Hello to everyone!

[Pyrogeezer]

Hello Everybody!

   I’m new to the Forum and would like to introduce myself. They refer to me as Doc. I have been in Pyrotechnics for 57 years and have loved every minute of it. I am a retired Chemical/Professional Engineer by trade and have spent most of my professional career working for and consulting with many of the major US fireworks manufacturing companies. I have made practically every type of Italian “B” stile fireworks (that were all handmade) up until about 2015, when I was forced to retire due to a back injury. This didn’t stop me from working in my machine shop fabricating pyrotechnic machines and things. My contribution to the pyrotechnics industry is that I have built more than 25 commercial Visco fuse machines that most of which are being used today here in the U.S. to produce American Visco fuse.

     I have been following the APC Forum for quite a while now and decided to sign up. Please bear with me I'm not very computer savvy, I hope I'm doing this correctly!!! 

     You probably wonder why a 76 year old Pyro Geezer would join the Forum, well, I think it’s the best site online to learn from and see what the new generation is doing, and everyone is extremely nice. There is a tremendous amount of new developments in the business and am happy to see so many young people interested in the science and art.

     I’m looking forward to learning from you guys and help in reference to old school stuff if I can.

[PyroGb]

Hi I’m also new to this forum but I have a chemicals question. I live in alaska and I am at the point of graduating potacium nitrate and sulfer but I’m haveing trouble with getting stuff up here any advice? Thanks=)

 

[Pyrogeezer]

Hi PYROGB: Both Potassium Nitrate and Sulfur are very common chemicals used in fertilizer blends. The nitrate is used as a source of nitrate nitrogen and sulfur is a micronutrient and also used as a soil acidifier. I would search around in your garden centers and find one that carries these materials. Also look in some of your large (Box stores) for Potassium Nitrate Stump remover. Make sure its 100% Kno3. I know of a few large Pyro chemical suppliers that we purchase from, but they only sell in large quantity (200 to 500 pound drums). Kind of a lot to purchase if your a hobbyist!

Good luck!

[PyroGb]

Yes so it was prety easy to get sulfer and kno3 I picked up at lowes 10$ a pound but I’m at a point where I’m needing things like strontium and better oxidizers.

[Pyrogeezer]

No problem, Go online and look up Skylighter, Pyro Chemical Source or Hobby Chemical Supply. These are just 3 of several and they carry most everything you need. Don't die from sticker shock! 

[PyroGb]

Will they ship to alaska? If so awesome thanks

[Pyrogeezer]

I know people from Europe and South America that have gotten materials from one of them, I don't remember which, but I really don"t see a problem. Just contact one of them and see what they say. I have gotten materials from Europe with no questions asked but that was a few years ago.  

[PyroGb]

Ok I’ll talk to them thanks for the info 😄

[Zumber]

9 hours ago, Pyrogeezer said:

Hello Everybody!

   I’m new to the Forum and would like to introduce myself. They refer to me as Doc. I have been in Pyrotechnics for 57 years and have loved every minute of it. I am a retired Chemical/Professional Engineer by trade and have spent most of my professional career working for and consulting with many of the major US fireworks manufacturing companies. I have made practically every type of Italian “B” stile fireworks (that were all handmade) up until about 2015, when I was forced to retire due to a back injury. This didn’t stop me from working in my machine shop fabricating pyrotechnic machines and things. My contribution to the pyrotechnics industry is that I have built more than 25 commercial Visco fuse machines that most of which are being used today here in the U.S. to produce American Visco fuse.

     I have been following the APC Forum for quite a while now and decided to sign up. Please bear with me I'm not very computer savvy, I hope I'm doing this correctly!!! 

     You probably wonder why a 76 year old Pyro Geezer would join the Forum, well, I think it’s the best site online to learn from and see what the new generation is doing, and everyone is extremely nice. There is a tremendous amount of new developments in the business and am happy to see so many young people interested in the science and art.

     I’m looking forward to learning from you guys and help in reference to old school stuff if I can.

Welcome and glad to here you.Your huge experience and Knowledge will certainly helpfull to all of us.

Thank you for Joining...☺️

[AustralianPyromaniac]

What an interesting background! And very useful for all our questions.  Did you consult on the construction of pyrotechnic devices? Formula development? Safety? 

