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/sci/ - Science & Math

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4108622 No.4108622 [Reply] [Original]

Pyrotechnics time. I'm trying to create a fuel, ideally based on methylated spirits (95% ethanol, 5% methanol), that has a flame colour other than yellow. I've managed to make a decent shade of green via adding boric acid, which as I understand it gives triethylborate/trimethylborate, which works wonderfully.

Now, a lot of articles found via the googlebeast suggest things like potassium chloride for purple, calcium chloride for orange, and so on - this simply does not work. It's possible the flame colouration imparted by the potassium chloride is too similar to the normal pale blue to be noticeable, however the calcium definitively does nothing, unless you literally light a pile of the stuff with a few drops of meths on it, or take a jet lighter to the crystals.

Ideally I'm looking for red, purple and a strong blue, however blue is always a bitch in pyrotechnics so I don't hold out much hope for that.

Does anyone have any suggestions, that they know to work when dissolved in alcohol fuels? Just because something flame tests a certain colour doesn't mean it'll be applicable, sadly.

>> No.4108966

-tactical bump-

>> No.4108982

Can't help you, but bumping for good topic.

>> No.4108991

Try organic salts such as calcium acetate which may dissolve better in the methanol.
Check wikipedia for your salts soliability in methanol

>> No.4108996

I remember doing this once... I forget exactly what I used, but I think I managed green, pink, purple, and bright red flames if I remember properly.

I know one of them was cupric sulfate. I think that was the green one. The other ones I believe involved manganese or chromium, I don't remember any others.
Any transition metal compound should get you a nice color.

>> No.4109052

>>4108982
Thanks, 'tis appreciated.

>>4108991
Well, I've tried strontium acetate, as my strontium carbonate did a grand total of sod all, and that didn't work either. Wikipedia indicates calcium chloride to be more soluble than the acetate, and CaCl didn't do anything much, as mentioned.

Copper compounds give good greens fairly easily, but boric acid gives a fantastic green already, and is less toxic than copper compounds (there's some skin contact during use sometimes). This is also why I use mostly ethanol as opposed to pure methanol.

>>4108996
I lack access to any sort of chromium compounds, I believe manganese will result in green as well however? I tried to make iron chloride previously, via mixing iron powder with HCl, but didn't realise that heating the resulting solution while exposed to air would form what seemed to be iron hydroxide sludge. So that was a right waste of time... was hoping it might result in a strong blue.

>> No.4109228

>>4109052
Magnesium is a white to yellow white
Cupric chloride is blue to green
Zinc burns green, try adding it so HCl and see if its soluable in the spirits

Most pyrotechnics are based on burning powders. Not sure of why you're trying to use spirits, but adding fine powders directly into the flames might give you more favorable results.

>> No.4109403

>>4109228
Well, the short answer is fire performance art. Think poi and firestaves rather than fireworks.

Magnesium has a tendancy to raise temperatures to unsafe levels; that said I have tried epsom salts in meths, no visible change though. I'll try CuCl for a shot at blue, but due to toxicity it isn't ideal.

>> No.4109418

If you're looking for blue, don't use CuCl. That burns green with maybe a blue tint. CuSO4 burns blue.