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simple colored flame formula?


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#1 neo

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Posted 18 March 2006 - 10:18 PM

Hi all!

okay, in a few weeks I'm having a chemistry "show" (school project) about fireworks, so I thought that I would make some simple colored fire (10-20grams of finished comp). the idea is to mix the composition and then light it in front of my class. I have very little time on me, so I want something that do not contain many chemicals, or take long to mix. and it would be good if it didn't produced to much smoke, since I'm going to do it inside.
these have I looked into:

red:

Strontium nitrate.................................66
Potassium chlorate................................25
Powdered shellac..................................9

green:

Barium nitrate....................................7
Potassium chlorate................................3
Sulfur............................................2
(is it possible to change KClO3 to KClO4 in this comp to make it safe?)

blue:

Potassium chlorate................................7
Copper(II)sulfide.................................2
Sulfur............................................4
(same question as above, can I change KClO3 to KClO4?)

Which would you prefer to make? I want a really good color.
If you know any other formulas, then I would appreciate if you posted it!

And I have to know the formula on Tuesday, because my teacher needs some time to buy the chems..
Pyrotechnics, the art of fire!

#2 Karl

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Posted 19 March 2006 - 12:07 AM

I have used a Degn, Purple formula before. And it worked a treat. This formula is from Westech :

Potassium Perchlorate : 9
Stronitum Nitrate : 7
Copper (II) Oxide, Black : 7
Sulfur : 5
Polyinvyl Chloride (PVC) : 0.5

Have fun!

#3 Electron

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Posted 19 March 2006 - 03:02 AM

"green:

Barium nitrate....................................7
Potassium chlorate................................3
Sulfur............................................2
(is it possible to change KClO3 to KClO4 in this comp to make it safe?)"

Swapping KClO4 for KClO3 would work i think, but it will be safer, not safe. Since the green colour is coming from the barium nitrate why don't you leave in the chlorate and swap the fuel(sulphur) to make the mixture safer?

For the blue formula i would swap the chlorate for the perchlorate, you do not really want to be mixing those chemicals for the first time in front of your chemistry class.

Here are a couple of formulas i have tried:

Red:
Potassium chlorate .... 10
Strontium carbonate.. 3
Shellac .................... 2

Gives quite an intense red but quite smokey if i remember correctly.

Green:
Potassium nitrate .... 28
Sulphur .................. 5
Charcoal ................ 14
Zinc ....................... 80
Dextrin .................. 2

This is actually the formula for a 'granite star', it burns with a white and green colour. The colour produced is not great, but the fact that barely any oxidiser is used compared to total fuel interests me, and if you could explain why that is i'm sure your chemistry class will be impressed, i know i would be.

Good luck with your project!

#4 Creepin_pyro

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Posted 19 March 2006 - 03:27 PM

Just one thing I'm a little concerned about - burning 30-60g of composition inside will produce quite alot of smoke which you don't want the whole class to be breathing in...

Seeing as you're doing the tests in school, I'm assuming you will have access to a fume-hood. It would be a good idea to use it - and if you're going to be using Barium Nitrate, I'd suggest mixing it under the hood aswell. Last thing you want is for loads of Barium to be floating around the room...

Edited by Creepin_pyro, 19 March 2006 - 03:28 PM.


#5 neo

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Posted 19 March 2006 - 04:51 PM

I?m not going to make that much, max 20 grams.
and I thought about that with barium, and I doubt that those fumes are healthy.. so I think I'm skipping green.. so now I'm in to red flame.. or blue =)

in this formula:
Potassium chlorate................................7
Copper(II)sulfide.................................2
Sulfur............................................4

if I change the KClO3 to KClO4, do I have to change the amount of oxider?
Pyrotechnics, the art of fire!

#6 fishy1

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Posted 19 March 2006 - 10:05 PM

I?m not going to make that much, max 20 grams.
and I thought about that with barium, and I doubt that those fumes are healthy.. so I think I'm skipping green.. so now I'm in to red flame.. or blue =)

in this formula:
Potassium chlorate................................7
Copper(II)sulfide.................................2
Sulfur............................................4

if I change the KClO3 to KClO4, do I have to change the amount of oxider?



yes you do, can't remember by how much.

btw, the sulfur will give off SO2, which is not nice smelling.