Welcome, and Happy New Year from the other side of the world. As a chemical engineering student, it's interesting to hear from someone at the other end of the career path. I sent you a private message, which you'll find in your mailbox on the top right of the home screen. Should have a little red 1 next to it. 

P.S. Can you go read this and answer if you have any input  

 

[cmjlab]

Welcome to the forums, you have a pretty impressive background, and even more impressive willingness to share your knowledge with hobbyists like myself, it says a lot! I look forward to picking your brain on Italian style shells, as those (and Maltese) shells have been my mainstay since I took an interest in Pyro, I can watch Beraq shell videos all day if I'm not careful..... 😀.  

Whereabouts in New York are you from?  I grew up in WAY northern NY myself.

Charles

[Zumber]

1 hour ago, AustralianPyromaniac said:

What an interesting background! And very useful for all our questions.  Did you consult on the construction of pyrotechnic devices? Formula development? Safety? 

Welcome, and Happy New Year from the other side of the world. As a chemical engineering student, it's interesting to hear from someone at the other end of the career path. I sent you a private message, which you'll find in your mailbox on the top right of the home screen. Should have a little red 1 next to it. 

P.S. Can you go read this and answer if you have any input  

 

I have not that deeply studied crackling mixture but here is discussion from another forum might helpful to you.

[Pyrogeezer]

13 hours ago, Zumber said:

Welcome and glad to here you.Your huge experience and Knowledge will certainly helpfull to all of us.

Thank you for Joining...☺️

Thank you Zumber! Glad to be aboard. I hope I can answer some questions about technology and old school stuff. 

[Pyrogeezer]

12 hours ago, AustralianPyromaniac said:

What an interesting background! And very useful for all our questions.  Did you consult on the construction of pyrotechnic devices? Formula development? Safety? 

Welcome, and Happy New Year from the other side of the world. As a chemical engineering student, it's interesting to hear from someone at the other end of the career path. I sent you a private message, which you'll find in your mailbox on the top right of the home screen. Should have a little red 1 next to it. 

P.S. Can you go read this and answer if you have any input  

 

Hi AustralianPyromaniac: Good to hear from you. That's a very good question! It does get into a bit of chemistry but instead of me reinventing the wheel, (Zumber) an APC member posted a excellent explanation from the all time great "Dr. Shimizu" on the subject. Check it out, I think you will find it interesting. 

[Pyrogeezer]

12 hours ago, cmjlab said:

Welcome to the forums, you have a pretty impressive background, and even more impressive willingness to share your knowledge with hobbyists like myself, it says a lot! I look forward to picking your brain on Italian style shells, as those (and Maltese) shells have been my mainstay since I took an interest in Pyro, I can watch Beraq shell videos all day if I'm not careful..... 😀.  

Whereabouts in New York are you from?  I grew up in WAY northern NY myself.

Charles

Hi Cmjlab; Thanks for the welcome. I started in the pyrotechnics field in 1964 when I was a mear 16 years old. I was lucky enough to live close to fireworks company in North Bergen N.J. I befriender the owners and over the years I became part owner in the firm. It was and still an Italian family that owned the company and that's all they made was Italian type fireworks. That was about 59 years ago. 

The main reason I joined the forum is because, of the great people in the group and unfortunately there aren't very many of us old timers left! If I can, I want to pass on what I have learned and developed over the years including the era prior to the Child Protection Act of 1966. It was a great time in the fireworks business!

I live in the White Plains area of lower Westchester County NY. 

Walter 

[AustralianPyromaniac]

23 hours ago, Zumber said:

I have not that deeply studied crackling mixture but here is discussion from another forum might helpful to you.

13 hours ago, Pyrogeezer said:

Hi AustralianPyromaniac: Good to hear from you. That's a very good question! It does get into a bit of chemistry but instead of me reinventing the wheel, (Zumber) an APC member posted a excellent explanation from the all time great "Dr. Shimizu" on the subject. Check it out, I think you will find it interesting. 

Thanks for this :). I haven't seen that post. I have seen the article quoted. Do you or anyone else have access to the full article? The Pyrotechnica magazines are completely unobtainable here in Australia. 

