Safety of Flash in Plastic casings?

[AldoSPyro]

Hey APC forum,

 

I'm currently working on making some traditional italian canister shells, but i feel like using hand rolled paper casings for salutes is kind of a waste. I'm a beginner in pyrotechnics (I'm not a kewl boomer), but I have gathered a lot of knowledge on flash safety from Bill Ofca's documents and this forum, but I am still pretty scared of flash (maybe rightfully so) but I still want to make a few salute shells just to test out. I was thinking of using some Plastic 2" cans and mix the flash inside them using the Binary method, but I was wondering if the plastic cans could cause some static problems. But I've seen that a lot of European companies use Plastic casings for salutes.

 

Any advice would be helpful!

 

(FYI, I'm not really planning on making any salutes anytime soon because I still need to get good at making color shells first)

[MrB]

While the plastic parts are stuck together, there wont be anything for a static charge to jump to. Your good. However, i'm not sure how your figuring hand-rolled paper casings to be a waste. They are next to free to make, unlike the plastics, that aren't exactly free. On a personal note i don't like dumping plastics everywhere. There supposedly used to be someone making these from biodegradable plastics, starch i believe, but i've never seen those, and supposedly they are no longer available. I'm just guessing, but since thats a "more expensive" plastic, it might have been a price / sales issue.

B!

[Nessalco]

Aldo,

 

I was in the same boat, until I learned about flash powder made with TPA. It tames the beast quite nicely, and still is an effective report composition. It doesn't have the same light output as traditional flash, but gives a sharper report. It is easy to handle, and costs a bit less to boot.

 

I would, personally, discourage the use of plastic cases as well. It's so easy to roll up a paper case, the plastic seems a waste. So far as the rolled core bottom shots, remember that the salute casing also serves as former for the rest of the shell, plus takes the full force of the lift charge. It needs to be strongly made and solidly filled - you can't really binary mix in that situation.

 

Kevin O

[ddewees]

If the salute is large enough (60+ grams), you can use blue aluminum instead, which seems to make a lot of people feel safer.

[MrB]

It needs to be strongly made and solidly filled - you can't really binary mix in that situation.

I'm actually not sure this is true. The flash in bottomshots isn't compacted enough to be a structural part. In fact, i'm willing to bet (Not that there is any safe way to find out, and even then, you'll have a hard time finding me, and getting your money, should you win ;-) that after all the handling, when you launch it, it's no longer "full to the brim". Which pretty much means you could leave it empty as far as structure of the shell goes. The rather massive shell casing walls is what keeps it all together.

 

Also, i'm not sure i think TPA flash is safer when handling. If anything i think it's a bit like "blue" aluminum. It might take a little more to set it of, but if it goes, your still dead.

B!

[schroedinger]

Why not just insert an inner liner of about 4 turns of posterboard. This way you could easly add an end disc without filling the case to the rim.

 

Also the commercial ones i now, which aren't made from plastic, are either ball shells or made from thich paper tubes (about 3-5 mm wall), with glued in end discs and an additional thick hot glue plug.

[Maserface]

I'm actually not sure this is true. The flash in bottomshots isn't compacted enough to be a structural part. In fact, i'm willing to bet (Not that there is any safe way to find out, and even then, you'll have a hard time finding me, and getting your money, should you win ;-) that after all the handling, when you launch it, it's no longer "full to the brim". Which pretty much means you could leave it empty as far as structure of the shell goes. The rather massive shell casing walls is what keeps it all together.

 

Also, i'm not sure i think TPA flash is safer when handling. If anything i think it's a bit like "blue" aluminum. It might take a little more to set it of, but if it goes, your still dead.

B!

 

the flash its self wont do much good for structure, this is why either a heavy walled paper core is used- In the case that correctly sized cores cant be found, bottom shots "cores" can be rolled- Its all outlined in Fulcanelli.

 

If TPA flash goes off, you might be burned, but not dead- It burns like wet shit. I cant speak for BA-flash though, as I have never used it.

[AldoSPyro]

While the plastic parts are stuck together, there wont be anything for a static charge to jump to. Your good. However, i'm not sure how your figuring hand-rolled paper casings to be a waste. They are next to free to make, unlike the plastics, that aren't exactly free. On a personal note i don't like dumping plastics everywhere. There supposedly used to be someone making these from biodegradable plastics, starch i believe, but i've never seen those, and supposedly they are no longer available. I'm just guessing, but since thats a "more expensive" plastic, it might have been a price / sales issue.

B!

Thanks! I meant "waste" of time, because rolling thick shell casings and working with the end discs and all seems a lot of work for just a boom. But usually I wouldn't use plastic for a color shell, because I am trying to get good at making traditional Italo-American shells.

