum (with aluminum the particle size must keep under 7 micron) or -325 to -400 (under 40 micron) mesh 50:50 magnalium alloy or much more finer are used in these firecrackers. Magnalium is more reactive than aluminum and for flash working with a much larger particle size this powder are have a light gray color, slightly silvery but not firefly. The powder is dense. The most reactive would be purely with -325 mesh or much more finer magnesium but this is too sensitive for friction, costly, have a little bit less bright light effect (or zero flash effect in larger sized firecrackers) as the aluminum or magnalium version its use is not typical. It is not stronger, but the same effect can be achieved with a larger particle sized metal powder.

Edited May 13, 2023 by mx5kevin

[Zumber]

Back in the late 1970s I had friends who got stuff in San Francisco's Chinatown. Most often they had Thunderbomb firecrackers but also Panda, Red Lantern, and other plain red firecrackers (the plain red ones were the loudest). What they all seemed to have in common was a very fine bright silver flash powder.

 

Does anyone know the composition of that Chinese firecracker flash powder? It was much brighter, very silvery in color, and they popped with a very bright flash. It would not appear to be a powder made from german dark or Indian black aluminum - those are too dark.

 

Any ideas? Thanks.

https://link.springer.com/article/10.1007/s10973-020-09707-7

Read this research paper it mentioned firecracker formula....I never trust using perchlorate and chlorate in flash for safety reason. still we use potassium nitrate based flash powder.

[mx5kevin]

https://link.springer.com/article/10.1007/s10973-020-09707-7

Read this research paper it mentioned firecracker formula....I never trust using perchlorate and chlorate in flash for safety reason. still we use potassium nitrate based flash powder.

 

Experimenting with potassium nitrate and aluminum is completely unnecessary. The result will be very poor. Either it is a completely different product, or the person who wrote it has never made a flash thunder firecracker in his life. Potassium nitrate needs minimum with -325mesh magnesium to be successful for firecrackers. But even so, it doesn't even come close to that quality. KClO4 are a much more stronger oxidizer than KNO3 or any other nitrate. I have been looking for a similar alternative for 15 years and I have tried all available options. Oxidizers what tested: KClO3, Ba(ClO3)2, NH4ClO4, Na2S2O8, K2S2O8, KNO3, NaNO3, Ba(NO3)2, Sr(NO3)2, BaSO4, KMnO4, with 3-7 micron aluminum and with reactive -400 mesh fine magnesium. If someone needs that extreme loud bang with extreme white light quality, they won't find an alternative. KClO3 is not a good alternative either, the only alternative that brings that quality, but with high friction sensitivity . Possible to put a lot of things in it that work, but the quality won't be like that.

[Zumber]

 

Experimenting with potassium nitrate and aluminum is completely unnecessary. The result will be very poor. Either it is a completely different product, or the person who wrote it has never made a flash thunder firecracker in his life. Potassium nitrate needs minimum with -325mesh magnesium to be successful for firecrackers. But even so, it doesn't even come close to that quality. KClO4 are a much more stronger oxidizer than KNO3 or any other nitrate. I have been looking for a similar alternative for 15 years and I have tried all available options. Oxidizers what tested: KClO3, Ba(ClO3)2, NH4ClO4, Na2S2O8, K2S2O8, KNO3, NaNO3, Ba(NO3)2, Sr(NO3)2, BaSO4, KMnO4, with 3-7 micron aluminum and with reactive -400 mesh fine magnesium. If someone needs that extreme loud bang with extreme white light quality, they won't find an alternative. KClO3 is not a good alternative either, the only alternative that brings that quality, but with high friction sensitivity . Possible to put a lot of things in it that work, but the quality won't be like that.

For My Fireworks Shells I am using Pot nitrate flash since 22 years with no problem....Though I have not made firecrackers out of it but I am very confident our country uses Nitrate based flash. Lots of members are present here from my country they are very experienced too.

