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Really slow photoflash

Pyroitaly

By Pyroitaly
in Pyrotechnics

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Pyroitaly Newbie

Pyroitaly

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Hi pyros,

I was thinking there Is a composition named slow photoflash which consist of:

-potassium perchlorate 18

-barium nitrate. 10

-magnesium fine. 36

-shellac. 36

 

What do you think about this composition? There Is a composition with magnesium and magnalium with only 14%of oxydizer which makes a big flash.. i would like photoflash as long as possible...Someone have tryed this composition??

Richtee Community Regular

Richtee

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There’s this stuff listed-

 

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Pyroitaly Newbie

Pyroitaly

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Yes, Someone have a video or has tried this composition? Edited by Pyroitaly
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Arthur Community Regular

Arthur

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Slow photo or illuminating flashes are often under oxidised and rely on the little oxidiser present spreading the mix which can then burn in the air.

Richtee Community Regular

Richtee

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As you can, or SHOULD see, perchlorate is not used, but chlorate.

 

No, I have not tried it. I have no application for it.

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Pyroitaly Newbie

Pyroitaly

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Sorry, i have made a transcription error..Why cant perchlorate be used instead of potassium chlorate?
h0lx Newbie

h0lx

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In my series of experiments which I would best entitle as "What else can magnesium reduce?", a lot of the ones, when overfuelled produced an absurdly bright and long lasting fireball due to vapourised Mg burning in air. 1:1 plaster of paris:Mg powder comes to mind(however it produces quite orange illumination). 1:1 SrCO3:Mg produced a red one as expected, however didnt have that much power, adding 10% perchlorate helped it along.

Basically have a sulfate/carbonate/other slowish oxidiser and magnesium in a fuel rich ratio and voila.

Pyroitaly Newbie

Pyroitaly

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In my series of experiments which I would best entitle as "What else can magnesium reduce?", a lot of the ones, when overfuelled produced an absurdly bright and long lasting fireball due to vapourised Mg burning in air. 1:1 plaster of paris:Mg powder comes to mind(however it produces quite orange illumination). 1:1 SrCO3:Mg produced a red one as expected, however didnt have that much power, adding 10% perchlorate helped it along.

 

Basically have a sulfate/carbonate/other slowish oxidiser and magnesium in a fuel rich ratio and voila.

Thank you!

  • 1 month later...
Pyroitaly Newbie

Pyroitaly

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Hi pyros,

There is a very strange pyro alluminium which Can be used for really slow photoflash but i dont know so much about this fine flitter allumium called pyro uz..Does someone has any idea about the composition for slow photoflash with this alluminium?

FlaMtnBkr Rookie

FlaMtnBkr

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What is your application? Taking pictures? Illuminating an area? On the ground or in the sky? How long would you like the illumination to last?

 

Similar amounts of metal will produce similar "amounts of light". So a device that burns in a fraction of a second will make a very intense and bright light in a short time while if it's spread over a few seconds it will be less intense and if spread over a fairly long time can be quite dim. That is likely obvious but if you're limited by size and need a certain brightness then the burn time will need to be adjusted. Again, that's probably obvious but if we know what you're trying to achieve and any limitations it may get you a better answer.

 

You may also think about flares that get some of the delay from compaction of the composition and/or the binder used, as opposed to a really slow burning formula that you may start having problems keeping it lit.

 

There are military formulas going all the way back to the world wars where essentially a photo flash bomb was dropped to illuminate a very large area and take surveillance photos. As well as groups of flares attached to parachutes to give more time to take the pictures. Some of these are well tested and documented and can be found for free if you know where to look.

 

You will always get better answers if you can include as much info as possible about what you're trying to accomplish and any restrictions that you might have...

