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Posted

Back in the day when I was visiting Blindreeper he had some Ba sulfate from a pH tester kit and some very fine Mg powder from...I think it was Static Firefly or someone who purchased it commercially.

 

Anyway, we made the flash powder (rough ratio, wouldn't have been 1/1) and it was the best of a fair few mixes we tried. They included KNO3, KMnO4 and KClO3 I think. We only tested them in open air, but the sulfate had by far the most output of light, gas and sound. Also, a hammer on concrete wouldn't set the powder off, but don't take my word for it, hammer tests always have very mixed reports. Same goes for the actual flash.

Posted

Wow the rumours are true!

Al, please do get a video of this as im pretty much skint at the moment so cant test that much. Would you be able to see if it can be ignited by bare visco (general ignition temperature and ease).

ceramics suppliers huhn?

Id assume they use it for there glazes or something? I tried lookin on the internet for some UK based ceramic suppliers but no luck- thanks for the idea i think i'll try lookin in the phonebook.

Posted

You could always buy a chunk of Barite and grind it up.

 

Worked for me with Celestite (Strontium Sulphate) : )

Posted

Eh, what about Ammonium Perchlorate + Aluminium

 

The commercial shit they use in flashbangs?

 

I have yet to try to make flash powder. I tried Kno3/Al/S but that way to slow and crap.. Kno3/400mesh-AL doesnt even light up with a sparkler.

 

From what people have been telling me outside the forum is that KMnO4 based flash is the strongest, and Barium nitrate based flash would be one of the brightest.

Posted
Well kmno4 is strong but not the safest, Probs barium and kclo4 compostions are the best to try.
Posted
Well the AL I bought is 625 mesh and I was talking to mumbles and he said shperical wont work. Has anyone tried anywhere close to 625 spherical with kclo4? 70/30
Posted

Buying barite eh? where did you manage to find a barium ore?? :blink:

400 mesh aluminium is pretty crap with alot of the oxidisers i use, when i tried it with potassium perchlorate it failed to light whatever i do! But KMnO4 will pretty much work with most aluminiums i heard (obviously it'll need to be pretty fine Al- still less than 400mesh or something). its oxidising properties are strong but its kinda unstable and decomposes over time (not that anyone would store much KMnO4 flash anyway!) :D

Posted
I was doing a little demo at school since we started chemistry in my science class so I showed some kclo3 mg flash both really coarse mixed without a scale just by eye and about probably 2 grams it reached critical mass
Posted
Well the AL I bought is 625 mesh and I was talking to mumbles and he said shperical wont work. Has anyone tried anywhere close to 625 spherical with kclo4? 70/30

Spherical should work but mabye not as fast/well and if it doesn't you can turn it in to flake by ballmilling it or a good hand at mortar&pestle.

Posted
Spherical at that mesh would not work! Calculate the surface area for a flake shape, then using the same dimensions, calculate for a sphere. The surface/volume ratio is not quite the same....
Posted
I know you all think that KNO3/Al/S is shit, but i really recomend it to you if you have Al like 400~mesh. I mill my KNO3 with S in 55/20 for around 2hours ,then i mix it with another 25 parts of my ~400 Al. I carefully mix it and so... i have a really goood flash. It burns kinda slow,but when you make a salute with really good casing ,it makes a hell of a sound... i made some test with kmno4/al vs. kno3/al/s and in different conditions kno3/al/s was even louder!!! Although no stronger than kmno4/al,it is really stronger,but i say you people,kno3/al/s is sometimes even louder!! And it is really safe if you add boric acid to it, to reduce the reaction between KNO3/Al .
Posted
I know you all think that KNO3/Al/S is shit, but i really recomend it to you if you have Al like 400~mesh. I mill my KNO3 with S in 55/20 for around 2hours ,then i mix it with another 25 parts of my ~400 Al. I carefully mix it and so... i have a really goood flash. It burns kinda slow,but when you make a salute with really good casing ,it makes a hell of a sound... i made some test with kmno4/al vs. kno3/al/s and in different conditions kno3/al/s was even louder!!! Although no stronger than kmno4/al,it is really stronger,but i say you people,kno3/al/s is sometimes even louder!! And it is really safe if you add boric acid to it, to reduce the reaction between KNO3/Al .

Do you need thick end plugs for that mixture?