[mx5kevin]

For My Fireworks Shells I am using Pot nitrate flash since 22 years with no problem....Though I have not made firecrackers out of it but I am very confident our country uses Nitrate based flash. Lots of members are present here from my country they are very experienced too.

 

Some larger commercial nitrate bangers use 5 grams of KNO3 Mg, but they are completely different product. They work perfectly well, but the sound is not that sharp. The KClO4/Al/S (50/40/10) are an extremely strong flash powder. Firecrackers made from it are extreme. In larger sizes, the factory setup are not using the most powerful flash powder what possible to make. It might be too strong for someone in the amateur setup, but others might want it just like that. In very small sizes like the 100 pcs/box with 0.3g flash Pirat or Mini Pirat firecrackers, weaker mixes will not work well. With magnalium and magnesium coarser than -325 mesh, or with aluminum coarser than 7 micron powder the composition will be not working correctly, will be much more weaker, or if the metal powder particle size are too coarse does not working. KClO4 based flash powders for firecrackers they work well in all sizes. However, many other things are not.

[cmjlab]

Having seen Swapnilsutar's videos of shells that are nitrate flash broken, I can certainly attest to the excellent functionality of nitrate flash!

 

As for the paper, I don't think the point is to make a flash that is the loudest possible at any expense - quite to the contrary, it looks to be an acceptable alternative firecracker which is similar to commercially available firecrackers, without violating the ban in India on regular firecrackers. Studies show the nitrate based crackers to be within 50 decibels of the commercial variants, which is pretty good based on the limitations.

 

Much to the same point for commercial firecrackers here in the U.S., they are not made of the best quality ingredients, aimed at the loudest possible variant. They were made in China, so are made with cheaply available ingredients, but "loud enough" to satisfy their intended customers in the 1980's (teens and young adults). From a cost effective, commercially viable perspective, a KCL04 and mix of cheaper bright AL (with all sorts of mesh sizes) would have been plenty loud enough for commercial sales in the U.S.

 

Your in-depth study on flash is impressive to say the least, but I don't believe it correlates to commercial processes where cost, efficiency, and now - consumer safety regulations are of more importance. I'd guess that the closest accurate formula for commercial crackers in the 1980's would be as mentioned in pyrokids post above. (Maybe Hitt's Crackas would have been made with quality ingredients, prior to the 1960'd bans / start of consumer fireworks regulations).

[mx5kevin]

Here in Europe, these firecrackers are average 120dBA@15m with 0.3g flash the stronger P1 and P2 technical versions with 0.5g flash are 135dBA@15m and 120dBA@25m. What are emitted at a sharp sound frequency. Because besides the decibel, it does not matter at what frequency the sound is emitted. It is the basis of all of these dark aluminum, magnalium, KClO4 with sulfur, or sometimes maybe KClO3 (without sulfur). Like the Fünke Special Pirat, Italian Buffalo 100pcs, Italian P1 Pirat 100pcs. It cannot be made in high quality in cigarette-sized or smaller sizes like the Mini Pirat from another way. Don't need much of these ingredients and they are cheap. These types of small cigarette sized and much more smaller than cigarette sized firecrackers with 0.1g flash which is a small amount the size of a knife tip will not work properly with nitrates or other less stronger oxidizers. They cannot use another oxidizers to these products at the factory either what are not KClO3 or KClO4 based. It is not worth experimenting with alternatives at home. Extra money, unnecessary time, and the quality won't be the same. If someone wants to make this directly, and wants to buy chemicals directly for this purpose, everything else is a waste of money and time. Shells or larger firecrackers completely different products, the fact that something is good for another product does not mean that it is also good for this product. Bright aluminum are not used for these firecrackers (the particle size is also not suitable), that light gray powder is -325mesh of finer magnalium. I have seen many such cigarette sized commercial firecrackers they all have the same basis KClO4 magnalium -325 mesh, or dark aluminum 2-7 micron and some sulfur.

