Sciencemadness Discussion Board - Flash Powder

Flash Powder

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h0lx - 14-11-2006 at 13:50

That's why I have a dry extinguisher beside my lab entrance

Jdurg - 14-11-2006 at 17:53

Quote:

Originally posted by h0lx
That's why I have a dry extinguisher beside my lab entrance

Smart man.

h0lx - 17-11-2006 at 08:56

I made a pic of the turnings too. the wooden object is a matchstick, so you get an idea, of how big they are(nah, actually it was for scraping them together, but it serves 2 purposes then). I hope the image is not too big

photoguy - 25-12-2006 at 11:56

I use flash powder in my traditional wooden box camera photos. I used to buy the stuff for years, but became impatient when the price soar in the late 90's due to legal issues. Now I just make my own... plain and simple.

I have used the following:

Permanganate based flash w/ MagAl + Sulphur:

These powders seem to be best if no Perchlorate can be found. But -permanganate flash compositions tend to be bar-none the MOST dangerous type around! Always gives me the best results for photography.

KNitrate/MagAl:

pretty good to.... but the intensity of the flash is usually too bright - and burn time is too long to be of real use, unless I keep my fstop very high - say f11+

--- commercial stuff:

Always the best - perchlorate/Al or perchlorate/MagAl- same results as permanganate.

[Edited on 25-12-2006 by photoguy]

Sauron - 25-12-2006 at 12:33

Glycerine is oxidized by KMnO4 in finely divided form, to acrolein, acrylic aldehyde, which is an important industrial feedstock, that is also a proven human carcinogen.

The structure given several posts above is incorrect as the hydroxyl groups were eliminated. There's a double bond at one end of the three carbon chain and an aldehyde function at the other. It's a very famous rxn. I think I first did this in my garage when I was maybe 13-14, now about 42 years ago.

Aqua_Fortis_100% - 25-12-2006 at 23:10

Quote:

Mensagem original enviada por photoguy
I use flash powder in my traditional wooden box camera photos. I used to buy the stuff for years, but became impatient when the price soar in the late 90's due to legal issues. Now I just make my own... plain and simple.

I have used the following:

Permanganate based flash w/ MagAl + Sulphur:

These powders seem to be best if no Perchlorate can be found. But -permanganate flash compositions tend to be bar-none the MOST dangerous type around! Always gives me the best results for photography.

KNitrate/MagAl:

pretty good to.... but the intensity of the flash is usually too bright - and burn time is too long to be of real use, unless I keep my fstop very high - say f11+

--- commercial stuff:

Always the best - perchlorate/Al or perchlorate/MagAl- same results as permanganate.

[Edited on 25-12-2006 by photoguy]

could be this Magnalium/nitrate/S flash more stable and storage than Al/nitrate/S or Mg/nitrate/S ???
(I remember read here which in an experiment from Garage Chemist, he not observed reaction of Magnalium and NaOH solution(even hot solution!), then i think which this MagAl probably will be resistant against alcalines products formed from nitrate and the metal..even maybe without formate this... Additionally ,coated MagAl powder can be better than MagAl without coating..)

[sorry about my very poor english...]

Zinc - 12-1-2007 at 05:57

2 days ago I lighted a small amount of NaNO3/Al flash powder (I used Al powder extracted from paint). It burned slower than the NaNO3/Al/S flash powder.
What is the best ratio for the NaNO3/Al flash powder?
I have read that the best ratio is 50:50 by weight. Is that true?

Also is the NaNO3/Al flash powder safer than the NaNO3/Al/S flash powder?

[Edited on 12-1-2007 by Zinc]

quicksilver - 12-1-2007 at 07:52

Just my opinion but....There is no "best ratio" it depends on what you want to accompish. 50/50 Sounds like too much fuel. (Perhaps start at 70/30) Remember, all metals powders may contain variety in their sizes. So your Al may have some material that is smaller and more volitile than you know: take advantage of that! Take the container and tap it or shake it. The smaller material will settle on the bottem. Use that. It may be sub-sieve in size while other larger material will be on the top of the container. But what is also important may be that there may be an issue with temp sensitivity. For that, a material to lower the ignition temp may help (S or Sb2S3) like you did before! Safety is an issue that is best met by working with ALL deflagrants as if they were so very sensitive that any exposure to ignition is totally avoided. Treat it all like it will flash over the same. Don't look for a formula that lets you get comfortable! The more wary you stay; the safer you stay. Always assume that you have a very dangerous material in any deflagerant. All energetic materials are as dangerous or as safe as the handeling them are met with. Armstrong's can be worked with if it is whetted. BP has caused serious accidents from it's dust in the air being exposed to static. Remember the ammonium perchlorate accidents in Nevada or the ammonium nitrate accident in texas City. Those were generally "safe" materials. Looking for a "safe" formula is not the best idea due to an underlying feeling that it can be handled in a more casual way. Check out the PGII's safety issues with general construction protocals; it will set you mind at ease. Following them you tailor your methods to the material to an extent but maintain certain standards all the time. That way when you work with a material, you target what you want, not what you feel you need to compromise to use.....JMO

nitro-genes - 12-1-2007 at 07:58

I suppose you used dark german aluminium or equivalent? Straight KNO3 or NaNO3 doesn't even ignite with atomized or even flake Al in my experience, even with dark aluminium the reaction is very slow without any sulfur. So, depending on your aluminium powder, it can be very safe without any sulfur. Just like with gunpowder, it is mainly the hot sulfur vapours that run very fast trough the mix, speeding up the reaction and lowering the ignition temperature...
Personally I prefer 50/50 KNO3/Al, because of NaNO3's hychroscopicity. I use flake Al, which makes the mixture unable to ignite by flame, but sensitive to a small detonator. The 50/50 mix has a very bright flash (not as bright as NaNO3 though), and an extremely low pitched report. Great new year's charges!

[Edited on 12-1-2007 by nitro-genes]

Zinc - 12-1-2007 at 16:32

How about Na2Al2O4 and Al?

DeAdFX - 12-1-2007 at 20:32

Sodium Aluminate is just a mixture of Aluminum oxide and Sodium oxide. That thermic mixture isn't going to do much if anything at all.