Pyroitaly Newbie

Pyroitaly

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I would like to find a composition for use in the air in a shell and that it last about 3-4 secondspossible with this type of alluminium. The question is : what fuel oxidizer ratio should be used?Thank you
Pyroitaly Newbie

Pyroitaly

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I know a lot of photoflash composition but none with this type of alluminium
Pyroitaly Newbie

Pyroitaly

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Do you have any idea please?
cmjlab Rising Star

cmjlab

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It looks like pyro uz aluminum is just a coarse Atomized aluminum "commonly used in sparklers and other pyro devices" (according to their website). A picatinny arsenal researched photoflash comp, is in the attached screenshot, using Barium Nitrate, Potassium Perchlorate and Atomized Aluminum. I imagine you'd have to research the rest on your own, as 3-4 seconds of a "flash" of light seems like an incredibly long burn for any "flash". **Ive not made or tested any photoflash**

 

Good Luck!

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Richtee Community Regular

Richtee

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I would like to find a composition for use in the air in a shell and that it last about 3-4 secondspossible with this type of alluminium. The question is : what fuel oxidizer ratio should be used?Thank you

Something THAT long... maybe you are looking for a “star” or a disc of material. Not a powder.

Pyroitaly Newbie

Pyroitaly

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No.I have a video of similar composition with weak shell break. Edited by Pyroitaly
mabuse00 Rookie

mabuse00

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I would like to find a composition for use in the air in a shell and that it last about 3-4 secondspossible with this type of alluminium

As Richtee wrote, this is only possible with pressed/bound composition.

A cloud of maybe 6mm - depending on the burn rate of course - microstars should do the job.

This could be achieved with better performance (->more light output per mass of composition) if MgAl or Mg is used.

 

 

There are military formulas going all the way back to the world wars where essentially a photo flash bomb was dropped to illuminate a very large area and take surveillance photos. As well as groups of flares attached to parachutes to give more time to take the pictures. Some of these are well tested and documented and can be found for free if you know where to look.

imho the flash bomb gives only one very short flash, so that in the darkness the the flash duration works like the shutter time...

cmjlab Rising Star

cmjlab

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As I am currently in the military and have used illumination rounds fired as a 40mm projectile, I do know that those particular illuminations are created by a flare composition slowed by a parachute, and do last up to 15-20 sec (give or take). I'd imagine that one could achieve a similar 3-4 second illumination as alluded to above by a bound / compressed flare composition or brilliant white star comp.

 

Hope that helps some.

Charles

Pyroitaly Newbie

Pyroitaly

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Thank you!!Yes like commercial illuminating parachute rockets which have 100000 cd power ca.. Edited by Pyroitaly
cmjlab Rising Star

cmjlab

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Looking more into it, Alexander Hardt's "Pyrotechnics" has a whole section on Illuminating Flares, and a rather large subsection on production of White Light. In it he specs Sodium Nitrate as the ideal oxidizer, and magnesium as the ideal fuel due to the lack of sintering and unreacted particles near the main reaction, which leads to smoke. The binder he specifies is "Laminac" (described as a class of alkyd resin and contain copolymerizing styrene monomers). I believe it's mainly referring to a cold cure resin.

 

Reference: Flares and Illuminating Lights Chapter, specifically White Light - pg. 287, provides formulas for several flare comps on 296.

Richtee Community Regular

Richtee

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The binder he specifies is "Laminac" (described as a class of alkyd resin and contain copolymerizing styrene monomers). I believe it's mainly referring to a cold cure resin.

 

I made a post a few years back on “Gorilla Glue” risers. A cold cure resin type glue and perchlorate/metal/coloring agent. Painted onto a shell...it’s spectacularly bright on the rise...

cmjlab Rising Star

cmjlab

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You've mentioned Gorilla Glue or glue of some type for a few uses haven you? I.e. fuse made with glue as a binder.... How well did the glue work as a binder? Did it interfere with burning at all?

 

Charles

Richtee Community Regular

Richtee

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You've mentioned Gorilla Glue or glue of some type for a few uses haven you? I.e. fuse made with glue as a binder.... How well did the glue work as a binder? Did it interfere with burning at all?

 

Charles

I have made some quickmatch with it. I found making a slurry with dextrin and “painting” it on paper to be better.

 

hmm.. https://www.amateurpyro.com/forums/topic/3029-a-tip/?hl=%2Bpoly+%2Brisers

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