Illumination - A question of shock resistance...

[FlareLauncher]

I am wanting to learn about illumination, but specifically illumination rounds for my 37mm launchers. I DO 'roll my own',as it is the only way I can afford to shoot the launchers! Store bought rounds in the 37mm family goes from $6 - $40 per shot. I just don't haver that kind of money! But I have learned how to manufacture 37mm loads that can carry payloads - albeit SMALL payloads - fairly good distances. I can get 200 + yards in an arc, and about 75 - 100 feet vertical, which makes for a nice "firework" type display. I shoot micro stars, smokes and ninja smokes (a nice 'pop' upon opening) so far.

 

Im interested in illumination, and therein lies the problem. I'm reading and learning about flash powders, and frankly, it makes me a little nervous. I do NOT want a detonation in my launcher (one of them is aluminum) and from what I can learn, flash is sensetive. I have been wondering about coarser aluminum that would 'sparkle', and what kind of illumination I could get from that - think 35mm film can payloads - I can go more, but that is where I start.

 

I also have a "Destructive Device" criteria I must avoid, but I will take responsibility to make sure any recommendations you may make fall within the limits imposed there. IF your idea does not, I will either adjust it down or not use it. I enjoy my freedom and wanna keep it! So - any assistance is appreciated.

 

Thanks in Advance,

 

FlareLauncher

[nater]

If you are wanting to make a bright flare, flash is NOT want you want. Flash makes a report with a very brief white flash, certainly not what I would call illumination.

 

It sounds like you want to light up an area with a flare? There are illumination stars in some texts and have

traditionally been used in flares and rocket headings. They are known to be hard to light.

 

 

You mention using coarse aluminum for a "sparkle". Atomized aluminum in different mesh sizes is commonly used for glitter stars. Is that what you mean?

 

The term "destructive device" can be taken many different ways. To most of us, that means ground salutes like M-80s, however to the public and certain authorities that could mean any homemade pyro.

[FlaMtnBkr]

I would think if you want any type of 'hang time' you will want to use a parachute. From that run a piece of wire to a star or comet of flare comp.

 

There are some illuminating flare comps and a lot of them were developed by the military for war time use. I can look for some, but you can find a lot of you search rec.pyrotechnics. There isn't a lot of activity there now, but there is a wealth of knowledge there using a search.

 

Once you have a comp, you will need to figure out a parachute. You will probably want a small ejection charge that lights the star, then packing, the wire, and finally the folded parachute. Mylar emergency blankets are supposed to make great parachutes. It wants to unravel and can survive a bit of heat.

 

Good luck and let us know if you have any questions.

[Bobosan]

"destructive device" in regards to 37mm rounds would be defined by ATFE.

[FlaMtnBkr]

Oh, and flash is just going to make that destructive device you don't want. Even 2 grams, less than half a teaspoon, will be as loud or louder than a shotgun. Plus it will only illuminate for a few milliseconds. Once in a device it will survive the lift, as all flash does in commercial devices. The danger is making it and loading it in the device.

[Bobosan]

Oh, and flash is just going to make that destructive device you don't want. Even 2 grams, less than half a teaspoon, will be as loud or louder than a shotgun. Plus it will only illuminate for a few milliseconds. Once in a device it will survive the lift, as all flash does in commercial devices. The danger is making it and loading it in the device.

 

+1

 

From a post in http://www.amateurpyro.com/forums/topic/5282-definition-of-destructive-device/?hl=%2Bdestructive+%2Bdevice

 

 

"The definition of a "destructive device" is found in 26 U.S.C. § 5845(f). The definition reads as follows:

 

(1) any explosive, incendiary, or poison gas, bomb, grenade, rocket having a propellant charge of more than 4 ounces, missile having an explosive charge of more than 1/4 ounce, mine or similar device."

Edited April 22, 2014 by Bobosan

[nater]

Here is one illumination star that was recommended to me:

 

Hardt White #6

 

Barium Nitrate - 64

Aluminum American Dark #809 - 19

Potassium Nitrate - 08

Sulfur - 05

Dextrin - 06

 

There are a few comps similar to this one, just with some different ratios or binders. It is not listed, but I would add 2% boric acid to the water when you dampen this comp.