Zinc - 24-1-2007 at 12:50

I have tried the BaSO4/Al (3:2) flash powder(I have heared that this is a powerful mixture). I used Al extracted from paint so it contained some residual organic material and I added a small amount of sulfur (to sensitse the mixture). First I tried to light it with a propane/butane torch but it didn't ignite. Then I tried to ignite it wit magnesium ribbon but it also didn't ignite.
Does anyone know why?

h0lx - 24-1-2007 at 13:02

has anybody tought of using Oxygen rich explosives for oxidisers in flash? HNE would make quite an energetic mixture with Mg or such IMO.

chemoleo - 24-1-2007 at 18:14

Zinc, I've always meant to try this particular mixture, BaSO4/Al. First of all, did you make stoichiometric calculations? What grade was your BaSO4, how fine is the Al? Both need to be very fine.
Then, from my experience with CaSO4/Al, you need *excessive* ignition power. That is, several sparklers tied together, placed into a pressed mixture of BaSO4/Al.
If it doesn't work still, add a small amount (i.e. 10% of the total weight) of powdered sulfur, and increase the amount of Al accordingly i.e. to form Al2S3. This should serve, similar to the SiO2/Al thermite, as an energetic additive that keeps the reaction going.

Flash Powder

CWAnalyst - 25-1-2007 at 02:17

Hello fellas,

try to use BaSO4 with less than Bassanite water content as it renders the mix very difficult to ignite.

As a starter powdered Fe/KMnO4 will work.

regards

CWAnalyst

Zinc - 25-1-2007 at 05:40

Quote:

Originally posted by chemoleo
First of all, did you make stoichiometric calculations?

I mixed it with the ratio 3 parts of BaSO4 and 2 poars of Al
and I added a small amount of sulfur.

Quote:

Originally posted by chemoleo
What grade was your BaSO4, how fine is the Al? Both need to be very fine.

The BaSO4 was dried in the oven for 2 hours at 150 degres celsius and powdered with a mortar and pastelle for a few minutes. The Al was extracted from paint so it contained some residual organic material.

Bert - 25-1-2007 at 07:48

Quote:

Originally posted by Zinc
I have tried the BaSO4/Al (3:2) flash powder(I have heared that this is a powerful mixture). I used Al extracted from paint so it contained some residual organic material and I added a small amount of sulfur (to sensitse the mixture). First I tried to light it with a propane/butane torch but it didn't ignite. Then I tried to ignite it wit magnesium ribbon but it also didn't ignite.
Does anyone know why?

If you haven't read this re-post on E&W, you might wish to do so.The Few, The Proud, The Sulfates

photoguy - 26-1-2007 at 00:30

...interesting! Never tried BaSO4/Al before... doubt it would be a powderful as Permanganate flash.

Zinc - 26-1-2007 at 07:32

Quote:

Originally posted by photoguy
doubt it would be a powderful as Permanganate flash.

But it is safer.

quicksilver - 27-1-2007 at 07:17

Quote:

Originally posted by Bert

If you haven't read this re-post on E&W, you might wish to do so.The Few, The Proud, The Sulfates

That was a great article. I remember Haarmann
from rec.pyrotechnics, etc. I received that from PGII also and really liked it. (& it was no suprise that NBK had a tantrum when the guy didn't used "% additional").

The issues of particle size also influences ignition in tough to ignite materials.

Zinc - 30-1-2007 at 10:09

Yesterday I tried to light a mixture of KClO3 and Al powder. The Al (analitical grade) was in the form of airfloat and shiny flakes. The KClO3 was 20-30 years old. I tried to light it with a propane/butane torch. It did not burn.
The KClO3 melted and decomposed.
Does anyne know why?

Bert - 1-2-2007 at 05:19

Try it again with a SMALL batch, adding a bit of Sulfur. Chlorate and Aluminum by themselves do not make a good flash.

quicksilver - 1-2-2007 at 06:57

Fuel / oxidizer mixes need to be intimate and the particulates need to be SMALL. The particulate at sub-sieve size (single digit micron size) is optimum. Crush the materials individually then mix them very completely. IF your fuel is small enough you should have good results. However the term "analitical grade" doesn't specify the size. IF you use 90 mesh flake Al you won't get the results that you would if you used paint-grade Al that was ball-milled down to dark. Niether would it be best if the KCLO3 was lumpy, etc.
I have seen Alcan 813 flake ball milled to some of the best dark Al in less than 24 hours using tank / tractor ball bearings in a ball mill. Likewise I have seen spherical aluminum ball milled to a flake that was sub-sieve. Both worked as well as ANY of the dark German Alumiinums. Eckart's sub-sieve Al is a very special aluminum. Eckart is a pigment manufacturer! They make their own Al with a process similar to that in that they shave and crush non-coated Al down to single-micron size and then tumble it so the smallest sizes sink to the bottom of the containers. Sraining it from there they keep the smallest particulate material for silver inks. In any batch of any particulate the smallest sizes eventually sink to the bottom of a container that has been subjected to bumping, etc. You can obtain differing sizes yourself using that technique.
Brittle material like Mg is shipped in limited size containers for that reason. DOT has regulations that maintain the "shaving" phenomenon from happening in large drums by limiting size. In materials like Zirconium that is very important. I once had a container of brittle material (Ti) that was subjected to shaving via being left in a truck and the bottom most layer was certainly sub-sieve in size.
Particulate size and intimacy of mix are the most important factors in making fuel / oxidizer mixes. Whetting mix- techniques using etoh is very effective for F/O materials and in fact is the only way that some people/companies mix pyrotechnics (industrially). The standard mil flare of teflon/magniesum is always mixed with a fluid of thin NC laquer. That gets that particles close together and maintains them. Seperation is much more difficult if the particles are in a binder, of course.

[Edited on 1-2-2007 by quicksilver]

Zinc - 4-2-2007 at 13:12

Quote:

Originally posted by Bert
Try it again with a SMALL batch, adding a bit of Sulfur.

I do not have KClO3 any more.

Tooday I ignited a small amount of KBrO3/Al/charcoal.
I belive that it didn't burn fast because the chemicals were not fine enough.
Does anyone have expirience with potassium bromate flash powders?
If yes please post some information.

