Flash powder safety

[dagabu]

Vrizla,

 

5413 H Super has long been known as the king of flash, it is not so finely divided that it causes and specific risk to spontaneous ignition nor does it retard the sensitivity to flame due to too large of a particle size. You seem to be a little hesitant about it so I guess I just have to ask. Do you have some 5413 and are hesitant to mix it?

 

There are much worse things to make flash from and 5413 is one of the widest regarded Aluminum for it's nice sharp crack! Please share the basis for your question, we seem to be bouncing around here and getting nowhere so just come clean, we can take it.

 

D

Edited March 22, 2010 by dagabu

[Ralph]

 

-additives always make flash more sensitive, except for flame retarding and gap filling chemicals.

 

 

charcoal is not a flame retarding chemical adding it will not increase sensitivity

 

 

 

With 5413H being of a very high mesh, and being flake shaped, this will produce a powder which I would expect to be pretty sensitive. However, an uncoated aluminium of half the mesh but without coating (such as Black000) will preduce an even more sensitive mixture, because the aluminium burns more easily.

 

Dark aluminium's have much of their sterin coating removed and (at least in Australia) are classified as uncoated

 

 

 

Being a chemist I'm not afraid of chlorates and using them, but I'm not ignorant either. When taking the proper precautions and having the right knowledge, potassium chlorate is one of the best oxidizers and chlorine donors around.

 

got to love chlorate such a lovely chemical

[Mumbles]

The classifications are done by the UN. Just because someone is shipping it incorrectly, doesn't mean that it's classified differently. If you look at the drum, I'm sure it will say UN 1309, which is the shipping code for coated aluminum.

[TheSidewinder]

Now there's an odd UN Number....

[Arthur]

There is no such thing as SAFE flash, from two perspectives;

 

1/ Flash annoys the neighbours then they complain to the authorities

 

2/ Flash by definition releases a lot of energy instantly.

 

There are several different uses for several different types of flash, slow flash will make a bright light ans little sound fast flash will use finer and darker aluminium and make bang and flash, the fastest flash will possibly explode at greater than the speed of sound make much noise and less light.

[Vrizla]

Dagabu, yes last year I purchased 5413 planning to use it in place of black powder for the report charge in certain items. I love those triple report rockets. However I decided that I wasn't ready last year and continued to practice with turbo pyro and other basic items. So I spent I summer in the shop and a winter reading on the web and found information sugesting that 5413 is less stable in flash then other aluminum, and when your mixing single digit micron aluminum in 70/30 flash you are really putting yourself at risk , that is more then larger micron aluminum. So I decided to ask some experienced pyro enthusiasts if there is any truth in this.

[dagabu]

I am not suggesting anything here so all of you safety fanboys can stay off my rear please.

 

I have seen 5413 flash with the addition of sulfur screen mixed on national TV for commercial manufacture with no problems and I have seen Mg and Chlorate flash 3" salutes that made it to 400' without flower potting.

 

I personally am cautious about all flash, it makes no difference to me what materials are used, it will leave you with a stump if it goes off. I try really hard to binary mix when ever I can. At PGI, you have to mix that way, on club shoots I mix that way, for cap plugs and inserts, I make no more then the contents of one shell per mixing and burn the rest (never in a pile) at the end of the day.

 

Diaper mixing is probably the safest method if using paper only, no butchers paper. If it goes off, you will have a bunch of problems but you should still have your hands. If you put a face shield on, you will still have your face and skin and if you wear shades, you may still have corneas.

 

I have to look but I think I have maybe 10 types of finely divided aluminum and all are useful but the 5413 H Super is my favorite for reports hands down.

 

With all of that said, you will get very nice reports with BP and Ti in a tightly confined package and you could drive across it all day and it wont go off, so if you are nervous, try some metals in you BP and spike it with layers of hemp or filament tape.

 

Danny posted a video of his BP and 5413 mix here. BTW, these are little tiny 1 gram inserts, I sold him the fuse and the cap plugs.