Posted
No,mainly i do my tubes really thick,endplugs are 6layered of kraft paper, you just need to glue them in really strong.
Posted
oo Besides that spherical I bought..canceled that and got from that great guy over at pyroaluminum.com gave me 2 free lbs
Posted

Just be careful with the KMnO4/Al and KNO3/Al/S mixes.

 

The Potassium Permanganate and aluminum mixes, while very strong, aren't very stable for long term storage. The advantage with KMnO4 is that it's a very powerful oxidizer, so it'll work nicely, even with lower grades of aluminum.

 

With KNO3, the issue you run into is that if you store it, it absorbs water. Also, the presence of sulfur is an issue. However, as someone else noted, Boric Acid will help take care of that problem.

 

If you happen to have powdered magnesium around, that works really, really well with KNO3, but you absolutely cannot store it, as Mg reacts with moisture, and the KNO3 draws moisture into the mix. Still interesting to work with.

 

Personally, I only work with KClO4/Al mixes, as they're very, very stable, and the risks of static discharge setting the mix off while you're making the mix is quite low. Also, I only had terrible results with spherical aluminum. It just doesn't have the surface area necessary, although with KMnO4, you might get some results, but nothing great.

 

Oh, and when mixing your powders, always use the diaper method (look it up if you don't know).

 

Lastly, a great resource of info is the rec.pyro newsgroup. You can browse it or search it using google here:

 

http://groups.google.com/group/rec.pyrotechnics?hl=en

Posted
The most powerful flash powders are those made with KMnO4. KMnO4 is a much more powerful oxidizer than KClO4 and KNO3, and slightly better than KClO3. I dont know what is going through your heads when you say KClO4 flash powders are more powerful, this is simply not true. KMnO4 decomposes more exothermically than KClO4 (this also makes it more sensitive) and its decomposition products catalyze its own decomposition. This means that not only will it release more energy as it decomposes, but the reaction will be faster. My KMnO4/MgAl flash self confines in any quantity larger than a tenth of a gram, while my KClO4 flash made with the same MgAl self confines in quantities slightly greater than half a gram. In a test of shattering power, 5g of each flash powder was placed in an M-80 style tube, and placed inside a brand new toilet paper roll. The KClO4 charge split the roll in half, and a small amount of TP was shredded. The KMnO4 charge completely vaporized the TP roll, filling my backyard with shreds no larger than a dime. KClO3/MgAl produced a similar result to the KMnO4/MgAl, but the explosion did not completely shred the roll, it sent large chunks flying outward at high speeds, a couple landed on the road on the other side of my house. These chunks had a volume of about 1in3. This test was repeated several times with the same result. KMnO4 flash is some powerful stuff. I wont get into the safey aspect, as this is a thread focused on the most powerful flash, not the best overall.
Posted

Good info ^, Much thanks for all your test results B)

 

But better to be safe than sorry, I'll stick with KCIO4

Posted

Even though KMnO4 is a very powerful oxidizer it really has no place in pyrotechnics. There is no reason at all to increase the danger in an already dangerous hobby.

 

I don't consider a KMnO4 based flash powder the best under any circumstances.

Posted
How hard is it to turn Spherical Al to Flake? Would mortar & pestle do the job?
Posted
Yes, but I am sure it would be one long hard job! In fact, almost not even worth trying. It would be best to ball mill the atomized al to a flake.
Posted
,May 13 2006, 06:35 AM] How hard is it to turn Spherical Al to Flake? Would mortar & pestle do the job?

More like ball mill. B)

Posted
Yer, I'm to lazy to make a ball mill. :(
Posted
,May 13 2006, 11:34 AM] Yer, I'm to lazy to make a ball mill. :(

You can buy one for under 80 bucks with lead balls and everything.

 

I think unitednuclear sells them.

Posted
Even though KMnO4 is a very powerful oxidizer it really has no place in pyrotechnics. There is no reason at all to increase the danger in an already dangerous hobby.

 

I don't consider a KMnO4 based flash powder the best under any circumstances.

It's not the best, but perhaps one of the most powerful, and definatley one of the most readily available. Chromates and Dichromates are more powerful oxidizers, but are even more dangerous (chromate ion toxicity, I believe a couple grams can kill a person).

Posted

Lead balls won't work when milling Al because the lead is softer than the Al and you will get lead contamination. You need to use media harder than the object you are milling, or your mill won't work very well.

 

Why use KMnO4 and make flashpowder even more sensetive than it already is?

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