Kevin4393 Posted August 2, 2010 Posted August 2, 2010 Hello, I've been involved it small pyrotechnics for a few years now( mostly BP and fireworks stuff) and have recently decided to try to make a batch of flash powder. After a little browsing I found that I need potassium perchlorate and aluminum in a 7:3 ratio. So I purchased one pound of potassium perchlorate (http://www.hobbychemicalsupply.com/servlet/the-19/pyro-chemicals-potassium-perchlorate/Detail) and some fine mesh aluminum from ebay. (http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=190349248624&ssPageName=ADME:L:PMR:US:1123#ht_5748wt_1086) So I go make a 10 gram batch which i measured using an electronic scale. I mixed the components completely over a couple minutes in a small zip lock baggy. I then took out a 1 gram sample from the batch and tried to light it. Nothing really happened except for a tiny amount of sparks. Where did I go wrong in my process? Were the chemicals I bought incorrect? I'm sorry ahead of time if this is a noob question!
mike_au Posted August 2, 2010 Posted August 2, 2010 some fine mesh aluminum from ebay.This isn't ideal but I would have still expected it to burn reasonably quickly. I mixed the components completely over a couple minutes in a small zip lock baggy.You are lucky it was a dud batch. Rubbing things against a sheet of plastic is a terrific way to generate static and static is a great way to create sparks. A spark near 10g of flash could easily cost you your hand. Please do some more reading especially about safety before you try this again. In the process you will probably come across a couple of common problems along with information on how to solve them.
Kevin4393 Posted August 2, 2010 Author Posted August 2, 2010 Thanks for the reply. Any reason why it might be a "dud batch'? I will be sure to read up on the proper methods of handling of flash powder after hearing that!
jimbo Posted August 2, 2010 Posted August 2, 2010 if your aluminium is atomised or spherical most likely will be your problem, you want flake type al,I've heard bright flake works but you really need german dark or indian blackhead then you can't go wrong from there, start off by making 1g batches to be safe or as low as your scales can reliably measure.
Twotails Posted August 2, 2010 Posted August 2, 2010 Im not quite too sure on why it did not preform. You said it dosent burn, is that via an open flame, visco, or blowtorch? you Al seems to be coated. Are you sure you have the amounts correct?
pyrochris732 Posted August 2, 2010 Posted August 2, 2010 you probably had the wrong aluminum. Although atomized Al with KCLO4 will do a lot more than just spark if your ratios were correct. Dont mix flash powder in a bag, too. Why risk an accident?
Kevin4393 Posted August 2, 2010 Author Posted August 2, 2010 Im not quite too sure on why it did not preform. You said it dosent burn, is that via an open flame, visco, or blowtorch? you Al seems to be coated. Are you sure you have the amounts correct? I tried both visco and open flame and neither worked. And I am positive that the amounts are correct
inonickname Posted August 2, 2010 Posted August 2, 2010 (edited) Try light it with something with magnesium in it (ribbon, or even a sparkler). If it lights, then there's a fair chance whatever your Al is coated with is interfering with reliable ignition. You'll then have to go about fixing that. Flash powder should ignite. Easily. For future reference, try a smaller batch first and rather than using a static-o-matic zippy, diaper it together on a non-glossy sheet of A4 paper. Edit: What's the accuracy of your scales like? I've had to tolerate 1g increment ones for a while, and it sucks. I just ordered a 0.01 gram jeweler's scale as I'm starting to do more smaller, but powerful comps. Edited August 2, 2010 by inonickname
dagabu Posted August 2, 2010 Posted August 2, 2010 KCLO4 usually comes in a pretty coarse condition and likely needs to be further ground to get the report to light. Almost any finely divided aluminum is fine for reports but homogeneous mixing and finely ground KCLO4 are essential for effective lighting. I understand the rational behind the diaper method that is used by most and that is used for more then one reason and is one of the safest ways to mix the ingredients. PGI is coming in 6 days and there will be NO open flash allowed but rarely is there a single dud with binary mixed salutes. This should raise some eyebrows here since there seems to be some consensus that it has to be well mixed to work well. I have some of this same Al along with about a dozen others and all of them will report when used with a good KCLO. That is where I would start.
mfstraydog1 Posted August 2, 2010 Posted August 2, 2010 i agree with dagadu sounds like yopur KClO4 needs to be ground down.
Skycastlefish Posted August 2, 2010 Posted August 2, 2010 My first batch of flash had the same problem. It turned out to be the Al I bought from ebay. I purchased it for a thermite experiment and it worked great for that, but didn't cut it for the flash. I went back to the sellers page and at the bottom in tiny letters it said "Al won't work for flash." It didn't say why, I presume it had to do with a lack of quality control and/or particle shape and size. Now I only use cheap Al for thermite, everything else I get from trusted sellers. PS I know it sucks to waste chems, but I highly recommend you don't try to salvage that batch. Any method you might try to get the particle size smaller for the already mixed comp would certainly require a dangerous amount of friction. Just my 2 cents.