[Arthur]

I've seen several stage/theatre items that use a nitrate/ sulphur/aluminium mix very successfully. For many factories every alternative to chlorate is better simply because of the avoidance of risk and incompatibilities if most products use a variant BP formulation (Gerbes etc). Total avoidance of chlorate is a great move .

[cmjlab]

if ~325 mesh Al is your main criteria for particle size, here is a bright flake Al that is -325.

 

https://www.fireworkscookbook.com/product/aluminum-bright-flake-325-mesh/#:~:text=Bright%20aluminum%20usually%20passes%20120,mesh%20size%20than%20bright%20aluminum.

 

I think we are getting off topic here though - I've never worked at a Chinese factory and have no idea what they use specifcally.

[mx5kevin]

Required metal powders for the KClO4 flash:

 

Aluminum powder 3-7 micron required. (under 8 micron -1750 mesh)

Magnesium or Magnalium -325 mesh (under 40 micron)

 

The product works properly within these parameters. Bright flake Al that is -325 mesh exceeds this limit quintuple and burns like thermite with KClO4, its density is not suitable either. This grain sized aluminum is not suitable for flash powder. As far as I know, it is not commercially available in the appropriate grain size for this purpose. And it is not good to work with it, it stains everything with that silver paint, it floats in the air.

 

I have been working with these raw materials for years. I have seen the used flash in many cigarette-sized and smaller firecrackers. The used flash can be easily established if someone works a lot with these ingredients. It clearly does not contain any bright flake Al none of them. Its texture and appearance would be spectacularly different if it were used for it.

 

I made lot of KClO4/Al/S, KClO4/MgAl/S and KClO4/Mg/S with 50/40/10% ratio. What are used the factory setup are clearly the KClO4/Al/S and KClO4/MgAl/S versions in these tiny firecrackers. When made, they are exactly the same. The differences compared with everything else where another flash powders tested are significant. Which is required from the factory: Price, easily available suitable particle sized raw materials, safety, quality, the parameters meet all criteria expected in professional production. The -325 mesh magnalium, and 3-7 micron aluminum easily available raw materials at a cheap price.

 

The KClO4 potassium perchlorate flash with sulfur quite safe, easy to handle. Potassium chlorate KClO3 are not safe for flash powder, friction sensitive, unstable in many case.

 

KClO3 VS KClO4 important differences and tests

 

 

 

 

 

 

 

[Zumber]

I've seen several stage/theatre items that use a nitrate/ sulphur/aluminium mix very successfully. For many factories every alternative to chlorate is better simply because of the avoidance of risk and incompatibilities if most products use a variant BP formulation (Gerbes etc). Total avoidance of chlorate is a great move .

Yes And I can now say that We dont have permission to use perchlorates and chlorates but we developed every colour effects with using nitrate as a oxidizer only.I have more than 25 different star effect with nitrate only.

[Zumber]

Having seen Swapnilsutar's videos of shells that are nitrate flash broken, I can certainly attest to the excellent functionality of nitrate flash!

 

As for the paper, I don't think the point is to make a flash that is the loudest possible at any expense - quite to the contrary, it looks to be an acceptable alternative firecracker which is similar to commercially available firecrackers, without violating the ban in India on regular firecrackers. Studies show the nitrate based crackers to be within 50 decibels of the commercial variants, which is pretty good based on the limitations.

 

Much to the same point for commercial firecrackers here in the U.S., they are not made of the best quality ingredients, aimed at the loudest possible variant. They were made in China, so are made with cheaply available ingredients, but "loud enough" to satisfy their intended customers in the 1980's (teens and young adults). From a cost effective, commercially viable perspective, a KCL04 and mix of cheaper bright AL (with all sorts of mesh sizes) would have been plenty loud enough for commercial sales in the U.S.

 

Your in-depth study on flash is impressive to say the least, but I don't believe it correlates to commercial processes where cost, efficiency, and now - consumer safety regulations are of more importance. I'd guess that the closest accurate formula for commercial crackers in the 1980's would be as mentioned in pyrokids post above. (Maybe Hitt's Crackas would have been made with quality ingredients, prior to the 1960'd bans / start of consumer fireworks regulations).