[Edited on 4-2-2007 by Zinc]

woelen - 4-2-2007 at 13:18

I make KBrO3 from KBr quite easily, at high purity, and it is a nice chem for conveniently making bromine, but for flash purposes it simply is too sensitive. KClO3/reductor mixes already are quite risky, this is even worse with KBrO3/reductor mixes. Too violent and too friction sensitive. If you value your hands and don't want a similar experience I had with K3CrO8/P/Al, then be VERY careful.

KBrO3 does make flash, but for practical purposes I think it is not useful.

Zinc - 5-2-2007 at 13:42

Today I tried to ignite a small amount of KIO3/Al/charcoal.
I tried to ignite it with a propane/butane torch but it didn't burn.
The KIO3 melted and decomposed.
Does anyone know why?

A little of topic but when a mixture of KIO3 and S is ignited it burns with a pink collor and a large amount of iodine vapur is released.

DeAdFX - 5-2-2007 at 14:41

2KIO3 ---> 2KI +3O2

16KI + S8 ---> 8K2S 8I2

Sulfur is a stronger oxidizer than Iodine is my guess....

woelen - 5-2-2007 at 15:00

Zinc, the KIO3/Al mix should definitely work, but it is somewhat hard to get ignited. KIO3 is not a really strong oxidizer and its decomposition temperature is fairly low. Probably the ignition temperature of KIO3/Al mix is above the temperature of decomposition of KIO3.

I myself made KIO3/Al mix, with just a tiny pinch of red P added. It makes ignition of the mix much easier, and the mix burns with a bright white flame, but not really fast. Pink smoke is produced.
Try the KIO3/S mix, with some of the S replaced with Al. It may give a slow burning, but brightly burning mix.

But essentially, KIO3 sucks as an oxidizer for pyrotechnic purposes. I have similar tame experiences with K2Cr2O7 and K2S2O8. If you have KIO4 or NaIO4, then also try that. That stuff is really WOW, compared to KIO3. The difference is huge.

If I have to make an ordering of the (per)halates as pyro-oxidizers, then I think the following ordering gives a good comparison, when evaluating ease of ignition:

KBrO3 >= KClO3 >> KIO4 > KClO4 >> KIO3

KIO3 is less energetic than KNO3 and it also is less energetic than many metal oxides at higher oxidation state, such as MnO2, PbO2.

garage chemist - 5-2-2007 at 15:18

I have also found a mix of Al (75 micron) and KClO3 (intimately mixed and finely ground) to be unignitable. This is very strange. I blame it on the oxide on the Al (though the Al is not old).
The KClO3 is good.
With magnesium, it forms a vicious flash powder.
A thermite mix, from the mentioned Al + red iron oxide, worked fine and burned very fast. It also was not too difficult to ignite. The oxide on the Al therefore can't really be that much.

quicksilver - 6-2-2007 at 06:35

You might try NOT using a large and volumous ignition source (torch) but making a trail of VERY FINE particulate on the edge of a piece of paper and lighting the paper with a match. -=Why=-? Becasue if you have a boarderline ignition situation the torch using the existing O from the air and the oxidizer many need to be fine particles to light up.....plus, you can see the sensitivity better with a lighter ignition source.....just a thought.

flash powder revisited

chemrox - 8-2-2007 at 22:09

Quote:

By volume: potassium permanganate 2 parts, Aluminium powder (the finest flour-like grade) 1 part, powdered sulphur 0.5 part.

To prepare, grind the KMnO4 to the finest possible powder in a mortar. You know when you've ground it enough when it changes in colour from dark purple to a lighter purple.
Clean the mortar then mix the Al powder and sulphur together.
Finally add the KMnO4 and mix gently, do NOT grind!

Add a drop of glycerine.

This is part of an old post. Do you suppose powdered Zn could be subbed for the Al?

hashashan - 9-2-2007 at 05:13

yes it is possible i have dont this couple of times. however this flash will be less energetic but with a light green color

feacetech - 12-2-2007 at 16:53

Quote:

This is part of an old post. Do you suppose powdered Zn could be subbed for the Al?

Yes it can and it works great you must change the ratio I have tried a few. The best ones that I have seen are 3:5:1, 4:5:1, 6:8:1 and 3:6:1 it is still a work in progress (KMnO4:Zn:S by weight of course)

I used fine powdered zinc from BDH flowers of sulphur passed through a 106um sieve and KMnO4 in the form of condys crystalls powdered in a mortar and pestal and passed through a 106umsieve

3:2:1 with zinc wasnt very good

but if your planning on giving it a go contribute to my trial and do some ratios that I havnt tried yet

http://www.roguesci.org/theforum/showthread.php?t=6055

[Edited on 13-2-2007 by feacetech]

Zinc - 1-4-2007 at 02:01

Yesterday I ignited a small amount of a mixture containing Fe powder, KMnO4, S and KIO3.
The mixture doesnt burn very fast but there is one interesting thing. The smoke is at first purple, then after around 2 seconds it turns brown and then white. Then I made the mixture again and ignited it to be sure that the collor changes really happen.
Does anyone know why it happens?

quicksilver - 2-4-2007 at 14:27

Unknowns include intimacy of mixture and particle size. but I would bet that the KMnO4 is your purple, etc.

Zinc - 3-4-2007 at 05:03

Quote:

Originally posted by quicksilver
Unknowns include intimacy of mixture and particle size.

The mixture was mixed for a few minutes in a mortar and pestelle. The KMnO4 and KIO3 were ground together and then iron (I got it from school. It is a fine dark gray powder. On the bottle writes that it is flammable. I do not know the mesh number) and sulfur were added. I dont know the ratios because I didnt weight the ingridients. I belive I added one third of KMnO4 of a part of KIO3. Then to that I added iron and sulfur until it felt right.

Zinc - 4-4-2007 at 03:24

How about C2Cl6 and Al?

Levi - 4-4-2007 at 03:29

Quote:

Originally posted by quicksilver
Unknowns include intimacy of mixture and particle size. but I would bet that the KMnO4 is your purple, etc.

Um, I think iodine is responsible for the purple.

Quote:

From wikipedia
Iodine is a dark-gray/purple-black solid that sublimes at standard temperatures into a purple-pink gas that has an irritating odor.

http://en.wikipedia.org/wiki/Iodine#Notable_characteristics

Zinc - 4-4-2007 at 04:38

Quote:

Originally posted by Levi
Um, I think iodine is responsible for the purple.