[MrB]

I meant "waste" of time,

Your not going to save a lot of time using plastic casings. You still need to make them the structural part of the shell, if your using them for bottom shots.

To each his own, i guess.

B!

[Mumbles]

From a lot of these replies, I have to assume that very few of you have actually ever made bottom shots. In hand rolled bottom shots, the flash does provide structural integrity. It is filled to the brim, and then settled, and repeated until solidly filled to the brim. This certainly eliminates the possibility of binary. I do the same filling and settling for hard walled cases anyway. I prefer my bottom shots and salutes to be safer by virtue of being totally solid. It has the added bonus of containing about 3x as much flash.

 

Bottom shots are integral parts of cylinder shell construction. You might as well get comfortable mixing flash it you intend to get into bigger or more complex shells.

[MrB]

In hand rolled bottom shots, the flash does provide structural integrity. It is filled to the brim, and then settled, and repeated until solidly filled to the brim.

Yeah, i guess we just wont agree on this. Unless your flash powder is pressed to a solid puck, it's not going to be a structural part of the shell. When your hand rolling them, i bet you can just leave one empty, it launches just as well, the book is there to give it it's structure. Now, i wont suggest leaving it empty, that would be a wasted opportunity for a bottom shot. But after you have filled the darn thing, if you can still use a wooden dowel and compact the stuff, then it's going to settle more when handled.

B!

[WonderBoy]

To add to what Mums said, hand rolled bottom shots also have an inner bag of kraft which is tongue folded closed on the bottom after filling, and any airspace created by that fold is filled with sawdust. This keeps the flash settled, solid, and "filled to the brim". If I am shooting a multibreak, I feel much better having that solid filling of flash vs simply relying on the chipboard disks to withstand the forces on their own. In a one off salute though, I am sure the "book" provides more than enough structure.

 

I too recommend TPA flash. When unconfined, it will still ignite and could burn you pretty badly, but at least it won't blow you to bits. It also works in small quantities, I have used it in 3/4" report inserts.

 

We did a test at a club shoot this fall, lit one pound of TPA flash in an open tub, to simulate what it would be like if it were to ignite while we were working with it. I have a picture of the set-up if you'd like, it is pretty simple.

 

http://youtu.be/WY8Py40hlYc

 

If you lit a pound of 7:3:1 like that, there would be a big ole crater in the ground. And this test used a QM leader to light it, so there was a lot of fire going in there, much more than say, a static spark or something of that nature.

 

Aldo, sorry got a little side tracked there. Are you in the US? If so, it is relatively easy to find paper tubes that you can use for small salutes, so you wouldn't have to be hand rolling all of your casings. As far as traditional cylinders go, when you get some practice, rolling the casing and using end disks takes very little time.

 

 

WB

[AldoSPyro]

Your not going to save a lot of time using plastic casings. You still need to make them the structural part of the shell, if your using them for bottom shots.

To each his own, i guess.

 

FYI I'm not making bottom shots right now, Im talking about single break salutes

[AldoSPyro]

To add to what Mums said, hand rolled bottom shots also have an inner bag of kraft which is tongue folded closed on the bottom after filling, and any airspace created by that fold is filled with sawdust. This keeps the flash settled, solid, and "filled to the brim". If I am shooting a multibreak, I feel much better having that solid filling of flash vs simply relying on the chipboard disks to withstand the forces on their own. In a one off salute though, I am sure the "book" provides more than enough structure.

 

I too recommend TPA flash. When unconfined, it will still ignite and could burn you pretty badly, but at least it won't blow you to bits. It also works in small quantities, I have used it in 3/4" report inserts.

 

We did a test at a club shoot this fall, lit one pound of TPA flash in an open tub, to simulate what it would be like if it were to ignite while we were working with it. I have a picture of the set-up if you'd like, it is pretty simple.

 

http://youtu.be/WY8Py40hlYc

 

If you lit a pound of 7:3:1 like that, there would be a big ole crater in the ground. And this test used a QM leader to light it, so there was a lot of fire going in there, much more than say, a static spark or something of that nature.

 

Aldo, sorry got a little side tracked there. Are you in the US? If so, it is relatively easy to find paper tubes that you can use for small salutes, so you wouldn't have to be hand rolling all of your casings. As far as traditional cylinders go, when you get some practice, rolling the casing and using end disks takes very little time.

 

 

WB

Yes I am from the US, I know its easy to get paper tubes, but I was just wondering if I could use plastic for single break salutes. I will be hand rolling almost all of my salutes after this though, I've got like 10 plastic casings and I don't really want to waste them on some color shells which will probably have crappy breaks (plastic cans kind of suck for color breaks if you've ever tried) I also have lots of pre-rolled 3" salute canister tubes which I probably be using for my later salutes, if I get tired of rolling them.