[FlareLauncher]

Yes, you all seem to be correct about the DD issue, and thats the one I MUST not violate. I can get a DD permit that allows larger payloads and 'offensive' loads, such as batons, rubber balls, etc. I have no interest in that kind of thing and carefully avoid those pitfalls. I DO have interest on 'non-report' lighting, so you are probably spot on when you say not flash. I do mean glitter which was what I was looking for when I said sparkle. My concern with parachutes is the complexity of the build, and I am limited in my payload size. Perhaps what I need to do is look at building some stars to use as comets? 3 or 4 good sized stars would provide the illumination I'm seeking without report.

 

Thank you all for your patient with my stupidity! I believe you are (patiently) herding me in the right direction. Oh - and rec.pyro may be a good place for me to search, indeed. I feel optimistic now!

[nater]

Gotcha. We once set up some night time loads for Civil War reenactors to load in their cannons. It was just bundles of different stars, but they loved the effect. Mumbles thinks it is an ugly comp, but I like to recommend D1 glitter as an easy start. It is a simple gold glitter which uses easy to find components. Another glitter that is well liked is Winokour 39J. Both have been discussed here in depth and should be easy to search for.

[Bobosan]

Yes, you all seem to be correct about the DD issue, and thats the one I MUST not violate. I can get a DD permit that allows larger payloads and 'offensive' loads, such as batons, rubber balls, etc. I have no interest in that kind of thing and carefully avoid those pitfalls. I DO have interest on 'non-report' lighting, so you are probably spot on when you say not flash. I do mean glitter which was what I was looking for when I said sparkle. My concern with parachutes is the complexity of the build, and I am limited in my payload size. Perhaps what I need to do is look at building some stars to use as comets? 3 or 4 good sized stars would provide the illumination I'm seeking without report.

 

Thank you all for your patient with my stupidity! I believe you are (patiently) herding me in the right direction. Oh - and rec.pyro may be a good place for me to search, indeed. I feel optimistic now!

 

No problem, FlareLauncher. Reloading 25mm flares got me into pyro. I knew how to drill, ream and install 209 primers into the empty metal casing but I needed a flare or smoke comp to complete them while staying within the law.

 

One pyro interest led to another, and then another, so it goes and before you know it, you are hooked on pyro.

Edited April 23, 2014 by Bobosan

[MrB]

Would this be helpful?

 

As far as i can tell it's NaNO3 / MG flash, with a binder.

B!

Edited April 24, 2014 by MrB

[FlareLauncher]

So I'm liking the 'comet' (stars) idea. A mainstay payload delivery device for my thumpers has been the 35mm film cartridge. I launch it on top of a small piece of wood dowel that is driven out the tube usually by black powder, as I see no big advantage in smokeless, and BP is more forgiving.

I'm thinking that if I make disks instead of stars, I could stack them in the canister with a small burst charge to ignite them. I also was thinking that a core would allow simultaneous lighting of the disks - think life savers. Perhaps a short piece of quick match in the hollow cores as they are stacked? Maybe I could even use a 35mm canister as a cookie cutter to make the stars?

I'm really getting excited about this project, and glad to be looking into more familiar territory. All input is welcomed.

Thanks, MrB - I'm looking at that recipe now...

[MrB]

I'm thinking that if I make disks instead of stars, I could stack them in the canister with a small burst charge to ignite them. I also was thinking that a core would allow simultaneous lighting of the disks - think life savers. Perhaps a short piece of quick match in the hollow cores as they are stacked? Maybe I could even use a 35mm canister as a cookie cutter to make the stars?

 

Thanks, MrB - I'm looking at that recipe now...

Just from reading a little while looking around, i doubt using the 35mm film canister as a cookie cutter will be the way to go. I haven't made up my mind on burning, or rather lighting the flare from the inside out. I think it's a bad idea, but i'm not sure if i can explain why, in a way that makes sense. Anyway, i'm going to try, with both points.

 

Cookie cutter idea... No. The "recipes" i linked to doesn't state it, but generally it's my understanding that the flares used for military purposes is made through packing of the compounds, with pressures equal to, or higher then most rocketpresses can deal with. The purpose seams to be to limit the speed of the burn, so that you can use as energetic materials as possible, and get a stronger light-source that lasts "longer". As i said, in essence the above link is just flash, with a fancy binder.

 

Lighting from the center... It will create a jet of burning matter that shoots out from the cavity, in both ends. As long as the pressure isn't higher then the thing can handle, it would be fine But any light generated "inside" the hole would probably be wasted. It would also create a weak lightsource to start with, and increase in strength as the hole grows (and with it, the jets)

I think this is a unit that benefits from the same kind of pasting as a crossette. Wrap it up, leaving one end exposed. Once lighted it should provide the same amount of light pretty much all the way until just before it burns out.

