My First Batch of Flash Powder

[MinamotoKobayashi]

I must be honest, I always was scared to manage Whiste Mix and Flash Powder, but today I tried to make a little batch (10 grams) of Flash Powder.

Sincerely, this was not so "little", because 0,20 grams of this mix created a deflagration so powerful that I clearly perceived an air displacement and I clearly felt the collar of my shirt vibrate .

Also, the flash was so intense that partially blind me (and I was 3 meters far away!).

To make this flash I followed this tutorial:

 

https://www.youtube.com/watch?v=7q72ALpJ2BA

 

but I used the formula: 58% KCLO4 and 42% German Dark and I used a very thin paper napkin to mix the individually screened chems for no more than 1 minute.

 

I know for sure that this mix is very sensitive, but just to try how sensitive it is, I putted a very small portion of this mix over and anvil and I hitted it with an heavy hammer: nothing happened.

So, I tried to crush and crawl that mix with the same hammer: nothing happened again!

I expected for sure a small deflagration. Anyone can tell me about this behaviour? The powder works at his best, but was not sensitive as expected.

Edited March 22, 2019 by MinamotoKobayashi

[Crazy Swede]

If you are so careful about mixing the ingredients via diapering on a paper, why the heck did you grind it afterwards with the handle of a spoon?

 

The friction sensitivity of perchlorate/aluminum flash depends on the fineness and quality of the ingredients, maybe your aluminum is not as reactive as it can be?

 

Also, your mix is unusually fuel rich and that might have lowered its sensitivity somewhat.

[BetICouldMake1]

 

 

Also, your mix is unusually fuel rich and that might have lowered its sensitivity somewhat.

 

 

I was thinking the same. 70/30 is the standard ratio. Also screening the chems individually before diapering can help with mixing since both the perchlorate and aluminum can clump in storage. You CAN screen mix flash but it's something most hobbyists stay away from. Can't say that I've even done impact or friction testing with 70/30 flash. I'm willing to take the word of those who have.

 

Side note. That might be the first youtube video on making flash that I've seen that doesn't make me cringe.

[MinamotoKobayashi]

Hi.

The video it is not mine, I never used spoons, only diapering.

To grab a small quantity of flash I always use a small flat piece of wood (the wooden stick of ice cream).

 

There are many kinds of flash as described in official Pyrodata site:

 

https://pyrodata.com/composition/flash-powder

 

I choose this composition for many reasons:

 

1. I own 1 KG of aluminum german dark (from Pyrogarage), the finest available aluminum powder on the market;

2. It make a damn fast flash powder;

3. It is not sensible to impact/frictions (as I have tested).

4. It doesn't not have sulfur that can increase impact/friction ignition.

 

The only disvantage is that the german dark is pricey, but I prefer to spend more and to be safer than the exact opposite ...

[Carbon796]

Spending more, doesn't make anything safer.

 

Just because its posted on a website, doesn't mean its ideal.

 

German dark being the finest aluminum powder on the market, is personal opinion or lore, not necessarily fact.

 

It may not be as sensitive as you were expecting, because that comp is not an ideal one. And being as its your first time making it, you have no reference point to gage it by.

Edited March 22, 2019 by Carbon796

[kingkama]

First the ratio is 70-30, your is under oxidated, so, you will obtain a blinding flash more than a powerful boom, the perchlorate mix is friction sensitive and it's reported to be spark ignited. Don't be too confident, it's not so sensitive as the description can suggest but because of that you will be pushed to forget that you are playing with a dangerous mix.

[NeighborJ]

Often it is impurities which can make flashpowder extra sensitive to impact and friction. Chlorides will certainly make thing more exciting, thats not to say even the purest chems won't be friction sensitive. Under enough force it will ignite.

The thing that makes flash so dangerous is the violence it contains "if" it should ignite at the wrong time.

Edited March 22, 2019 by NeighborJ

[Ferret]

Exactly, while flash is used in pyro since it is safer than some other mixes, the whole issue is that if it does go off accidentally the results can be very bad. If you were working with 100 grams of blackpowder and it went off in front of you, you would have some time to flinch and probably sustain some bad burns.

 

Flash self-contains at something like 3 grams. So if you were working with 100 grams of flash and it accidentally went off, it would not burn, it would detonate. You would have no time to even flinch and if your hands were near it - you might lose some fingers.

 

This is why all the "overly safe" methods are often prescribed. You can't risk any chance of ignition. It may not be "that" static or friction or impact sensitive in testing - but don't expose it to those triggers when you are actually working with it anyway.

 

Also, is it just me or does it seem like there are a lot of questions about flash recently?

