30 replies to this topic

[Mumbles]

Something I find very interesting is the picture of CuCl flame they have hanging in the hallways of the chemistry building here. Theres one of salts, and one of metals, so they always get the wheels turning when I see them. The CuCl is unmistakably green. I would imagine they are done in alcohol, and that probably gives a high enough temp to get into the green spectra. I can make perfectly beautiful blues with CuO based comps(chlorine donors of course included).

I've seen some comps containing lead. It's one of those things like Paris Green, Calomel, and the like that has gone to the wayside. Is it just me, or is it only things that help out blue that get banned or hard to find? No one uses it anymore due to the toxicity.

[hashashan]

maybe the green spectrum from CuBr is at high temperatures.. because low temps like KBrO3 + S + CuBr(yes i know its not safe, thats why i dont use it. make the most beautiful blue.

And toxicity well PbCl2 is not very toxic .. i mean it is but its fairly easy to handle due to its extremely low solubility

[Mumbles]

The problem with lead chloride, while it may not be soluble in water, it's soluble in human tissue and the stomach. Stomach acid solubilizes it fairly easily. It is also reportedly absorbable through the skin and fairly toxic through the lungs. It's not the lead chloride alone I'd be worried about, but rather the smoke.

[hashashan]

There are far more toxic stuff you guys use. There is the Pb3O4, Antimony stuff and many more things I wouldnt like to get into my system. If the smoke is a problem so dont use it in closed places.. trust me you wont poison yourself from some smoke from the air

[MDH]

If you know what smoke essentially is, you will find it easy to know that it can be just as deadly.

[hashashan]

Try to read between the lines
I know what smoke is .. and of course it is toxic. However when you are using a pyrotechnic device outdoors you get very minimal smoke in your lungs.
PS. one of the by products of BP smoke is KCN .. I didnt hear anyone dying lately from BP smoke.
Just dont light these stuff indoors or near you and i believe you will be just fine.
The smoke from crackling microstars is also contains lead and people use it all the time

[DeAdFX]

To answer your question to some extent...

I think your going to have a difficult time finding some decent organo bromides that will work for pyrotechnic application. Brominating tablets used in pools are most likely going to have shitty shelf life. You could try finding some polyvinyl bromide or making it by brominating ethene. Either way chlorine is by far cheaper and easier to do.

[Mumbles]

There is a very big difference between KCN from BP, which exists somewhere on the order of less than 1/10 of 1% of all the combustion products and a colorant/color promoter present in quantities between 5 and 20%.

I think testing bromine as a color promoter would be much easier to do in the liquid state. It's not simple, but Bromoethane or bromobenzene are possible to prepare on the laboratory scale.

[MDH]

Bromides still decompose into bromine gas when they are burned, don't they? You don't want to, you know, take a year off the life of your audience, no?

[Mumbles]

If one can control chlorine in a flame, you can control bromine. Chlorine is actually more poisonous than bromine. Bromine has the danger of being able to be spilled on skin in the liquid state, AND be inhaled as fumes at the same time. Chances are if any sort of free bromine compound is formed, it'd be HBr, which again isn't very good for you. In flame temps, it's too reactive to stay to much degree as free bromine.

[YT2095]

agreed, I`de sooner have Br2 around than Cl2 or F2!

I`v used Br2 here quite a bit in it`s elemental form as well as Cl2, Bromines nice in a way because if you keep it cool (a glass of cold water will do) it`s quite "tame", Cl2`s Always a gas at these temps, and you can`t see it very easily either, (not that you need elemental Chlorine for chlorinations).
Br2`s a little lest reactive, so the elemental form is quite handy (same with I2).

I`m wondering if perhaps some Longer chain alkane can be used for bromination? the VP should be good and with a long carbon string that gives you more Hydrogens to replace so you wouldn`t even need too much of it either.

as long as the Br was kept to the Reductor side (+) of a pyro comp and not the Oxidiser side (-), it should be quite stable too!

just a few thoughts

[hashashan]

Guys I really dont understand the panic of 50 grams of Br compounds 50 meters above your head.

[Mumbles]

Ideally it'd all be formed into CuBr anyway, which would float away, and be no more poisonous than any other blue star you've seen. I believe they were worried about elemental bromine being released. You'd probably get a bigger dose of poisonous halides from doing the laundry, drinking city water, or going swimming than from fireworks of this nature.

[hashashan]

YT2095 : Whats VP?

[YT2095]

Vapor Pressure, Sorry