 

http://www.wichitabuggywhip.com/fireworks/rockets/capplugs/bpinserts1.wmv

 

D

[Vrizla]

I'm just trying to gather all the information I can. Like I said I treat this hobby with respect. Why no butchers paper. Someone said don't worry about the paper (I know everyone isn't an expert) I was planing on using a cut up brown paper bag. Was also thinking about newspaper or large sheets of parchmant paper that I have. However the parchmant is quilon coated not sure if thats good was going to look into that. Thats a really nice piece danny made.

[dagabu]

Good question, some butchers paper is plastic coated and can build static. I only had butcher paper the first time I diapered flash and it stuck to the paper and wouldn't pile up. The light bulb came on in my mind and I simple brought it out to the road and lit the paper on fire and got rid of it.

 

I didn't touch flash for quite a while after and seldom mix metals without remembering the Al standing on edge on the paper.

 

D

[Vrizla]

Well I made my first few batches of 70/30 and they preformed great as my rocket header. I still want to make a triple report, but first I have another safety question. I measured the headers by volume, but I like to be scientific with things and record exact amount. Especially when involved in more complex projects. So my question is: Is it safe to measure flash on a battery powered pocket scale using a paper cup as a container.

[FrankRizzo]

Well I made my first few batches of 70/30 and they preformed great as my rocket header. I still want to make a triple report, but first I have another safety question. I measured the headers by volume, but I like to be scientific with things and record exact amount. Especially when involved in more complex projects. So my question is: Is it safe to measure flash on a battery powered pocket scale using a paper cup as a container.

 

Absolutely.

[x77]

Would this procedure be safest?

 

Fill salute with KCLO4 and AL in layers. that is don't mix it. Allow the powders to sit on one another.

Finish building the salute.

Place in anti static bag.

Attach bag to a low rpm motor and timer arrangement.

Using the programmable timer, wait 1 min after power on, rotate for 2 hours, then turn off.

Theoretically would then be left with a constructed unit, with a mixed composition inside, and stored in an antistatic bag. No mixing was done by hand and no construction took place with mixed powder.

Edited May 17, 2010 by x77

[Mumbles]

Except for using potassium chlorate it sounds reasonable to me.

 

That being said I'd never go through the hassle. It sounds more on the order of production batches than amateur manufacture. If you're careful, you can safely work with it. The issue comes in where people are trying to run before they can walk and want to make flash right away, or try out some "recipes" they found on the internet.

[x77]

Except for using potassium chlorate it sounds reasonable to me.

 

That being said I'd never go through the hassle. It sounds more on the order of production batches than amateur manufacture. If you're careful, you can safely work with it. The issue comes in where people are trying to run before they can walk and want to make flash right away, or try out some "recipes" they found on the internet.

 

i am sorry, I meant KCLO4, perchlorate. IS perchlorate much safer to mix where this setup would be a waste of time?

Edited May 18, 2010 by x77

[x77]

i am sorry, I meant KCLO4, perchlorate. IS perchlorate much safer to mix where this setup would be a waste of time?

 

regardless, I wouldn't try this. I just couldn't help but think about the safety issue involved. Thee always has to be a solution.

Edited May 18, 2010 by x77

[50AE]

I think you will just complicate things. There's nothing wrong to

 

1. Spray your place with anti static solution.

2. Prepare a newspaper sheet

3. Pour your screened chemicals on it and diaper them several times.

4. Pour your mixed flash powder in a cardboard container and begin your job.

 

I think static can be the most backstabbing danger in this. Watch the humidity and spray with anti static.

 

Perchlorate and chlorate flashes are much more friction sensitive than the nitrate 5:3:2. Great care should be exerced while working with them. I think that the nitrate 5:3:2 flash is very little sensitive compared to the others above. I haven't done hammer tests with KNO3:MgAl though.

[dagabu]

Nitrate 5:3:2 flash isn't really flash at all, it is commonly referred to as slow flash but is about 1/4th as sensitive as pot perc and Al.

[Mumbles]

Would you mind explaining sensitive how Dave? It can be sensitive to impact, friction, static, etc. Different things are sensitive in different ways. Chlorate and sulfur is particularly sensitive to impact, where as chlorate and antimony trisulfide is particularly sensitive to friction for instance.

 

In all honesty, the worst thing you can do is to get comfortable. It doesn't matter if one mix is slightly safer than another, treat it as if it can go off at any time.