It's hard to question Shimizu of course, but that explanation just seems so weak without supporting evidence. A 1500C flame temp is higher than I would expect to occur in the given reaction conditions. The boiling point of lead (I) oxide is much more similar to other nonfunctional oxides than its melting point is to other oxides, indicating the latter to be more likely the important factor. NC lacquer is now known to be non-critical. And there is no mention of why other metal oxides do not work. I do not believe bismuth oxide was known about at the time, but other less exotic options must have been tried.

One set of modern formulas contain CuO (B.P. 2000c) MgAl, Al, Phenolic and PVB at 2.5%. These formulas function very well, but stop working when the PVB is removed! Crazy stuff, and clearly operating by a different mechanism to that proposed. 

I'll find a full copy of that article, and go from there. But I really think there is at least more to the explanation than is given there. 

Sorry to hijack your intro post.

Edited January 2 by AustralianPyromaniac

[Pyrogeezer]

47 minutes ago, AustralianPyromaniac said:

Thanks for this :). I haven't seen that post. I have seen the article quoted. Do you or anyone else have access to the full article? The Pyrotechnica magazines are completely unobtainable here in Australia. 

It's hard to question Shimizu of course, but that explanation just seems so weak without supporting evidence. From what I understand, Al alone does not work contrary to that post. A 1500C flame temp is higher than I would expect to occur in the given reaction conditions. The boiling point of lead (I) oxide is much more similar to other nonfunctional oxides than its melting point is to other oxides, indicating the latter to be more likely the important factor. NC lacquer is now known to be non-critical. And there is no mention of why other metal oxides do not work. I do not believe bismuth oxide was known about at the time, but other less exotic options must have been tried.

One set of modern formulas contain CuO (B.P. 2000c) MgAl, Al, Phenolic and PVB at 2.5%. These formulas function very well, but stop working when the PVB is removed! Crazy stuff, and clearly operating by a different mechanism to that proposed. 

I'll find a full copy of that article, and go from there. But I really think there is at least more to the explanation than is given there. 

Sorry to hijack your intro post.

No problem at all. I have never delved to deeply into the function of dragons egg chemistry but it is an oddity in fireworks. It looks pretty obvious that Bi-Pb are fairly unique in the ability to develop this effect. They fall right next to each other on the the P. table under basic metals. and thir at.wt. is very close. I would think there are other metal compounds that could produce a similar effect but would need some R&D to really establish the fact. Years ago we made what was called (electric spreader stars) made from Zn, Kclo3, C, k2cr2o7 and a binder, usually dextrin, an old Weingart formula. They worked very well but didn't have the brilliance of dragons eggs. 

 

[AustralianPyromaniac]

The first video below shows an effect demonstrated by Neighborj https://www.amateurpyro.com/forums/profile/20510-neighborj/; crackle with just CuO and MgAl 66 parts to 33 parts respectively. The effect is pretty likely just a simple thermite, and an energetic one due to the relative weakness of the Cu-O bond, compared to, for example, Fe2O3. The energy is liberated quickly enough to generate an "explosion", rather than just burning as is the case with regular thermite. In saying that, the reaction taking place is unlikely to be a detonation, just burning fast enough to blow the micro star to pieces, which in turn creates a bang. The powder unconfined does not crackle or explode. There is a good paper as well on this subject, which investigated the CuO only crackle phenomenon. They found the explosive transition occurs at 1200-1400K and that the small delay was probably caused by the melting of the Al at 1000K "A Thermal Study of a Simple Al-CuO Pyrotechnic Crackle Composition" (Richard Harrison, 2019). They largely dismissed Shimizu's explanation of the phenomenon, citing the low temperature of the explosive transition, and saying his explanation was influenced by his earlier work on strobe comps. 

Regarding the comment on Bi and Pb being similar, I'd expect more similarities between PbO and SnO2 (M.P. 1630 C), directly above it periodically, yet tin doesn't work, which I'd blame on the higher melting point. 

Notice the near complete lack of delay in the CuO only formula. Compare this to the true crackle demonstrated in the second video by Ned Gorski, which shows a marked delay/ smolder between ignition and explosion. The Shimuzi explanation surely cannot explain the reaction between CuO and MgAl, the explosion occurs before the CuO comes anywhere near boiling (B.P. 2000 C). 