Kevin4393 Posted August 2, 2010 Author Posted August 2, 2010 I used a little bit of magnesium to ignite the the flash powder which worked well. Unfortunately my scale(it's a small electronic postal scale) is only accurate to a gram and over, but I think it will suit my needs. So from this would it be right to conclude that the problem is that my cheap aluminum is coated with something?
Ralph Posted August 2, 2010 Posted August 2, 2010 if your aluminium is atomised or spherical most likely will be your problem, you want flake type al,I've heard bright flake works but you really need german dark or indian blackhead then you can't go wrong from there, start off by making 1g batches to be safe or as low as your scales can reliably measure.bright aluminium does infact work for flash it just needs some confinement it is used by people making large bottom shots quite a bit due to its lower price. atomised aluminium can infact be used for flash it just needs to be fine enough to the point that it has a similar surface area and there is discussion out there that it is actually louder than flake. sounds like you should stear clear of flash but if you confine it you should find it works
Algenco Posted August 2, 2010 Posted August 2, 2010 I've had my fill of loud booms, we know how to make quiet/subdued flash, now I need to learn how to make quite bursts
dagabu Posted August 2, 2010 Posted August 2, 2010 I've had my fill of loud booms, we know how to make quiet/subdued flash, now I need to learn how to make quite bursts make perfect shells that will shatter with low pressures.
Mumbles Posted August 2, 2010 Posted August 2, 2010 bright aluminium does infact work for flash it just needs some confinement it is used by people making large bottom shots quite a bit due to its lower price. atomised aluminium can infact be used for flash it just needs to be fine enough to the point that it has a similar surface area and there is discussion out there that it is actually louder than flake. sounds like you should stear clear of flash but if you confine it you should find it works The data and people who found that atomized Al makes the loudest salute is suspect to say the least. It can be made to work though.
Algenco Posted August 2, 2010 Posted August 2, 2010 make perfect shells that will shatter with low pressures. That shall be my quest
dagabu Posted August 3, 2010 Posted August 3, 2010 The shell has to be made OVER the contents, no equators, no fracture lines, no weak spots. I have seen two or three shells that were made specifically to break as sound free as possible in a tribute to the fallen and they were coated rice hull broken in a news paper shell laid up by hand, layer by layer over the innards.
Algenco Posted August 3, 2010 Posted August 3, 2010 well, I have some light 3" hemis made from newspaper, Now I have a mission !
al93535 Posted August 3, 2010 Posted August 3, 2010 Just looking at the picture I can just about be sure that its atomized aluminum. Stearic acid coating will not prevent flake aluminum from working properly.
Bonny Posted August 9, 2010 Posted August 9, 2010 Edit: What's the accuracy of your scales like? I've had to tolerate 1g increment ones for a while, and it sucks. I just ordered a 0.01 gram jeweler's scale as I'm starting to do more smaller, but powerful comps. Sounds like you're making some pretty teeny weeny batches if you need a scale that accurate... Just looking at the picture I can just about be sure that its atomized aluminum. Stearic acid coating will not prevent flake aluminum from working properly. As Al said the coating should not stop the flash from working. I've made flash salutes with 200mesh atomized, coated flake and dark Al , they all worked just fine.
dagabu Posted August 10, 2010 Posted August 10, 2010 I dont want to raise the eyebrows of the mods too much but I am firmly in the camp of making one batch to cover many projects. This may be contrary to much of what you have been told but the greatest dangers should be mitigated first and then work to your lowest danger. Storing F, while it may not your first choice, is safer then making small batches. I make 1 kilo and make a bunch of bottom shots and inserts, store them in the mag and I sleep fine at night. Making 100 batches of 10 grams would expose me the the possibility of a friction explosion 100 times. The greater the risk, the less exposures to it is favorable.
Gunzway Posted August 10, 2010 Posted August 10, 2010 Yeah, you're totally right there dagabu. It also wouldn't make much of a difference if you had a 100gram batch go off compared to that of a 1kg batch. I'm sure the results would be the same either way, probably the latter making you feel more comfortable as you know it'll do the job and it would probably be more instantaneous.
Cookieman Posted August 10, 2010 Posted August 10, 2010 Yeah, you're totally right there dagabu. It also wouldn't make much of a difference if you had a 100gram batch go off compared to that of a 1kg batch. I'm sure the results would be the same either way, probably the latter making you feel more comfortable as you know it'll do the job and it would probably be more instantaneous. Welcome back!!! I'ts nice to see you posting again.
Alireza Posted March 4, 2013 Posted March 4, 2013 Hi all. I have the same problem here. I JUST made 10grams of flash powder using 7g KCLO4 + 3g Al powder( > 400 mesh). but it just won't ignite !I also have Magnesium powder (230 mesh) which works fine in the composition. There's another thing I need to know. I've been searching a little bit and noticed a few videos of testing flash powder. The thing is my flash powder (magnesium + aluminum) doesn't burn as fast. I need it to literally explode, loud and fast.So, is there anything I'm missing or any tip I could use to make a more powerful (and absolutely ignitable!) flash powder ?
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