 

 

[dagabu]

If you have the best of AFN (four?), you will find a table showing you a list of hammer tests done to all sorts of comps with slow flash coming in at the bottom of the list. Anyone can widen the parameters out enough to claim anything they want, I am specifying impact as the empirical test for sensitivity as has every test I have seen for any flash composition.

 

"In all honesty, the worst thing you can do is to get comfortable. It doesn't matter if one mix is slightly safer than another, treat it as if it can go off at any time. "

 

I completely agree with your statement, 10 grams of BP under a 2" shell will punch a hole through your skull too.

[Mumbles]

Let me know if you can figure out where it was from. I took a look and didn't see anything relating to slow flash in relation to hammer tests in AFN 2-5. I don't doubt that slow flash is less sensitive. KNO3 isn't nearly as sensitive to sulfur or aluminum as potassium chlorate or perchlorate are.

 

I'll see if I can find my copy of Principles of Pyrotechnics, I bet it has something like it in it. I got some chlorate data from it for a talk I gave at the WPAG last year.

[Ventsi]

Well guys, keep in mind that impact is a pretty rare thing to happen in a shop. Unless you dropped a bunch of FP and then something on that....

On the other hand, I would love to see some friction and heat sensitivity tests done. Those apply MUCH more when mixing and handling.

[50AE]

Well, the 5:3:2 can be interpreted as an aluminum streamer. I do like the mix 5 KNO3 3 Al 2 S, it makes beautiful and cheap stars.

 

As for the real thing, I prepare KClO3 / Bright Al 7:3. Great care should be exerced with this one. The stearin on the Al makes the mix fluffy and greasy, it greatly reduces the friction, but still. Watch for static.

 

Mumbles, when you say "not to get comfortable", I agree at some point.

-You have to be concentrated and work with caution and great care. Watch out for every detail.

-But you don't have to be nervous and have your hair become white so soon.

Edited May 19, 2010 by 50AE

[dagabu]

Well guys, keep in mind that impact is a pretty rare thing to happen in a shop. Unless you dropped a bunch of FP and then something on that....

On the other hand, I would love to see some friction and heat sensitivity tests done. Those apply MUCH more when mixing and handling.

 

Two incidents from last winter that I had the make me disagree with you.

-I was pressing my hybrid rockets and I spilled some fuel on the table, I used a cotton rag to wipe it up and pushed the pile into a burn bucket (everyone should have a burn bucket). Apparently, I missed with some of the fuel and it ended up on the floor on concrete. Later, I dropped the long rammer (Aluminum) and when it hit the ground, it popped and I got a tiny wisp of smoke.

-I was sweeping my shop floor in March after working on a bunch of headings and I ended up with a pile of debris that I swept out the door to pick up with dust pan, the wind picked up and the top of the pile was blown away leaving only the powder on the concrete. There wasn't enough to sweep up so I left it and when I left for the night and locked up, I had to turn to key lock the bolt and spun on my toe and lit the pile off just by friction. No explosion, no fire, little smoke, more of a crackling sound.

 

I don't know what the powder make up was, I don't know much except it happened twice and I have changed my shop habits because of it.

[x77]

I think you will just complicate things. There's nothing wrong to

 

1. Spray your place with anti static solution.

2. Prepare a newspaper sheet

3. Pour your screened chemicals on it and diaper them several times.

4. Pour your mixed flash powder in a cardboard container and begin your job.

 

I think static can be the most backstabbing danger in this. Watch the humidity and spray with anti static.

 

Perchlorate and chlorate flashes are much more friction sensitive than the nitrate 5:3:2. Great care should be exerced while working with them. I think that the nitrate 5:3:2 flash is very little sensitive compared to the others above. I haven't done hammer tests with KNO3:MgAl though.

 

Would it complicate things by making the process less safe? Would the end result work or would it most likely not mix properly?

[Dystrophy]

Would it complicate things by making the process less safe? Would the end result work or would it most likely not mix properly?

 

 

Assuming you're talking about the static anti-spray, I'd say you'd be better off grounding yourself if you're worried about it. Its as simple as a metal wire and metal clip attached to a pipe or ground wire. If you're in a humid environment its less of an issue though if you're currently in the southern hemisphere or you tend to drag your feet, maybe it would be a good precaution.