[spectra1]

70/30 flash does not self contain at 3g sorry but that is incorrect.

[MinamotoKobayashi]

0.2 grams of my 58% KCLO4 and 42% German Dark is scaring enough, it seems a little detonation because I perceive vibrations around me, so I think that 3 grams is enough to damage eyes, ears and fingers if ignite in front of me.

 

Excuse me, but if the flash is so sensitive, everytime that a chinese guy paste a shell containing flash risks to dead?

Everytime that a shell falls on the ground will detonate?

Everytime that a shell will be shot with a mortar will explode early?

 

I'm about to fill a 2" shell with my not-friction not-impact sensitive flash. It contains about 80 grams of flash. I wish to paste it with some layers of gummed paper

for a heavy confinement to create a very loud bang (a sort of salute rocket). At this time what I can expect? That the flash will ignite while I'm rotating the shell to paste it?

That the shell will explode if accidentally falls on the ground? That the shell will explode just when the rocket ignite?

I'm a little bit confused, sorry.

Edited March 23, 2019 by MinamotoKobayashi

[kingkama]

The major issue is a direct friction between powder ad an hard surface or static when mixing,when in a case the risk are low or null. If your problem is to be safe this is not a risks free hobby you can reduce it but not nullify so work in a clean place and after manipulation clean all with a wet tissue.

[NeighborJ]

The friction sensitivity warnings mostly refers to things you normally dont think of as causing friction but actually create a tremendous amount of pressure. Scissors are one such device. The force applied to the razors edge will deliver an inconcievable amount of force to a grain of perclorate at the cutting edge causing ignition. Metal objects or tools with sharp edges being used on a metal or hard surface can also create an ignition risk. Static charges in dry climates pose risk.

 

Flash is waiting to bite you from any unobserved danger. The chinese use no metal in their workshops or as little as possible and are observant of the few items that are. They also use a cheaper form of "flash" which is often using a blend of KHP, charcoal, perlite or a number of other chems. If they have an accident, they need only to find another group of children who are willing to accept the risk for a full belly.

 

Once a shell is filled the danger and risk goes way down. There is no longer the risk of capturing dust between pinch points and it can be handled but you wouldn't find me playing baseball with salute shells. It only requires that it be given the respect it demands.

 

Noone is telling you to never ever use flash but it is wreckless to assume that it is not friction sensitive because your test failed to ignite it. Assume that it is sensitive and take every precaution concievable and there is still the occasional accident. Everyone's level of acceptable risk is different, if that risk sounds acceptable to you then by all means give it a shot. Our goal here is to inform you as thuroughly as possible so you can make an informed decision.

Edited March 23, 2019 by NeighborJ

[Ferret]

NeighborJ is spot on again

 

I don't remember what the quantity for self-confinement for 7:3 is, but in terms of orders of magnitude I am not far off. Search around on the forum and you will find countless cases of "I set off a loose pile of 7:3 F and was surprised it went boom instead of burning"

 

Here is a post from "rogeryermaw";

"i can attest to Brad's incident with the flash. i had a similar brain fart thinking a small pile of unconfined flash would go off with less than spectacular results...wow...the lesson i learned was to never underestimate any pyrotechnic composition. EVER!

i had probaly 9 or 10 grams of flash mixed on a piece of waxed paper, scooted the pile to the center, bunched it up and stuck in probably 10 inches of visco. i placed it in the yard about 50 or 60 feet from the house, lit it and booked. the shock wave knocked pictures off the wall in the house!!"

 

The post referred to by brad:

"I don't know how much was left, my guess would be 3 or 4 grams maybe, but it had rice hulls mixed in with it so that makes guessing the exact weight more tricky. I wanted to get rid of that little bit of flash, and have some fun doing so.. so I took it out into the driveway, poured it in a small pile, and put a long piece of visco in it. I lit the visco, then ran back into the barn and left the door open so I could still see the bright flash. My assumption was that it was going to make a super-bright flash but not really have much report. About 30 seconds later, BOOOM..... im talking a boom like an M-80!!!! Rocks peppered the polebarn, and I about pissed myself. I went out to look and there was a small crater in the rocks."

 

From my own experiences with flash, these tales are not a stretch at all. The confinement quantity for F is very low. I thought I first read of the confinement quantity on this forum, but I can't find that thread now. In the same thread it was stated that the confinement quantity for blackpowder is on the order of thousands of pounds.

Treat flash however you want, it's not my limbs at risk at the end of the day. We are just trying to promote safety. Flash is used in pyro since it is "the safest" high-energy comp we can use, but that doesn't mean we should treat it carelessly - that is the only point we are trying to make.

