823 replies to this topic

[BrightStar]

hi i know its no good for flash,but atomised ali powder how do they "atomise" it at the factory,any body know the process

A few details here:

Manufacture of Metal Powders - http://www.mpif.org/apmi/doc4.htm

Edited by BrightStar, 04 June 2007 - 07:37 PM.

[rocket boy]

A few details here:

Manufacture of Metal Powders - http://www.mpif.org/apmi/doc4.htm

Im under the impression that the aluminum is melted from a wire spool that is fed into a die and is melted using electricity or a flame and then it is pased thru a jet that has high pressure air or a gas and is sprayed into the air forming small balls of aluminum (atomized) which falls back into a collector which produces the aluminum. Thats the basic info that I have on the subject...Rocket boy.

[cooperman435]

Basically atomized powders are made by the same principle as aerosol cans where the tiny droplets of metal are allowed to cool before touching anything and remain as a powder.

[portfire]

I cant figure out why your doing this ,are you going to post something or what

[karlfoxman]

Hmm havent seen this, but now no one will as they are pointless so there going!

[Anubis386]

Being reletively new to pyro theres no way i'm even gunner attempt perchlorate flash but I am experimenting with Pottasium Nitrate Flash -

Pottasium Nitrate - 60
Aluminium - 30
Sulphur - 10

I found the mixture on the PyroGuide wiki ... and i'm trying it with different metals .. magnalium works very well and i've got some flake al and dark german al to try at some point ...

The confinment of my small rockets produces one hell of a bang!

[MDH]

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Edited by MDH, 16 April 2008 - 09:33 PM.

[parabolic]

Does anyone have an idea of what might be flashpowder's flash point temperature?

just that I have been looking at some comercially made maroons that contain 100grams of flashpowder and an ematch to fire, but when looking at how the cardboard end plugs/caps were fixed to the main cardboard marron body, they are HOT melt glued on both ends.
I can under stand hot glueing one end, when there is no flash in the maroon, but hot glueing the other after it is filled with flash sounds insane and makes me think what whacko made the maroons!

para

[Asteroid]

Hot melt glue is around 120*C normally, and all I can think of with a flash point that low are hydrocarbons.

[MDH]

Parabolic, there are low tempature hot melt guns out there!

Flash can ignite at lower tempatures but generally speaking without a great input of energy it's not likely to combust through a basic thermal source without at least a tempature of around 120 celcius (at a practical most, around 1200 celcius). Of course it's better to be safe in the longrun but I don't think hot glue is likely to do much unless you are using a very hot glue gun.

I know mine heats to 90 celcius at most.

And, Of course, it depends on which flash you are using.

Edited by MDH, 04 July 2007 - 08:38 PM.

[Creepin_pyro]

but when looking at how the cardboard end plugs/caps were fixed to the main cardboard marron body, they are HOT melt glued on both ends.

Just wondering how you can tell whether it's hot melt glue or any other type of glue?

Do a REC.PYRO search for glue gun - there are some interesting discussions about the dangers of using them around live compositions. They can fail catastrophically, and while the glue itself is unlikely to ignite most comps, it's a good idea to unplug the gun before using it to eliminate the possibility of an electrical fault. I do avoid using hot melt though, for these reasons.

Edited by Creepin_pyro, 04 July 2007 - 10:29 PM.

[BrightStar]

Does anyone have an idea of what might be flashpowder's flash point temperature?

My guess is that for standard 70/30 it is fairly high. The perchlorate will not start to break down before 500 centigrade and I can't see the aluminium being much lower. You only need a very small region of high temperature however to ignite it. In a normal ignition flame you will have a spread of flame temperatures, so you can usually (but not always) ignite 70/30 flash with unprimed visco.

Adding sulfur will bring the ignition temp down to nearer 300C, using chlorates or sulfides will bring it even lower, perhaps nearer 200C.

Would I use a good quality, low-temp glue gun to seal a small 70/30 filled crosette? Yes. A larger salute / maroon? No, but then I never make them anyway

Edited by BrightStar, 05 July 2007 - 07:30 AM.

[MDH]

BrightStar:

Potassium Perchlorate, 60
Dark Aluminum, 25
Antinomy Trisulfide, 15

I don't remember where I read it, but I'm sure that flash will ignite at below 200 celcius.

Frankly I don't like pure flash as it makes stars rather hard to ignite, but if you are just going for a bang, the above is one of the fastest recorded compositions (I believe it is one of the greatly debated "detonaters").

Edited by MDH, 05 July 2007 - 05:25 AM.

[Wyvern]

BrightStar:

Potassium Perchlorate, 60
Dark Aluminum, 25
Antinomy Trisulfide, 15

I don't remember where I read it, but I'm sure that flash will ignite at below 200 celcius.

Frankly I don't like pure flash as it makes stars rather hard to ignite, but if you are just going for a bang, the above is one of the fastest recorded compositions (I believe it is one of the greatly debated "detonaters").

That is close the comp i use for my crossettes, basicly switching the parts from the Al and trisulphide and can comfirm this stuff is incredibly easy to light and burns very fast hence i only make a maximum of 2-3g at a time, also ill add i would recommend not putting this directly inside a crossette but making a mini "salute" to fit inside the cavity.

[rocket boy]

Alright, yes flash powder is and should be a sensitive topic, but I haven't really seen anybody hit the subject that directly on this forum, so I feel that I should start up the questions and answers.
Alright, first off, I know that flash powders are to be used only in small amounts, perhaps larger amounts in mortors, but what are good formulas for specific flashes?
I have found several, but I think I'll ask if I can share them online before I actually do?
until my next response,
-mini
by the way, I was reading a post about BP growing white stuff, and you guys referring to it as 'mould'. Do you guys really spell 'mold' that way? I was confused, and thought it was pronounced "mowld". Hmm. That's all I wanted to say...

I've been making fireworks for years and my favorite mix for flash powder is ..75% potassium perchlorate, 25 % sulfur, and 25% dark pyro aluminum. In grams....potassium perchlorate, 340 grams, sulfur, 113.3grams, and aluminum, 113.3 grams. Mix the potassium and sulfur first and screen it about three times to mix it well. Then add the aluminum folding it without creating too much dust first then screen it being carefull not to create any friction (no scraping on any surfaces on your mixing containers). Getting the blend nice and smooth and free flowing I then spoon it into a mustard type squeeze bottle that has a tapered tip on the cap and you have a way of putting the mix into the different paper tubes squeezing the bottle to push the mix out and stopping it for the amount needed in the tube allowing enough space for a glue ring all the way around the inside diameter of the tube then push a paper cap in flush to seal it. Most squeeze bottles come with some sort of plastic cap on them for sealing and you have a nice storage container and applicator for loading your tubes no matter how small or how large they are. Rocket Boy

THIS IS NOT THE WAY TO DO IT, FOLLOW IT AND YOU CHANCE OF DEATH OR INJURY ARE HIGH!! - Karlfoxman

Edited by karlfoxman, 05 July 2007 - 02:19 PM.