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Author: Subject: Bronze powder in flash composition???
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[*] posted on 8-10-2008 at 06:45
Bronze powder in flash composition???


Last week I find 3 kg of 1,5 um bronze powder. I want to use it for flash composition but i dont find any test with bronze falsh powder...

I make some research and i find a metal powder mix where have bronze powder in. (bronze+zinc+aluminium) . The problem is that I dont find any ratio of this mix.

I go see the father of my friend who is a painter and he show me two different mix of this kind of mix. was write ( very flamable )on it.:D but no ratio of the mix:(

If you have idea of some mix, can be fun to give me some.



Sorry for my english, I come from québec...
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jokull
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[*] posted on 8-10-2008 at 07:44


You have to consider that Bronze is an alloy itself.
A common bronze is 88% Cu and 12% Sn.
If you got such powder correctly labeled you should find a code beginning with "UNS" and several numbers, those numbers are related to the composition of your alloy.
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[*] posted on 8-10-2008 at 07:51


Many flash-powders involve a metal that's easily oxidised (typically magnesium or aluminium) and a powerful oxidiser like a chlorate, perchlorate, nitrate, peroxide or sulphate. Several simple metal oxides can play the part of oxidiser too. The flash-action is due to the enormous amount of heat that's released when the oxides of these metals are being formed upon oxidation:

metal + oxidiser ---> metal oxide + by-product(s) + reaction heat

The heats of formation of the oxides of the metals that make up a typical bronze or brass (copper, tin, and zinc) aren't very high, so they're not the first choice for making flash-powder.

If you haven't access to the mentioned oxidisers, try dried drywall (wall filler). After oven-drying at 300 C or so, that contains mainly anhydrous calcium sulphate, an excellent oxidiser for aluminium and one that makes a flash-powder with magnesium powder. Calcium sulphate is roughly as powerful as potassium or sodium chlorate (but more easily available).

If you're looking to create big bangs, make sure you don't blow yourself up in the process: you wouldn't be the first to do so!!!
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[*] posted on 8-10-2008 at 09:36


Flash using CaSO4 isnt the easiest to ignite and the products, CaS mainly, release extremly poisonous H2S easily so care should be taken.
If you have no experience with explosives, as it sounds, dont experiment with flash powder, nasty stuff.
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[*] posted on 8-10-2008 at 10:14


Thanks

I have a lot of experience with flash powder with al atomised (8800 mesh) and i going to have 3 micro dark germain al powder in 2 week (better with chlorate and perchlorate).
But i wanna try new metal in flash composition, like : Mg, Ti or Zn.

I just try (Al/bronze) 50/50 mix and i put with a stable flash mix (50 kno3/30 sulfur/20 (Al/Bronze)) and that seem more like a powerful rocket fuel...
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[*] posted on 8-10-2008 at 14:46


Are you sure it's bronze powder, and not *bronzing* paint pigment? Bronzing powder is actually aluminum powder, and will work at the usual 7:3 or 8:3:1 ratios. :)
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[*] posted on 8-10-2008 at 15:04


I going to try only bronze powder tomorow and i gonna see want that going to give, but i am pretty sure that is pure bronze.
The mix that you talk is maby the mix of (bronze, al, zn)

i going to try with this stuff too.
I going to show you somme pic of this and try to calculate the power with my new invention
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[*] posted on 9-10-2008 at 01:56


Before you start try dissolving a sample in dil nitric acid. If it goes bluish its bronze if it stays colorless its bronzing powder.
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[*] posted on 9-10-2008 at 06:02


I don't have HNO3... hard to find in canada. But i get some H2SO4 from a car baterie. I need to purifie it to get 96% and put a NO3 donator in to get HNO3... very long just to try by this way. I think it is more easy to find ∆H from oxidation of al and cu, caculate the pressure of the explosion and if it is similar, it is bronzing powder and if it is different it is real bronze:D
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[*] posted on 9-10-2008 at 06:52


H2SO4 wouldnt work, copper doesnt dissolve in it readily...
Do you have NaOH? if so make a dil NaOH sol and add powder. Al bronzing powder should dissolve and produce H2, bronze would maybe bubble a tiny bit (becuas eof any zinc) and leave Cu powder (browny orangy powder)
Not easier, more danerous...
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[*] posted on 9-10-2008 at 07:42


NaOH can be possible to make with electrolist of NaCl:D
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[*] posted on 9-10-2008 at 07:49


True but you would need a membrane to stop the Cl2 reacting with it. There are loads of threads on this topic thought, UTFE!
It can be bought form pharmacys (eg. Boots, CoOp) and hardware stores as a common drain unblocker.
Common bleach contains small ammounts and i think this will be sufficient.
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[*] posted on 9-10-2008 at 10:37


Copper is attacked by HCl (even relatively dilute) in the presence of an excess of chloride (e.g. NaCl), albeit slowly. Fast enough though to get a positive reaction with powder almost immediately. Bronze should do it too.

Alternatively, if you have any soluble copper salt, you can test the powder for copper by reacting the copper with a Cu(II) salt solution in HCl, as described here by Woelen.

Concentrated sulfuric acid dissolves copper (with evolution of SO2, IIRW).
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[*] posted on 9-10-2008 at 10:56


Conc sulphuric does dissolve copper but only when heated whilst Al will dissolve in dil H2SO4 cold. Thata was the test i meant. HCl could be used.
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[*] posted on 9-10-2008 at 11:25


An even simpler method for testing for copper is to add the powder to a solution of HCl, to which some H2O2 is added. Even the plain 3% H2O2 works well, combined with 10% HCl. If there is copper, you get a green solution.

The link given above to my webpage is not really for testing for copper, because it is not specific. Any reducing metal will form the dark complex, due to formation of a mixed oxidation state complex. If your only task is to determine copper (or not), then use the HCl/H2O2 method. If no HCl is available, H2SO4/H2O2/NaCl also will do the trick.




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Want to wonder? Look at https://woelen.homescience.net
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[*] posted on 9-10-2008 at 16:49


I make the test and it is cupper:(...
i try in flash and that burn very slowly... i think that bronze powder it not made for flash powder...
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[*] posted on 10-10-2008 at 02:16


Flash powder is basically where a maetal is oxidised by an oxidising aget and the energy released during the oxidation comes out in the form of heat energy, light energy ect...
becuase of this powerfull flash powders use metals easily oxidised, eg. Mg, Al ect...
As i am sure (hope) you know Cu is hard to oxidise so it is bad in flash powder mixes.
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[*] posted on 11-10-2008 at 14:38


ya... but i think that can be a nice mixture to make flairs because the light is very bright. But not a good idea for explosive.
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