That electric spreader star looks cool, do you have a formula? Is it adapted from Weingart? Or in his book? 

 

 

 

[Pyrogeezer]

23 hours ago, AustralianPyromaniac said:

What an interesting background! And very useful for all our questions.  Did you consult on the construction of pyrotechnic devices? Formula development? Safety? 

Welcome, and Happy New Year from the other side of the world. As a chemical engineering student, it's interesting to hear from someone at the other end of the career path. I sent you a private message, which you'll find in your mailbox on the top right of the home screen. Should have a little red 1 next to it. 

P.S. Can you go read this and answer if you have any input  

 

The Weingart formula we used was directly from his book. It's not a very forgiving formula and needs to be followed fairly closely. Give the stars plenty of time to dry. Its a simple but very well performing formula. One last thing, the zinc needs to be as fine as possible. Similar to zinc/sulfur rocket fuel. 

I have done some consulting on canister shell construction, but this was many years ago before the internet existed. Today there is a plethora of informative sites available on Italian style can. shells available. My speciality was and still is the manufacture of 3/32" 1/8" and larger American Visco type Fuse, and the machines used to produce it. Also the production of (Fuse Dope) or as they call it today Nitrocellulose lacquer used in coating the Visco. 

[Zumber]

1 hour ago, AustralianPyromaniac said:

The first video below shows an effect demonstrated by Neighborj https://www.amateurpyro.com/forums/profile/20510-neighborj/; crackle with just CuO and MgAl 66 parts to 33 parts respectively. The effect is pretty likely just a simple thermite, and an energetic one due to the relative weakness of the Cu-O bond, compared to, for example, Fe2O3. The energy is liberated quickly enough to generate an "explosion", rather than just burning as is the case with regular thermite. In saying that, the reaction taking place is unlikely to be a detonation, just burning fast enough to blow the micro star to pieces, which in turn creates a bang. The powder unconfined does not crackle or explode. There is a good paper as well on this subject, which investigated the CuO only crackle phenomenon. They found the explosive transition occurs at 1200-1400K and that the small delay was probably caused by the melting of the Al at 1000K "A Thermal Study of a Simple Al-CuO Pyrotechnic Crackle Composition" (Richard Harrison, 2019). They largely dismissed Shimizu's explanation of the phenomenon, citing the low temperature of the explosive transition, and saying his explanation was influenced by his earlier work on strobe comps. 

Regarding the comment on Bi and Pb being similar, I'd expect more similarities between PbO and SnO2 (M.P. 1630 C), directly above it periodically, yet tin doesn't work, which I'd blame on the higher melting point. 

Notice the near complete lack of delay in the CuO only formula. Compare this to the true crackle demonstrated in the second video by Ned Gorski, which shows a marked delay/ smolder between ignition and explosion. The Shimuzi explanation surely cannot explain the reaction between CuO and MgAl, the explosion occurs before the CuO comes anywhere near boiling (B.P. 2000 C). 

That electric spreader star looks cool, do you have a formula? Is it adapted from Weingart? Or in his book? 

 

 

 

Cuo and MgAl can produce crackling effect but this is only just not sufficient.

Crackling effect is mostly rely on thermodynamic principles ,the composition can achieve the sounding effect based on the thermodynamic adjusting effect of the accelerator.

And accelerator is lead tetra oxide, or bismuth based....the role of accelerator is important to function stars well both in sky and ground.

[AustralianPyromaniac]

1 hour ago, Zumber said:

Cuo and MgAl can produce crackling effect but this is only just not sufficient.

Crackling effect is mostly rely on thermodynamic principles ,the composition can achieve the sounding effect based on the thermodynamic adjusting effect of the accelerator.

And accelerator is lead tetra oxide, or bismuth based....the role of accelerator is important to function stars well both in sky and ground.

Can you provide something to back that up? Or a deeper explanation of the mechanism? I have not read that anywhere. 

What does "thermodynamic adjusting effect" mean? 

There is now commercial Chinese crackle that shows only Cu and Al when analyzed by X-ray spec. It is sufficient for commercial use. They use it. But not for ground effects, it isn't as loud. But for star cores it is sufficient.