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Gary

Member Since 03 Feb 2007
Offline Last Active Nov 25 2009 07:29 PM
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Topics I've Started

Amorphous Boron for pyrotechnic greens. Any formula?

25 November 2009 - 07:16 PM

I have a reference to a inorganic chemistry textbook which states that the amorphous form of elemental boron (appearance-wise, it is a dark brown to black powder) is used in pyrotechnics to produce greens.
Has anyone heard of any formula employing this chemical? Perhaps it might be worth experimenting with it to find out whether or not it is any good for green stars. The active species responsible for the green emission is the BO. radical. Elemental boron has applications in military pyrotechnics, but in recreational pyrotechnics (fireworks) it is unheard of.

Why is Mg/Al alloy (magnalium) essential in crackle formulas?

06 November 2009 - 12:45 PM

Magnalium (MgAl) alloy seems to be included in every crackle formula in combination with CuO, lead tetroxide or bismuth subcarbonate/oxide.
Is there any particular reason for this? I mean, why can't either of the parent aluminium or magnesium metals be used instead of the MgAl alloy? Could a 50/50 mixture of fine magnesium and aluminium be used, or is it essential for it to be in alloy form?

Copper oxalate for blues

27 October 2009 - 02:57 PM

Hi,

Has anyone had a go at making copper oxalate (copper carbonate+ aqueous oxalic acid or aqueous copper sulphate+ aqueous sodium oxalate) for blues?
I would imagine that the flame would be cooled by the carbon monoxide or carbon dioxide gases produced by the thermal decomposition of the copper oxalate.

Nano-sized aluminium

21 March 2009 - 01:56 PM

Hi,
I am trying to make some very, very fine aluminium powder in the nanometre particle size range.
Wary of the hazards involved, namely pyrophoricity (spontaneous combustion in air, possibly catalysed by moisture), I might try ball-milling aluminium foil (kitchen foil is readily available) under oil or kerosene, in order to exclude oxygen and moisture and thus prevent a flare-up. After several days of milling, I then intend to remove the oil by dissolving it in a lipophilic (oil-soluble) organic solvent, such as hexane or toluene. Residual solvent can be removed from the aluminium by evaporation at room temperature. (most organic solvents are volatile).
Question is, would the very fine aluminium produced by this method be safe to store without the risk of spontaneous combustion (pyrophoric flare-up?)

Barium and Strontium Perchlorates...any use in pyro?

14 November 2008 - 11:09 PM

Are the perchlorates of barium and strontium hardly ever used in pyrotechnics?
Do they have problems with hydroscopicity or stability?
By employing a perchlorate of barium ( for green) or strontium (for red), we have an oxidiser, chlorine donor and colour agent all originating from a single compound.
I could easily make these compounds...... :D