I thought that may be because when I lighted a mixture of KIO3 and S it evolved purple smoke.
But why does the smoke change collor?
I belive that iodine reacts with something that is also in the smoke. With what?

quicksilver - 4-4-2007 at 05:33

Ha...believe it or not I missed that... (I should never respond to stuff without morning coffee) I also miss my rolling eyes icon...

Zinc - 14-4-2007 at 06:28

I have read somewhere that MnO2 can be added to chlorate based flash powder to increase burn rate. Is this true? If yes how much MnO2 should be added? I think not much because supposedly it is a catalyst. I know that MnO2 is used in the laboratory preperations of oxygen. It is used as a catalyst for the termal decomposition of KClO3 to O2 and KCl.

UnintentionalChaos - 14-4-2007 at 09:14

You'd have to find a balance between providing decent catalytic action in a solid state and thinning out the flash too far. I would not add it until the last moment either, because by adding it, I imagine that the mix becomes significantly more sensetive.

Zinc - 22-4-2007 at 09:38

Quote:

Originally posted by Zinc
Yesterday I ignited a small amount of a mixture containing Fe powder, KMnO4, S and KIO3.
The mixture doesnt burn very fast but there is one interesting thing. The smoke is at first purple, then after around 2 seconds it turns brown and then white.

Today I tried it whitout KMnO4. The mixture burned slower and the smoke was purple but it didn't change in collor.

Zinc - 23-4-2007 at 08:46

A few minutes ago I ignited a small amount of a mixture of KClO3 S and Fe powder. It burns fast with an orange flame. I don't know what is the mesh number of the Fe powder but it is very fine. Unfortunately the mixture is unstable and can ignite whitout any apparent reason because it contains a chlorate and sulfur.

DeAdFX - 23-4-2007 at 10:39

Quote:

Originally posted by Zinc

Quote:

Originally posted by Levi
Um, I think iodine is responsible for the purple.

Well then... the smoke probably isn't purple colored but the reaction mixture is emitting purple light. The light hits the smoke reflecting purple light.

Zinc - 23-4-2007 at 10:47

I dont think so because the smoke changed collor after the mixture already burned (a second or two). If you have the chemicals try it. It is very nice.

209 - 24-4-2007 at 09:54

WOW!! Cool, that flash looks great. I'm curious though - Is this mix shock sencitive? If so, how bad is it? Safe enough to carry around??

209 - 24-4-2007 at 09:55

WOW!! Cool, that flash looks great. I'm curious though - Is this mix shock sencitive? If so, how bad is it? Safe enough to carry around??

Zinc - 24-4-2007 at 10:16

Yes the mix is shock sensitive and unstable. It can ignite whitout any apparent reason (it contains permanganate and sulfur). It is not safe to store it or carry it around. Make only small amounts and use it immediately after you make it. Don't use it confined in some container because it can ignite whitout any apparent reason. Also don't grind the chemicals together because it can ignite.

209 - 24-4-2007 at 18:47

maybe if you were to leave out the sulfer (im not sure that it acutally does anything) I am sure that it would improve the stability. Pechlorates, clorates and permangates should never be mixed with sulfer in the first place, why should they be mixed here?? Anyway, the mix cant be any worse than AP

12AX7 - 24-4-2007 at 20:26

Perchlorates [sic] are safe with sulfur.

quicksilver - 25-4-2007 at 06:05

The idiosyncratic element of mixing sulfur and KCLO3 is not dangerous in and of of itself.The concept is that moisture would evolve an acid if the sulfur had impurities...it is the acidic impurities in any KCLO3 composition that presents a problem. Sulfur being a classical example of an element with many impurities, etc. due to the old-time practice of using sulfur "flowers" (big difference).
With sulfur GENERALLY being as pure as most anything can be these days (sulfur "flour" of course) this is not considered a problem by many but rather it is a sensitizing agent when speaking of a composition that is to be considered for shock or friction sensitivity.
One can try this typical PGII experiment at home. Mix a 70/30 flash mix with KCLO3 and the finest grade Al available. Test via slight enclosure for response to flame.....you will get a sharp report. It's loud. Then place a small amount on an iron surface and strike it with a hammer.....no report! Sensitive with sulfur to a 3:1:1 level (at one gram only, don't make a large amount) - strike with hammer and you'll have a strong report (close to flame stimulus). Hell, the composition seems like a primary HE, it's so sensitive to shock and powerful. If the material is kept dry and not exposed to stimulus it won't explode however. But it DOES make an interesting display.

Zinc - 30-4-2007 at 06:15

Quote:

Originally posted by 209
maybe if you were to leave out the sulfer (im not sure that it acutally does anything)

Today I tried it whitout sulfur. It burns slower with a orange flame and white smoke. The smoke doesn't change in collor.

quicksilver - 1-5-2007 at 05:46

IT IS GENERALLY AGREED THAT SULFUR WILL LOWER THE TEMP NECESSARY FOR IGNITION in compositions where it functions as both a fuel and reducing agent.

.50AE - 7-7-2007 at 06:12

Hello everyone,

I'm new to the pyrotechnics, and my first try is the flash powder.
I use KMnO4 + Al, but no sulfur, beacause i'm worried that it will be unstable, like I have read in other pyro web sites. But still, i'm not sure about it, will it be safe ? I don't store the powder more than 2 days, I make it and I immediately use it after this.
I'm using this flash powder for home made firecrackers made from paperboard. The question is - can the firecracker explode spontaneously im my pocket or hand ? Should I be worried ?

The aluminium powder is 400 mesh, the KMnO4 too.
I'm sorry if my english is bad. Thank you.

[Edited on 7-7-2007 by .50AE]

[Edited on 7-7-2007 by .50AE]

quicksilver - 7-7-2007 at 06:26

YES -> YESYESYESYESYESYESYESYESYESYESYESYESYESYESYES (see how you can see the word "EYES" even though it's not there?)

YES, you should be worried, very worried. Virtually all of the real nasty (& I mean nasty) accidents that happen to first time / new pyro experimenters happen via flash. And using KMnO4 for your oxidizer is asking for it. Do NOT do this experiment. --- Instead, try making standard flash in quantities of LESS than 1 gram!!!! - and work with that for awhile. If you should have an accident you most likely won't loose sight in both eyes and I think that one gram of good strong flash in a paper enclosure won't knock more than one finger off and if it's not your thumb, your still in the game!