Yes it works grate because we have every type of superior quality of aluminium powder.

[mx5kevin]

This products are available here in Europe.

 

Performance of different aluminum powders in flash

 

Aluminum

 

Aluminum Pyro Dark Al 6-7 µm the same properties as Black 000
Aluminum Super Dark Al 4-5 µm the same properties as German Dark
There is almost no difference between the two, the 6-7 micron is cheaper.
Aluminum German Dark Al the finest available, aluminum powder which is much more costly than the previous two and not better.

 

All three are of very good quality, almost black, very dark in color and are clean to work with. The air is not full of metal dust. I would generally consider all blackhead aluminum relatively equal. Any slightly better or poorer performance will be hard to discern.

 

Magnesium and magnalium -325, -400mesh (40micron)

 

Blue Aluminum and 30 micron Aluminum (spherical mat gray dense clean to work with it) same product here the blue aluminum and 30 micron aluminum powder.

 

Aluminum Firefly Al <160μm, Aluminum Bright Al 45 μm have a light grey color can't make a flash powder from it. The air are full of metal powder particles when used, everything gets dusty. As aluminum flakes here you will get craps like this. Flake particles in 2-7 micron black aluminum are good the maximum rise rate of explosion pressure for flake aluminum powder is 4.19 times than that for large spherical aluminum powder. It's just not that product.

 

Potassium chlorate and potassium perchlorate selling have restrictions in the USA and EU too. This is itself an advertisement for this chemical for what it can do, how strong stuffs we can made it from it. In the unrestricted oxidizer category what easy to buy you cannot get anything that brings this quality. No matter how good your other raw materials are, those oxidizers are not strong enough or chemically incompatible. The difference between the two in quality is drastic.

 

From 0.3g mini polumna firecracker with much more finer tan 400 mesh homemade magnesium from boiler anode close to 20micron (The Mg coated with linseed oil and dried to it). KClO4/Mg/S 5/4/1 ratio the most reactive KClO4 flash powder. Presents it well the real power of KClO4 in small sized firecrackers. The product was made in such a way that I did not buy anything in any pyroshop. I solved everything at home the KClO4 using a homemade perchlorate cell, Mg from boiler anode and fuse too from a self made BM.

 

 

A more detailed video with a comparison is here.

 

https://odysee.com/@mx5kevin:a/How-to-make-powerful-firecracker-flash-powders-and-fine-magnesium-aluminium-powder:e

 

KNO3/Mg/S, KClO4/Al/S, KMnO4/Al/S, KClO4/Mg/S worth checking out the comparison from (aluminum foil and boiler anode based) 100% homemade metal powders.

Edited May 14, 2023 by mx5kevin

[Zumber]

https://youtube.com/shorts/y0fMP50oHHw?feature=share

Nitrate crackers garlend 1000 string.

[Richtee]

The 80’s were not a time I was much active. Well, in pyro. Cut my teeth in the 70’s, and I DO remember the bright silver flash. The Black Cats, Thunderbombs, etc had that. I remember some “ladyfingers” no brand..sorry - that were a darker flash. Little fuggers had a kick tho. Sooo. perhaps to compensate for smaller/less powder they went with the dark?

[mx5kevin]

The light gray powder is like that in these videos, it's magnalium powder with KClO4 and sulfur several ratios are used. Or dark aluminum used there the flash are darker fast and have a characteristic sulphurous smell, sometimes here with the aluminum are Sb2S3 are used. Sometime with sulfur are not characteristic the smell but an expert nose senses that it is there. If you worked with lot of firecrackers from KClO4, KClO3, Dark Al, Mg, Mg/Al, S and Sb2S3 and this is your specialty, you can tell exactly what it is when you see it. They like magnalium because it's cheap, if the metal powder are coarse -325mesh it is also reactive not required extra fine metal powder like in aluminum to get it work. It can be well filled with sulphur. Without sulfur with KClO3 also works well. You need very little of it in the firecracker from this KClO4 based flash powders and it explodes exremely noise with great light, which customers love. You can make much better flash powder with KClO4 Dark aluminum and sulfur, what are louder, brighter, the flash powder is much more faster.