Edited November 16, 2014 by AldoSPyro

[Maserface]

From a lot of these replies, I have to assume that very few of you have actually ever made bottom shots. In hand rolled bottom shots, the flash does provide structural integrity. It is filled to the brim, and then settled, and repeated until solidly filled to the brim. This certainly eliminates the possibility of binary. I do the same filling and settling for hard walled cases anyway. I prefer my bottom shots and salutes to be safer by virtue of being totally solid. It has the added bonus of containing about 3x as much flash.

 

Bottom shots are integral parts of cylinder shell construction. You might as well get comfortable mixing flash it you intend to get into bigger or more complex shells.

Hm- I wouldn't have assumed the flash did much by way of support- but the only traditional bottom shots I've made have been rocket headers!

 

I guess lambetti do stiffen up quite a bit once they are closed and tied-

 

Thanks for the lesson!!

[Mumbles]

Yeah, sorry for taking it farther off topic.

 

If you're just looking for a useful way to get rid of the casings, salutes will be fine. They're not my favorite due to the dispersed plastic material, but they'll work fine. As stand alone salutes, they'll be fine, but I'd avoid using them as shell components. I'd give everything a good spray with static guard, and go from there. Pre-mixed or binary should both work. The biggest difference is that pre-mix will be louder due to more material and a better incorporation.

 

MrB, I think you'd be surprised at how solid the flash gets when properly settled.

[Nessalco]

 

We did a test at a club shoot this fall, lit one pound of TPA flash in an open tub, to simulate what it would be like if it were to ignite while we were working with it. I have a picture of the set-up if you'd like, it is pretty simple.

 

I'm assuming from how fast that burned it hadn't been granulated? The original patent specifies granulation with 2% NC with an acetone solvent. The granulated product burns more slowly in the open, but takes fire more readily when confined. Plus the granulation means you can pack bottom shots very solidly indeed and the salute is less likely to jet.

 

I've tested TPA flash in yellow cap plugs - ungranulated it works, sort of. You have to seriously prime the end of the time fuse to get them to reliably initiate. Granulated it works reliably with just a cut fuse, and gives an excellent report.

 

Aldo, sorry for dragging this even further off the rails...

 

Kevin

[AldoSPyro]

 

Aldo, sorry for dragging this even further off the rails...

 

Kevin

Its ok, lets see where this topic goes. Also I'd like to know more about the saftey ofTPA, I read the MSDS and it says that it can give you bladder and urinary track tumors from repeated exposures. That doesn't sound too good

[Nessalco]

Many of the chemicals we use have exposure risks. TPA is mild compared to many of them, but there are cautions. Use PPE and good technique. I usually wear a respirator when I mix this up, not so much because of the dust but because I granulate with acetone + NC, and the fumes from that are a problem.

 

Industrial grade TPA that I've gotten was shipped damp to minimize dust - you have to dry it out, and the dust really is irritating. Another reason the granulation is recommended, I suspect. The products of TPA combustion are mostly benign - CO2, CO, and traces of other gases- the military uses it for smoke grenades, and there have been extensive studies on its' toxicity after being burned. Not perfectly safe, but safer than other previously used products.

 

I have no dog in this race, though. I use standard flash where it is required. I prefer TPA when working with large amounts.

 

Kevin

[CannonBall]

Paper tubes are pretty much free, you can gather numerous different size tubes after NYE, i still have some from the last one.

[WonderBoy]

It was not granulated. I haven't read the patent, so I didn't realize that it was intended to be granulated. Is the granulation to keep it from self confining? A photo of the test set up.

 

 

 

What is the composition you've been using? I haven't tried it in cap plugs, but didn't have any issues with it igniting from timefuse in my 3/4" reports.

 

I have no problem mixing 7-3-1 (KClO4-Al-S) when I need it either. This stuffs just been fun to experiment with, it's a little cheaper, and makes me feel a bit better when I need to fill a few bottom shots.

 

 

WB

Edited November 17, 2014 by WonderBoy

[Nessalco]

WB - they didn't state the specific purpose of the granulation. I tried it and liked the handling and reduced dust a lot. I know from my experiments - a 500g batch burned openly - that it went up much more slowly than your example - kind of like a flare burning rather than a 'poof'. Took several seconds for the mix to be consumed.

 

I use a 70:15:15 formulation, mostly because it's easy to remember and adequately effective. The comp will work with from 1-100% TPA replacing the dark al, but as the TPA goes up, the mix becomes significantly more difficult to light. If the TPA falls below 12% the mix pretty much resorts to being as sensitive and likely to self-contain as standard flash.

 

Kevin