However on a serious note, energetic compositions do need some stimulus to initiate but the mere fact that you are asking that question indicates that you should research the various methods that initiation may occur BEFORE you even open a bottle. Quite frankly questions like this make me generally want to convince the questioner that the project needs much more information prior to the actual lab. Some folks think that it's the material per se' that gets them in trouble; but it's really lack of knowledge that does them in.

So a search on 'accidents", "serious injuries", and "nightmare" before you start....it will give you an opportunity to re-think your first project. How about a cone or a sparkler? They can be fun and they won't disturb the neighbors.

Now, I don't want to put you off pyrotechnics in any way.....I really don't. But pyro is much more fun with all your body parts! Especially that part about you putting it in your pocket......You WILL want to keep your genitals: honest! Whats more, a tearing, searing burn to one's scrotum or penis is very bad form to present to the hospital. Circumcision through traumatic amputation is also bad form.....the penis is a terrible thing to waste.

[Edited on 7-7-2007 by quicksilver]

.50AE - 7-7-2007 at 06:34

Well, I have already made many times this flash composition in 1g to 15g, but ignited it unsealed. I tried many times to hit a 0.2g mixture, but i did not ignite.

By now, I've never had an accident, or spontaneous explosion. Thank you for your reply

.50AE - 7-7-2007 at 08:09

Thank you very much for the post.
Well, i know how a blown hand, or head looks like and I really don't want this to happen to me

. I don't want to become a professional pyro technician, I just want to make some beginner's stuff, like small firecrackers, smoke bombs, fountains and maybe rockets later.
But I must be sure that they are safe enough first. If not, I won't make them.
What I like at the KMnO4 flash powder is that it produces a very beautifull flash, is powerfull, simple to make and the potassium permanganate is very easy to find. For now, i've never had a problem with stability, but thank you letting me know. I always mix small quantities, so there should not be a problem. And maybe when i want to explode a firecracker, i'll put the flash powder and seal it just before I ignite it, maybe it will be the safest way.

[Edited on 7-7-2007 by .50AE]

DerAlte - 7-7-2007 at 22:53

@ .50AE - heed the wise advice in this thread.

I am not a pyrotechnician but do not disapprove of them in any way, let me add. I only hope that any who indulge know the risks, both to themselves and to others. Responsible amateurs do. I used to dabble in it myself, more years ago than I care to remember. I still do the occasional energetic reaction for grandchildren.

That said, I think you have the correct cautious approach. This is an old thread I had nor seen before since I am also a new member. I was previously reluctant to mention my experiences with KMnO4 and flash powder but I see it has come up before, so here's my 2 cents worth. Don't want to excite the kewls and teenies!

My first flash and actual explosion was with the KMnO4/Mg mixture mentioned above (early teen years). I had by then tried chlorate (didn't have perchlorate) and Al, Mg, S, C - any reducing agent I knew and had, in fact, including red P. Chlorate and red P I had found was a no-no, having managed to burn off eyebrows and eyelashes by trying to mix in a mortar. Luckily no eye damage, it burned (relatively) slowly. Sulphur and chlorate could explode under a hammer, but the flash powder only went whoosh or pop in a short tube. Comparing chlorate to KMnO4 on a paper strip, I was amazed to find that it was faster. Tests in the same sized short tube actually made a crack. Being a bright young lad, even if deficient in knowledge, I later added some sulphur, thinking that for a really good explosion a bit of gas would help.

It did. I also found that Al did almost as well but not quite, in spite of the fact that the Mg was granular and the Al very fine mesh. I made immunerable bangers and crackers in this way without any problems, but came to respect this mixture. A couple of years later, on firework night I made a rather large one, I guess about 30g, an ounce or so, and let it off in the middle of our lawn. It was in a carboard tube tightly bound with # 18 copper wire.

This was the first time any 'firework' had ever scared me. I felt the blast wave. My parents informed me it rattled the house windows. Early the next year I electrically detonated one about the same size within a 5 ft snowball rolled from the lawn. I can only describe the result as a muffled roar and an visible increase in the ball's size. Slicing into the core, (which I found to be beautifully stained red) I found the snow compacted into an icy center with a hole about 1/2 its diameter. I have often wondered since if this mixture is not detonatable - it is very potent.

My last experiment involved putting an even larger quantity in the fork of a tree on some waste land at night. It split the tree - bigger than a sapling - into two parts.

Much later I found out by reading that this mixture is dangerous if allowed to get damp, that chlorate and sulphur don't mix safely and a few other facts. Guess I was lucky. I never stored any mixture, always used it within an hour or so.

Blaster is right about grinding the KMnO4 as finely as possible for the 'best' results. But if you do it right, good old BP can give you a safer banger but without that crisp crack or the flash, of course. Confining a fast burning mixure often will give a bang. But, to my mind, It's hard to beat the permangante/ metal powder. But it is hazardous.

Regards,

DerAlte

tito-o-mac - 9-7-2007 at 07:25

Are all alumnium-based perchclorate stuff can be mixed and used to make rocket fuel?

quicksilver - 9-7-2007 at 09:51

Quote:

Originally posted by tito-o-mac
Are all alumnium-based perchclorate stuff can be mixed and used to make rocket fuel?

I not entirely sure of the question; however if you mean all materials that are perchlorates then the answer would be, no.

There are variables that would need to be addressed in all issues of propellant composition. Generalities of this nature are not a good idea. But I might add that ramming a perchlorate composition is not a good idea....

[Edited on 9-7-2007 by quicksilver]

rocket - 9-7-2007 at 23:23

If your asking whether Al/KClo4 can be use as a propellant then yes it can but I highly advise you not too. I have read that Flash powder has been used as propellant much like whistle is but the problem with using flash is it a lot more sensitive when pressed, don't even thick of ramming it.

Zinc - 18-7-2007 at 02:30

I know that this is off topic but I didn't want to start a new thread about that. I know that KMnO4 flashpowder is very unstable and that sulfur makes it even more unstable. Is a mixture of KMnO4, S and powdered charcoal more stable? Can it spontaneously ignite? Is it safer to use? I made that mixture two times. It doesn't burn very fast but it also doesn't burn very slow.