 

 

 

If you watch my previous videos the flash powder with 5 KClO4 4 Mg 1 S are light gray. In my flash both with Al, Mg, MgAl when 50/40/10 ratio are used the smell of sulfur is not characteristic only expert nose senses that it is there. The point is power, light, storage stability, friction sensitivity. With magnesium will always be the fastest and most sensitive for friction. Which is always common KClO4 or KClO3 are used in this tiny firecrackers, without it, these small firecrackers are not feasible.

 

 

60% KClO4 30% Al Dark Pyro (1000 mesh) 10% Sb2S3 3g FP. In the factory, it is one of the best that is used for these commericial mini and high quality not that cheap Chinesise firecrackers and have that characteristic sulphurous smell, dark gray almost black color and the flash are fast (like the Pinto Anaconda 100 pcs whit visco fuse with 0.25g flash) (Austria and Germany) use this flash. The bang are extreme loud, the flash light are extreme white bright. But compared with a KClO4 Al S 50 40 10 nothing better.

 

 

Can compare with a homemade 0.1g KClO4 Al S 50 40 10 mini match cracker which makes a pretty big hole in the beer can, extremely bright, and have a extreme sharp strong voice what you feel on your eardrums. And it can achieve that performance with half as many flash powder.

 

 

 

 

 

 

 

[mx5kevin]

Chinese firecrackers are filled with lot of sulfur in addition to KClO4 Mg/Al, and mixed with cheaper KNO3 or Ba(NO3)2 half with KClO4 or KClO3 which is why the flash powder is slow. In the case of KClO4 and KClO3 (without sulfur), this still can explodes loudly even though the mixture is slow and a strong much more weaker oxidizer mixture are used. KClO3 and KClO4 are so strong oxidizers that they many cases can keep it retain their sharp sound when mixed in half with other, much more weaker and cheaper oxidizers. If someone puts coarse -400 mesh aluminum in it, or much more finer 30 micron pure aluminum it will not work. Aluminum powders available at the paint store will not work because they are not fine enough. If someone buys bright silver aluminum pigment it is one of the worst materials you can buy for this and it is a pain to work with. Flash powder is like thermite with it, the flash powder has no density and everything get dusty, even the electric balance inside. Anyone who wants to give such advice to use that is completely untrustworthy on the subject. It is guaranteed not to be using that the in the factory. 50:50 magnalium in a ball mill are easy way refined unlike magnesium or aluminum. The alloy can also be prepared at home much more cheaper way than buying the powder, it can even be made for more than half the price of the powder. They can dilute the flash powder much better with cheaper ingredients than in the case of aluminum.

Edited May 17, 2023 by mx5kevin

[cmjlab]

Mg/Al is cheap? I'd like to be introduced to whoever sells Mg/Al to you!

[a_bab]

Mx5kevin, don't forget the mgal- based flash doesn't store well. Especially if it contains S. The black Al flash on the other hand, used in the crackers made by that Albanian company we all know, stores perfectly and is about the strongest you can get.

[mx5kevin]

Mx5kevin, don't forget the mgal- based flash doesn't store well. Especially if it contains S. The black Al flash on the other hand, used in the crackers made by that Albanian company we all know, stores perfectly and is about the strongest you can get.

 

When the MgAl or Mg are coated with linseed oil (and dried from it to get a hard strength coating) or potassium dichromate does not have any storage stability issue in the presence of KClO4, sulfur, Ba(NO3)2, KNO3. With KClO4 i use Dark Al 3-5 or 6-7 micron and sulfur. In the book of Takeo Shimizu: The Art, Science, and Technique there is a table and a detailed description of this how to protect these metal powders and against what effects and chemicals page 121-126. For magnesium, the most important thing is the right protecting coating.