 

Again, working from what i've gathered from misc links, it looks like military flares are pretty much darts, with a delay that kicks out the chute, and lights the candle. You should look at hobby rockets for the design on "kick out" charges, and parachutes, but coming up with a design for the delay... Military used chemical delay fuses, the compositions might be harder to come by. But you REALLY want to make sure it's not something that might go of on it's own.

 

Weirdly.. After looking around, i sort of get a feeling these flares are high pressure made roman candles, where the casing is something to allow a more rough treatment, like hard plastics, or possibly magnesium tubes (which would help with the light...)

B!

 

Edit

Right

Forgot this link.

The designs here seam more likely to pull of on your own, then more recent designs...

If they could build them by hand for the second world war, so could you... Sadly, build instructions NOT included.

/Edit

Edited April 24, 2014 by MrB

[FlareLauncher]

Interesting line of thought, B. I was thinking in the genre of stars, yet disk shaped stars. As the canister reaches apogee, the fuse has burned thru the length of the dowel into the canister, where it then touches off the secondary charge in the can that lights the core of quick match and disperses the disks into the stratosphere (ok, maybe not that high) and lights them in the process of the burn. Maybe forming the disks in the can to be launched in? Layers of a measure of star comp with nylon spacers between, with a dowel inserted for manufacturing (to be removed later) and replaced with BP? Perhaps I could ram them with a mallet to give better compaction - no comparison to a rocket press, but the canister would not tolerate that, anyways. It would be wonderful to be able to assemble, ram, dry and launch in one can! I'm reminded that one problem with being delusional is it 'sounds good to me' right up until it doesn't work....

[Mumbles]

Those NaNO3/Mg mixtures are truly bright. They'll light up a large area, and depending on the ratio can burn relatively quickly.

 

The actual geometry and formula will depend on how you want these things to work. The most common way these are made is with parachutes. In that case the flare composition is usually compressed into a tube that burns away. They can also be fired as comets essentially where you'll have several seconds of hangtime. For this, I'd think you'd want something like a cored comet. That way you'd get the maximum burn rate and illumination.

 

A word of warning. A lot of these illumination type compositions can burn quite violently in a powdered state. You will probably want to fire a few testers out of a similar sized cardboard or HDPE mortar. Comets of these types of compositions have been known to turn into salutes and tear the gun/mortar if they break up on lift.

[MrB]

Perhaps I could ram them with a mallet to give better compaction - no comparison to a rocket press, but the canister would not tolerate that, anyways. It would be wonderful to be able to assemble, ram, dry and launch in one can!

I don't know if it's just me, but seeing you ram this stuff, would make me tear you away from your tools, and slap you around. A lot. Your not a pyro, so i wont shout at you, but ramming metal is a no-go in general, ramming flash... You should only do that if you feel you got a hole in your head, that you want to fill with the ram. Really. Press this stuff. Don't ram it. Even if magnesium shouldn't spark, it's bad practice, and considering that this is (damn, i keep repeating my self) basically flash, your going to get a nasty big old "bang!" if it ignites while ramming. As far as the canister goes.... Supports.If your still thinking 35mm film canister, Make it out of a block of metal that you split in half, bolt back together, and drill a fitting hole in the center.

 

Those NaNO3/Mg mixtures are truly bright. They'll light up a large area, and depending on the ratio can burn relatively quickly.

 

The actual geometry and formula will depend on how you want these things to work. The most common way these are made is with parachutes. In that case the flare composition is usually compressed into a tube that burns away. They can also be fired as comets essentially where you'll have several seconds of hangtime. For this, I'd think you'd want something like a cored comet. That way you'd get the maximum burn rate and illumination.

You think cored is the way to go? I agree in that it will, without any doubt, provide the fastest burn, which in it self is a good thing for light production, but i'm not so sure about the composition burning away inside the core... Does it actually provide light that has a chance at reaching "down and light the scenery" so to speak?

 

A word of warning. A lot of these illumination type compositions can burn quite violently in a powdered state. You will probably want to fire a few testers out of a similar sized cardboard or HDPE mortar. Comets of these types of compositions have been known to turn into salutes and tear the gun/mortar if they break up on lift.