DeAdFX - 19-7-2007 at 10:12

Just stick with regular ol Black powder. In the field of pyrotechnics KMnO4 is only good for flash powder its mixes with fuels is less than useful.

gregxy - 19-7-2007 at 17:11

I made flash powder many times with KMnO4 or KClO3, Al
and S. I dont think that spontaneous combustion should be
a problem with small (gram sized) quantities. Most likely it
would slowly become inert, but I never saw this happen
even in material stored for months.

Friction is a bigger problem. Always grind the ingrediants
separately and the mix them using something soft like a
piece of paper or a rubber covered wire.

.50AE - 19-7-2007 at 20:45

Hello again

@DerAlte , Thank you for the nicely post.

I made some tests with KMnO4 mixtures, so I will report them here

.

First, I mixed KMnO4, Sugar, and Al powder (8:4:2). It is flash powder, plus some sugar. I added it to slow the combustion, so to lower the risk of serious accident, in case of self-ignition.

Next, I first tried to ignite it with a lighter, it was a little difficult, but it worked. After this, I put the rest of the mixture (3 grams) in my bathroom in a safe&open container, so there were no risk of fire.
One week has passed, I returned to the bathroom and I took the container with the mixture. It was hardened into a hard bloc, but no problem. I took the whole bloc of mixture from the container and I tried to ignite it with the same lighter again

The result was : Very easier ignition than before, that means much more fragile mixture.

Later, I tried another thing - I took a wooden stick and i started to grind the rest remaining quantity of the mixture in the container (~10mg).
The result was : Cracking sounds and sparks. That means the KMnO4 is igniting from friction, so be careful

The other day, I made 1g of fresh flash powder and I stored it for 5 days with the same way, the result was - very very easier ignition than the fresh mixture.
Beacause it was in a bathroom, i think the wet air decomposes the KMnO4, i'm not sure.

That's all, hope i've been helpful

.

So my advice is to do not store KMnO4 flash, or other mixtures. Use them immediately

.

[Edited on 20-7-2007 by .50AE]

[Edited on 20-7-2007 by .50AE]

[Edited on 20-7-2007 by .50AE]

rocket - 20-7-2007 at 01:29

What ever you do don't add sugar to a KMnO4 comp, if you add sugar to the comp it will make it water sensitive meaning when water comes in contact with it it will ignite. By putting the comp in the bathroom you made the risk of ignition even higher.

Its best just to mot use KMnO4 comps as the just to sensitive.

.50AE - 20-7-2007 at 06:46

I was doing some experiences with KMnO4, that's why I added sugar. Anyways, i'm not using this composition

By the way, the flash powder was igniting much easily after storing 5 days in the bathroom, so maybe the reaction from the wet is the same.

Zinc - 21-7-2007 at 06:05

I made a impact test with the KMnO4 black powder. I put too much fuel in it so it didn't burn as fast as a good mixture. I had to hit it strong with a hammer to ignite it and always only a part of the mixture ignited. I will try it agani with a good ratio mixture.

Zinc - 3-9-2007 at 10:12

Today I tried it. It burned faster. But not as the first 2 times I tried it long time ago (arond 1 year). That time my and my friend used homemade charcoal. Every mixture we made with that charcoal burned faster than the same mixture made with the bought. I didnt make any impact tests. Will report when I do.

Bert - 3-9-2007 at 12:30

Home made charcoal cooked for a shorter time and at lower temperatures than commercial has a reputation for making faster/more powerful black powder as well. The reason being retention of more volatiles, and a different structure than the longer/hotter cooked commercial product. Like the difference between coal and graphite- One burns, the other is a great refractory.

quicksilver - 3-9-2007 at 13:39

Coal, when reduced to single digit micron particles (like 9um - air float size) works quite well in some compositions due to it's density. What is interesting is that when speaking of BP there does appear to be a difference in origins of the charcoal [type].

I really don't remember who or what the specifics were but some pyrotechnic newsletter some years back had a demonstration of placing a 1/4 gram or KCLO3 and 1/8 gr (or less) of sulfur on an anvil and striking it w/ a hammer. It made a loud & impressive report for it's weight and simplicity, etc. Demonstrating the sensitivity of a simplistic composition & the need for safety w/ chlorates or some such deal. When the same was attempted w/ BP there was no report; even when attempted in various circumstances & conditions.

Squall - 3-9-2007 at 15:49

Has anyone tried making flash powder with magnalium instead of aluminum.

ordenblitz - 3-9-2007 at 18:37

Certainly.. works just fine with perchlorates..... or chlorates if your brave.

12AX7 - 3-9-2007 at 20:04

Meh, potassium chlorate hardly burns with it. If ignited suitably, sure, but why that should be necessary, I don't know. (Ooh, the opportunity for chemical curiosity!)

Tim

hashashan - 3-9-2007 at 21:53

I prefer to use Mg flashes, they are much more powerfull then Al

Bert - 4-9-2007 at 12:54

Mg flashes are not suitable for long term storage. Even unmixed Mg powder in contact with air will oxidize to uselessness rather quickly.

Mg/Al flash has more of the stability of Al based flash, and some of the speed of Mg based flash. Chinese commercial cylinder salutes made with Mg/Al 50:50 granular powder have been available in the US. The ones we've used were quite good.

vulture - 4-9-2007 at 13:09

ANY KMnO4/metal mixture is to be treated with respect and care. 1g quantities can blow off fingers and create dangerous shrapnel (speaking from experience here).

ordenblitz - 4-9-2007 at 21:59

Bert,

Really depends on where you are located. In my neck of the woods.. mag flashes will last for years and years.

hashashan,

I disagree that mag flashes are more powerful as that is a subjective term. Mag flashes are certainly easier to ignite and possibly burn faster but put out slightly less energy than aluminum or mg/al ones.

Just my opinion based on years and years making a living working with these types of reactions.

hashashan - 4-9-2007 at 22:46

Al is problematic gor me ... I can get only 325 granular Al here (the dark i should make myslef and didnt try yet). Mg however does make one hell of a flash when mixed with KClO3.
And regarding the storage.... I dont store it so i dont kow how stable it is. I dontsee a reason to store it.