#7 neo

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Posted 20 March 2006 - 05:40 PM

if my calculations are correct (which they probably aren?t) then I need 6,5 parts kclo4 instead of 7 parts kclo3..

anyway, one more question, how fast will these formulas burn? I want it to burn at least a few seconds, so they can see the color..

edit:
found this in a old skylighter newsletter..

Ammonium perchlorate 82
Copper benzoate 18

will this work?
because as I said before, I want a simple comp..

Edited by neo, 20 March 2006 - 05:54 PM.

Pyrotechnics, the art of fire!

#8 fishy1

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Posted 20 March 2006 - 09:53 PM

if my calculations are correct (which they probably aren?t) then I need 6,5 parts kclo4 instead of 7 parts kclo3..

anyway, one more question, how fast will these formulas burn? I want it to burn at least a few seconds, so they can see the color..

edit:
found this in a old skylighter newsletter..

Ammonium perchlorate 82
Copper benzoate 18

will this work?
because as I said before, I want a simple comp..



yes, that blue is meant to be a VERY good blue.

however, i'd have a comp in reserve as even a teacher might have trouble getting them.

#9 Creepin_pyro

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Posted 20 March 2006 - 10:58 PM

Neo - that composition will not give a very good blue when burnt as a loose fine powder, and will also burn extremely fast, as is the case with many AP-based blues when not consolidated into a star/lance. Adding a small percentage of wood meal may slow the burn speed down a bit without affecting the colour too much, and another vaguely plausible solution would be to increase the percentage of Copper Benzoate to just above 22% (reducing the AP accordingly), as this will slow the burn and improve colour saturation, but I would still advise against using it.

Further to the above, I don't think your teacher would be able to order Copper Benzoate easily, and might not be overly keen on ordering Ammonium Perchlorate, seeing as it is classed as an expl0sive!

For your blue, you might want to consider using a blue lance formula using Copper powder. Try the Skylighter newsletter archives and rec.pyro - I think there's also a green fire formula on Skylighter which uses Copper powder and Potassium Nitrate so you can avoid using Barium Nitrate, but I've never tried it so cannot vouch for its worth.

Edited by Creepin_pyro, 20 March 2006 - 11:09 PM.


#10 EnigmaticBiker

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Posted 21 March 2006 - 12:27 PM

Just one thing I'm a little concerned about - burning 30-60g of composition inside will produce quite alot of smoke which you don't want the whole class to be breathing in...

Seeing as you're doing the tests in school, I'm assuming you will have access to a fume-hood. It would be a good idea to use it - and if you're going to be using Barium Nitrate, I'd suggest mixing it under the hood aswell. Last thing you want is for loads of Barium to be floating around the room...

Another reason for using a fume hood, I'd imagine the school has smoke/fire detectors (and possibly sprinklers!).

For demonstration purposes a white background might help people see colours more clearly.

Another colour:-

Yellow fire composition #1
Source: rec.pyrotechnics. Composition from "Magic With Chemistry"[7], chapter "colored fires"
Comments:
Preparation:
Potassium nitrate.................................4
Sulfur............................................1
Charcoal..........................................2
Sodium chloride...................................3


I've not actually tried this but it should be a relatively safe mixture to mix. The burning speed can be controlled by adding more NaCl or reducing the sulphur.

Hope your demonstration goes well.