I never understand why people want to argue that flash is "safer than it is made out to be". Hammer on concrete test means nothing. That is not science.

[Mumbles]

Flash does not detonate under normal pyrotechnic uses. Any perceived detonation is due to imagination or lack of experience. The self containment mass as well for normal 70/30 is closer to 50g. That's not to say that's the minimum, as it certainly could at a lower mass. That's more the mass it almost certainly will self confine.

 

Flash does go off with a firm hammer strike as well. I would not take your experience as typical. It's likely due to formula, or perhaps questionable materials.

[rellim]

I made some 70/30 out of bright flake recovered from aluminum paint. It burned as slowly as a star so I made some micro-stars with PP ball lacquer. These reliably make a loud crack and flash on the second blow in a rusty hammer test.

[Mumbles]

That has more to do with the rust, and less with actual impact sensitivity.

[Wiley]

I will say that the best way to mix batches anywhere from 1 to 10lb is with a screen. I don't know of any hobbyist who, if needing to make batches around 10lb in weight, would want to diaper it. Edited April 7, 2019 by Wiley

[Piccaso]

Before I learned to not make things off of random peoples YouTube videos. I made a batch of what was described as a green strobe compound but it was not, turned out to be a type of magnesium and barium flash. 3 grams of it in a paper wrapper scared the crap out of me and knocked the letters off my menu board in the shop. I have no interest in making flash after that if I can avoid it. I am an auto tech by trade and need my fingers. The stuff is no joke and should be treated with the utmost respect. I was in a 8" field artillery unit in the army and am used to loud explosions but the small amount it took to do what it did made an impression on me I will never forget.

Edited April 19, 2019 by Piccaso

[Maximo]

I'm wondering since I'm new to this, how do you tell the difference from one mesh size to another and where can I purchase screens? Also I'm wondering... I just purchased 2lbs of 5 micron AL but not the German dark. Can I just mix in the 5% by weight powdered charcoal or since it wasn't milled with the charcoal in the first place will it forever be non reactive?

[pyrokid]

I recommend that you mix a small batch with the aluminum in its current state and see if the performance suits your needs before modifying it.

[CrossOut]

I will say, given mild containment, flash will detonate in small quantities.. firecrackers are a perfect example of this. (Yes firecrackers are detonations) even at .050g. you don't need much either! So.e a cases, a single layer of paper is more than enough given a quality. Triangles are a perfect example of your having 1 or 2 layers of paper forcing 0.5g to det. Other flash compositions I've used can detonate unconfined in very small amounts. (0.1g) is the smallest unconfined I've experienced to detonate.

Edited April 27, 2019 by CrossOut

[Mumbles]

I'm wondering since I'm new to this, how do you tell the difference from one mesh size to another and where can I purchase screens? Also I'm wondering... I just purchased 2lbs of 5 micron AL but not the German dark. Can I just mix in the 5% by weight powdered charcoal or since it wasn't milled with the charcoal in the first place will it forever be non reactive?

Mesh sizes are just a measure of particle sizes. You differentiate them by measuring what you have. This is generally done with screens, though very fine materials are measured in other ways. Screens can be purchased from a number of suppliers such as McMaster Carr, Grainger, or other industrial suppliers. Wire cloth is another search term that might help.

 

I'm curious what 5% charcoal by weight has to do with anything. That's not how german dark is made. Plus you more than likely have atomized aluminum anyway.

 

 

Crossout, Self confinement is different than detonation. I'm in the flash does not detonate under normal pyro applications camp.I would also prefer to further this conversation in the HE section.

[hollon]

Flash definitely is friction sensitive and can definitely be set off with a good whack on a steel plate, though if you're going to do this, do only small small amounts and should put on ear and eye protection just in case.

 

I also agree with mumbles that it does not detonate, its a rather quick deflagration. If I remember correctly it's at 2000 m/s which isn't high enough to qualify for a HE. Though I'm not an expert, so whoever knows more can fill in the rest

 

Also mumbles that link to the old forum in your sig now directs to a spam site.

Edited May 16, 2019 by hollon

[Mike71]

70/30 perc is not that sensitive

Just wstch for static

Mix on humid days and use static guard

Chlotate and mag are a diffrent story... im scared to death of it...

Respect it and be cautious

[Muslickz]

I personally use a 70/30 and also use German Dark as my go to..

 

It is a little more costly but produces a fantastic product.

 

I usually make no more than 10 or 20g at a time, Unless I'm working on something that specifically requires a larger amount.

 

And even then I usually mix in smaller amounts and combine when needed.

Edited August 11, 2020 by Muslickz