Squall - 5-9-2007 at 16:53

I remmeber about a year ago when i had some KMnO4 i took some flint and carefully filed it until i had just a pinch(this is actually very hard to do because a minor spark will catch it on fire and you have to start all over) I mixed the flint with KMnO4 and what i got was an amazingly powerful flash powder probably not very practical but very strong. just wondering if anyone else has tried this.

DerAlte - 5-9-2007 at 19:26

You can buy cerium metal reasonably easily - lighter flints are cerium and iron.
Read a few pyrotechnic sites for ideas - but be careful, always.

Regards, Der Alte

Mumbles - 17-9-2007 at 21:40

I do believe you will encounter some relative difficulty preparing your own dark aluminum. Believe it or not, but 325 mesh Al ball milled with lead until it is dark with contamination isn't quite what you'd expect to get from Eckhart.

hashashan - 17-9-2007 at 23:34

How about steel media?

Mumbles - 18-9-2007 at 07:46

I'd suggest going and doing some reading about the processes that go into manufacturing dark aluminum. And no, steel media isn't going to give you dark aluminum either.

nitro-genes - 18-9-2007 at 10:01

Errrr, I've made my own dark flake aluminium for years before the commercial stuff became available to me. Just an airtight rocktumbler filled half with 1 cm diameter steel balls. Took about 5-7 days to go from shredded aluminium foil to a dark grey powder, which performed just as well as dark german, meaning 100 mg's 7/3 Kperc/Al on the tip of a knife making a distinct and loud POEMP sound with white flash flash upon ignition. Compared to the commercial stuff I have now I see little difference, other that it safes a lot of effort to simply buy it. Without screening there is some larger fractions of particles left, creating longer lasting white sparks, but even with the commercial stuff you occasionally see this. Maybe the oxide percentage is somewhat higher as well, but it is definitely not impossible....

Why making two single-lined posts about what ain't possible, if you could have made 1 post with at least some clues or directions where to look?!

[Edited on by nitro-genes]

Mumbles - 18-9-2007 at 21:45

Dark aluminum, simply put, is not prepared by just ball milling it. Dark Aluminum has some carbon and other things coating it's surface to prevent an oxide layer of the normal extend from forming. Dark color does not neccesarily equate to dark aluminum. In the size and shape it is in, the oxide layer would consume a great deal of the particles. As I am aware, the aluminum stock is rolled into a thin foil, and glued to some thin paper. This is then shreded by mechanical means, stamp milling I do believe. The paper is then burned off in an inert atmosphere, giving the characteristic dark color from a bit of carbon being left over. There is some speculation of aluminum carbide being formed, and increasing reactivity at this point, but I have seen no real evidence proving this. It is probably then reduced again by stamp milling or ball milling.

So, dark aluminum involves integrating carbon into the outside layer. Simply ball milling until it is pitted and oxidised appearing dark will not give an equal product in my opinion.

nitro-genes - 19-9-2007 at 06:14

It is a common misconception that all grades of dark aluminium go through the roasting process. I saw a photo once of one of the fastest grades of Eckhart dark aluminium and I can say it looked exactly like the stuff that came out of my ballmill. Not like the german black aluminiums, but rather a dark grey with blueish appearance due to the lack of carbon. IIRC, Shimizu's himself mentions in some of his books that dark aluminium can be made by ballmilling coarse aluminium powder with 5% oil to reduce oxide formation. An airtight milling drum is a necessity, else you will indeed find only some oxide left after a week of milling. I read once that even the best grades of dark german aluminium can contain up to 20% oxide/inerts, so this probably something that is inevitable with decreasing particle size, unless some special coatings are aplied like for alex...

[Edited on by nitro-genes]

Mumbles - 19-9-2007 at 09:48

He was discussing flash, and that generally makes me automatically go to the blackhead types. A dark aluminum, something like 809, doesn't result in nearly as strong of a flash as the finer materials. I would think that addition of oil before the milling would result in more of a bright flake Al. Perhaps the stearic acid used in the bright flake I am familiar with has some other sort of property that prevents it from darkening, or is made in a different process. I would imagine stamp milling would be more often used, as it should be more efficient in this type of process.

The drums of the blackhead Al (Ekhart 5413-H) I've seen are something like >94% Al <2% Carbon <2% Al2O3 <2% Stearic Acid

Really what I was trying to say is that just because an aluminum is dark in color, doesn't neccesarily make it a true dark aluminum and suitible for flash powder or other uses that require fine flake material. Dark from roasting or wrinkles/scratches/etc is definatly different than dark because theres a considerable amount of lead or oxides in there.

quicksilver - 20-9-2007 at 06:47

I am aware of a grade of India Black that unquestionably had a share of carbon in it. A PGII writer did a little piece on dark Al and found that some had as much as 12% carbon and that some had additional C added as an adulterant. There was a grade of India black that was considered as a "rip-off" due to the level of carbon present sold by a large pyro supplier some years back. In the older posts I have the names and details of this whole issue.

I too have made a respectable grade of dark using Tank or Tractor ball bearings (1.25") in a rock tumbler turned ball mill but my starting material was Alcan 808 @325. Tumbling time was 48 hours and I had a dark that was better than most I have seen sold. It was attempted twice again with two pounds and larger starting Al. I shy away from foil due to the coating, etc. But I have used simple floor shavings that were ridiculously large and mostly granulated. I imagine foil could work if it was determined to be uncoated, etc. Even if it was coated the material may not be such a big deal as there has been Al sold in the past with Teflon in it and it was unusually reactive.

Same time and I had some very, very fine Al. Similar to 5413, this material was very good. In that I maintained this for about two weeks as I had a lot of floor sweepings and the price was right (free). Due to the make-up of my medium I had flake of course. I also tried this with spherical Al and received high grade flake from that as well.

.50AE - 30-9-2007 at 04:26

This summer i made many flash powder salutes using KMnO4, Aluminium and sulfur (6:2:2). I think if you handle it carefully and you do not store it, you should be fine. The powder was very powerful. I also tried to place 4gr of this flash in an open plastic vitamin container. The ignition resulted as a nice bang (like gun) and a big and beatifull flame from the hole. The tube was intact, and i was been able to use it many times.

The sulfur I used was a high purity one, I bough it from my local pharmacy.