#11 pyrotrev

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Posted 21 March 2006 - 07:52 PM

Hi Neo

I've done some lectures for the Royal Chemistry Society, for red I used a KClO4/SrCO3/Red Gum mix (shellac would work almost as well), yellow was KClO4/NaCl/Red gum/, green was KClO4/Ba(NO3)2/red gum and blue was KClO4/lactose/CuO/parlon - on reflection though if you're using dry mixes almost immediately (as you have to with NaCl), it should be possible to use KClO4/fuel(i.e. shellac)/CuCl, probably easier to get from standard scientific suppliers than a chlorinated plastic/rubber powder. Chlorate/perchlorate and sulphur mixes are not good news.
I found that 10....20g of composition was plenty, I burnt them on 7cm x 7cm squares of 25mm thick wood in which I'd drilled out a shallow 25mm diameter hole just to give a bit more duration to the flame. All were done in a fume cupboard, the intensity of light is such that it's really not a problem. In fact I had the audience move to the back of the lab (it was a big room) to get the best effect, alternatively if the room is small you could put a shield in front so they only see the reflected light.
Remember you'll need to follow normal mixing procedure. If you use barium nitrate it's a mask, gloves etc. job, that stuff is POISONOUS.
Trying to do something very beautiful but very dangerous very safely....

#12 neo

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Posted 21 March 2006 - 09:47 PM

thanks a lot pyrotrev! =)

I'm going to talk to my teacher tomorrow and see what he says..

would you like to give me some hints on the ratios i should use?
something like this to the red?
KClO4.......10
SrCO3......3
Shellac.....2

and how should it be for the blue (KClO4,CuCl,shellac)?
and yes, I will dry mix it, and ignite it immediately..

I think I will skip green color, I don't want to use Ba(NO3)2 inside, and it's to complicated with all the health protection needed..

@Creepin_pyro
I looked at those formulas.. but they were I bit to advanced (many chems..) I want 3-4 chems max.. thanks anyway.. I maybe give them a try myself.

thanks for all your post one more time!

Edited by neo, 21 March 2006 - 09:50 PM.

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#13 pyrotrev

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Posted 23 March 2006 - 12:04 AM

thanks a lot pyrotrev! =)

I'm going to talk to my teacher tomorrow and see what he says..

would you like to give me some hints on the ratios i should use?


For Red I used:

KClO4 65
SrCO3 20
Red gum 15

Yellow

KClO4 75
Red gum 15
NaCl 10

For blue I used

KClO4 60
CuO 10
Saran resin 10 (or other chlorinated hyrdocarbon)
Lactose 20

If you can't get Saran, Parlon or PVC powder and are using CuCl I would guess the mix as:

KClO4 64
CuCl 14
Lactose 22

I suspect this is a little short of chlorine (it seems to be best to have an excess) and hence won't give an ultra deep blue, but should give the right sort of idea - I'd be interested to know how well it works. BTW, the reason for using a sugar as the fuel (normal sucrose = icing sugar will work as well) is to keep the flame temperature down, to stop the CuCl molecule dissociating and hence improve the depth of colour.
All ingredients should be finely ground individually to start with. roughly mixed by hand, then passed through a sieve (20...30 mesh) a couple of times to enure good mixing.
Trying to do something very beautiful but very dangerous very safely....

#14 neo

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Posted 24 March 2006 - 07:55 PM

thanks a lot pyrotrev!

have learned a lot from this thread.

just one last question, how will these formulas work as stars?
if they don't, what is the deferens between these and stars formulas?
Pyrotechnics, the art of fire!

#15 pyrotrev

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Posted 25 March 2006 - 09:58 AM

just one last question, how will these formulas work as stars?
if they don't, what is the deferens between these and stars formulas?


I don't think they'd be the best. For a start, using stuff like NaCl would give you severe consolidation, drying and storage problems, since it's hygroscopic: the only reason I used it in the coloured fire mix was easy availability and the fact that you're mixing just a few hours before burning, it would need to be replaced by sodium oxalate or cryolite. Secondly, if you're consolidating using water to damp the mix, you would need to add a water soluble binder such as dextrin or glutinous rice starch. Also you might want something slightly fiercer burning for some stars, so you'd certainly need to stick with red gum (accaroid resin) raher than shellac as fuel, I forgot that shellac burns slower than red gum with KClO4 when writng my earlier post. Check out some of the formulas pinned at the top level of this forum. There's a lot more to make good usuable fireworks than simply something that burns with a pretty flame!. BTW Neo hope you got my PM.

Edited by pyrotrev, 26 March 2006 - 10:15 AM.

Trying to do something very beautiful but very dangerous very safely....




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