Solid flash would do that to you. I keep returning to that. Sure, this is NaNO3, and not KNO3, which slows down the reaction somewhat, but it's still flash. Magnesium based flash at that. Can someone, other then me, try and explain how much, or rather, how little you need to provoke this stuff, before it bites back, and takes a hand, or a head of in s single swipe. He seams levelheaded, and reads the stuff, but the last thing anyone needs is "mortar enthusiast blew his head clean of after visiting firework & explosives sites" as a headline in some local newspaper. Yes, i admit, i don't care half as much about the fella him self, there is only one cure for stupid, but it's sort of counter productive for the hobby. (FlareLauncher, just to clarify, i'm not calling you stupid. You would be, if you got your self killed. Thats what i'm saying. Listen to Mumbles, he's one of the good guys. I'm just a hobby pyro. All i want is for you to get this project to work, safely, and then shoot a video and show us how it turned out.)

B!

[Bobosan]

FlareLauncher,

 

There are a lot of good threads on APC for parachute flares. One example is here.

 

Use the search function and type in "parachute flare". You should have room enough in a 37 or 40mm flare to do this or at least a large time fused comet.

[FlareLauncher]

I am dumbfounded - honestly. As I read this thread, I cannot help but think 3 things;

1. What a great bunch of people here, to give and give of their formidable experience and save me not only R&D efforts, but most likely injuries as well!

2. How much would such a group consultation cost 'real world'. It seems priceless!

3. I'm having to reread this thread EVERY time I check posts because ya'll think as fast (faster?) as I do! Sheesh!

I'm just loving all these ideas and excellent input. When I 'like' your post, it is not reflexive - I really do like them! I work an obscene rotation schedule, and my days off start TODAY! I'm so looking forward to trying some of these ideas out 'real time'. Thank you, Thank you, Thank you! Please, add whatever occurs to you in this vein. I promise I shall reread this thread again before I mix or grind any chemicals pertinent to this effort. Oh - and Thank you!

[FlaMtnBkr]

If you are getting good height, and depending on how long you want the flare to last, you might be able to get away with some type of streamer to add drag and slow the fall. But if going to that work you might as well add a parachute.

 

I really don't think it will be as hard as it sounds. And I think of you want any kind of decent burn time you will be disappointed without one. It doesn't take something very long to fall a couple hundred feet. And if you have ever shot model rockets, the parachute doesn't add much complexity.

 

Also, finely divided magnesium can be some touchy stuff. Safety is always number one so I would advise working outside and wearing appropriate clothing. All cotton, some heavy gloves wouldn't be terrible, and have a bucket of sand and water close by. Also, pay attention to any different smells and if anything seems to be heating up. Magnesium burns so hot that it actually splits water into hydrogen and oxygen and flame up a mag fire. That is what the bucket of sand is for. It's better to have stuff at hand and not need it, than to need it and not have it.

 

Good luck, and if you find any formulas you are curious about or have any questions, feel free to ask.

[FlareLauncher]

If you are getting good height, and depending on how long you want the flare to last, you might be able to get away with some type of streamer to add drag and slow the fall. But if going to that work you might as well add a parachute.

 

I really don't think it will be as hard as it sounds. And I think of you want any kind of decent burn time you will be disappointed without one. It doesn't take something very long to fall a couple hundred feet. And if you have ever shot model rockets, the parachute doesn't add much complexity.

 

I believe you, and have decided after several good counsels that parachute is the way to go.

 

Also, finely divided magnesium can be some touchy stuff. Safety is always number one so I would advise working outside and wearing appropriate clothing. All cotton, some heavy gloves wouldn't be terrible, and have a bucket of sand and water close by. Also, pay attention to any different smells and if anything seems to be heating up. Magnesium burns so hot that it actually splits water into hydrogen and oxygen and flame up a mag fire. That is what the bucket of sand is for. It's better to have stuff at hand and not need it, than to need it and not have it.

 

​I have been doing a lot of 'back reading' in the forums and decided it is smart to learn from Dags' misfortunes. When I decide what chemicals to combine, I'll damned sure take appropriate precautions. By the way, I am a Haz - Mat specialist in real life (how I make my $ ) and I understand the necessity for caution. That said, If you think I might be missing something, EVERYONE, please let me know. My ego is not as important as my safety - or life!

 

Good luck, and if you find any formulas you are curious about or have any questions, feel free to ask.

 

You can bet the farm on that,FlaMtnBkr! Thanks again...