Here's a clip of 8g powder http://www.youtube.com/watch?v=olwzirU-qso

[Edited on 20-07-2007 by .50AE]

Formatik - 16-7-2008 at 02:24

Here's one without metal powders. 2 vol. parts KClO3 and 1 vol. of gallic acid (O.B. precise 74.24% KClO3 and 25.76% gallic acid, %by mass). This mixture decomposes immediately on flame contact about as quickly as flash powders unconfined, but there is little flash and a lot of smoke. It is also very friction sensitive.

TechnologicallyRetarded - 15-8-2009 at 01:07

As with very early posts, I too am unhappy with my Aluminium. It was bought from Ebay however - so I was not expecting miracles - but it's odd...

It looks very fine, but I have no mesh size for it. It looks very pale and not dark at all - I presume it is atomised with a level of oxidation. With NaOH it liberates Hydrogen fairly rapidly, though this would be expected of even heavily oxidised Aluminium. And Thermite seems fine with it.

However, with Chlorate and a trace (Please don't eat me anyone) of Sulfur - zilch.

In short I'd be interested at milling my own. From quicksilver I gather that tractor bearings make ideal milling media, but what about the container we are grinding it in? Stainless steel? Also, what should they be coated with/should antioxidants be added?

Tr

quicksilver - 21-8-2009 at 07:04

The medium should be offset by the container....If it's steel, then the container should be rubber like a rock tumbler - if it's ferric, use lead as your tumbler medium. Just be wary of spark production - no big deal. I have made some DAMN fine Al with a rock tumbler and some cheap heavy shot; starting with some aluminum foil cut into strips and placed into a blender first to get it reduced down....
Depending upon the size of the devices; pounds at a time!

1281371269 - 3-10-2009 at 10:09

I had a friend round today and made the mistake of showing him my lab. He would have been bored to death by the thing I wanted to do (redistill the ethanol I have collected) and so I thought I'd try to prove there were exciting things too by making some of the flash powder given in the first post of this thread. I made about 20g in total. We set off a few .5g amounts which made nice flashes with a small 'whoosh' sound. I noticed however that glycerine wasn't really setting it off - uncontained it didn't at all, and when I used a tiny plastic container it took a good 45s. After a few such flashes we took the remaining 18g or so, put it in a small glass container on some bricks next to a wall, placed some bags of earth around it, added a ml of glycerin on top, screwed on the lid and went about 10m back. After a tense minute, nothing, after two, still nothing...two and a half, nothing. I assumed it hadn't worked for whatever reason so avoiding the container we went back inside for about a minute to collect the equipment that needed washing. Just as we turned to leave, 'BANG', a huge flash, and the sounds of bits of glass smashing to the floor.

There was no real safety threat, we had goggles / gloves on and the glass didn't travel far. But it was one hell of a shock.

My question is: Why so long? When I put glycerine on KMnO4 normally it lights in about 15 seconds, so why now were the drops taking ages or even failing to set it off?

densest - 3-10-2009 at 17:00

I'm going to be my usual safety nagger here: when ball milling reactive metals, if your mill jar is too well sealed, you may get a catastrophic ignition when you open it. The man who wrote the book on amateur ball milling got a near-fatal sunburn from milling magnesium & opening it - the flame was hot enough to radiate huge quantities of ultraviolet light. His skin never fully recovered and luckily he wore safety glasses or he would have been instantly and permanently blinded.

Other than that this looks like fun

as long as one respects flash powder. Most of the fireworks factory explosions in the news result from multi Kg of flash powder accidentally ignited. "Good" flash powder will go supersonic (make a bang) in an open pile of somewhere around 1 gram or less...

hodges - 3-10-2009 at 18:41

Quote: Originally posted by Mossydie

My question is: Why so long? When I put glycerine on KMnO4 normally it lights in about 15 seconds, so why now were the drops taking ages or even failing to set it off?

Two big factors are the water content of the glycerine, and the temperature of the air. Add a drop of two of water to you glycerine and it will work much faster, unless the temperature is really cold.

Hodges

argyrium - 4-10-2009 at 12:04

Regarding slow rxn of the Al/KMnO4 and glycerin, if you are using flake Al, it will very likely "coat" the KMnO4 and somewhat isolate the contact w/ the glycerin. A small addition of EtOH or other low viscosity polar solvent should speed things up. Please do test before scaling-up.

As previously mentioned by others, KMnO4 is an unpredictable oxidizer and has maimed many experimenting w/ it. Better to stick to the tried-and-true standard ones; safer/ more predictable.

Best!

1281371269 - 5-10-2009 at 11:46

My Al is Ekhart German Dark powder, so really top notch. But yes it is flake.

On the the plus side, KMnO4 is easy to get hold of (something to do with fish tank cleaning) and it means I don't have to use my equally unreliable fuse. It's a KNO3 / sugar one and burns well but sometimes just stops, unpredictably. I think I need three strands braided together to prevent this.

Maimed? It would need a pretty huge amount to do much damage surely? - even if I had been right next to the bit I set off, I think the danger would have been the glass flying rather than the explosion itself.

Zinc - 15-10-2009 at 05:30

For those that can't buy Al powder, it can be obtained from paint. Just dilute the Al paint with paint thinner (approx. 1 par paint to 5-6 parts of thinner), wait a few days so that most of the Al settles to the bottom of the container (most will settle, the finest particles could take more than a week to settle). When the Al settled suction of the liquid (be careful doing that so that the powder doesn't get disturbed and floats back in the liquid) and add again some thinner (don't know how much exactly because I haven't measured the amount, but less than the 1:5 ratio) and again wait for the Al to settle. I repeated the process three times to remove most of the organic material from the Al. When the last step is finished suction of the liquid and let the Al to dry.

The Al powder obtained this way works good when mixed with KMnO4 (even with out sulphur), but I don't know how safe is to mix it with KMnO4 as some organic material will remain on the Al and that could cause it to be unsafe (perhaps even to self ignite). I never stored the mixture, and only used it a few times for small salutes.

Perhaps It would be easier to just dilute the paint with thinner, filter out the Al and wash it with some solvent but as the Al is quite fine it could cause problems with filtering if fine filter paper and vacuum filtration is not used. Using filtration and washing would also remove much more organic material from the Al so it would be much more safer to use for various pyrotechnic mixtures.

Also zinc can be extracted the same way from zinc-containing paint.

[Edited on 15-10-2009 by Zinc]

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