102 replies to this topic

[vaslop2005]

I was thinking more along the lines of

30 K2CO3 (oxidiser)
30 Mg (fuel)
15 PVC (chlorine donor)
25 Colour agent (colour donor)
bound with NC to reduce the hygroscopicity

as a base mix. I have never tried this before, but would love to hear the results.

I am guessing that using a common oxidiser would make more repeatable results, but experimenting is the only way to find out. Remember (the rather dull speech about safety) even though you think its safe, it could react unexpectedly, so take care.

[MDH]

The carbonates work, but I find the sulfates to be far superior - and even cheaper in some cases.

I often make stars out of calcium sulfate, 1000 mesh granular aluminum and sulfur, bound with water - they produce a fierce burning bright light. When concentrated inside of containment as a fine granule product, they double as a report composition.

In fact all of the metal oxyanions work perfectly well with a metal fuel, even the borates as reported by another one of our members. Halogen oxidizers are not the only option.

[CCH Concepts]

I'm thinking this could be the way to go as most of the chemicals being discussed are pretty much readily available and used widely in many industries so they should be cheap and wont raise any eyebrows buying them.

if there was no need for nitrates, chlorate's and perchlorate's life would be a lot easier.

but there comes the problems of blues, can any of these alternatives burn with a low enough temp?

[pyrotechnist]

that is one problem, though if you think about it at least a large proportion of the cost is reduced by just needing perc for blue, magenta, pink, purple which is more or less all based off the same formula with different quantities of strontium carbonate and some copper compound. Can carbonates work with charcoal? mite sound stupid but just curios.

[vaslop2005]

the problem is, when you want to create a low temperature flame the oxidiser needs to melt/decompose at a low temperature, so that it can sustain the reaction when its flame is cooled, (and this is why ammonium perchlorate and potassium chlorate are the best)

But other colours yes, and even greens will become a lot safer, because of the insolubility of barium sulfate.

and sorry but carbon can not burn with carbonates, as the decomposition of carbonates forms CO2, and will not provide the oxygen that it needs to combust.

although, lithium carbonate and caesium carbonate both seem to decompose at a relatively low temperature. Lithium has the problem of emitting red (I will experiment this one though at some point), and caesium (although emmiting blue) is insanely expensive.

I fear that nitrates and perchlorates atleast will always be needed in pyro in the near future, unless these problems (including price) can be overcome.

V

[seymour]

This whole price thing is just not clicking for me.

Unless you need to go to crazy lengths importing them in small quantities from middle me, Potassium perchlorate, or indeed most other conventional oxidizers are pretty cheap.

Magnalium however, I might be wrong here, I've not checked my facts here, has always seemed much more expensive. Most carbonates are indeed very cheap, but for me, Strontium carbonate has always been a lot more than KP too.

I'm not saying that this makes all the experimentation a bad idea, in fact I quite like it... experimentation makes this place more vibrant.

As for copper metal being used as a fuel... I'm sure I'm not the only one who added powdered charcoal and CuO together in chemistry class and heated it until 'whoosh' it became Copper metal and Carbon monoxide. It's certainly not a reactive metal.

[pyrotechnist]

Carbonates seem cheaper here to me than perc. Maybe it is cheaper if bought in large quantities but I dont have the facilities to store such large quantities of chemicals. I am going to keep testing these out anyhow and see what I come up with, preferably I want stars that do not leave molten metal slag behind, bright, same brightness, good depth of colour, same duration etc so that they compliment each other.

[seymour]

Certainly most carbonates are cheaper than perc. Strontium and copper carbonate may cost about the same, but Potassium, Barium, Calcium should be a lot cheaper.

Specifically, it's the large quantity of metal powders that looks like it might undermine the cost saving to me.

However, if you make your own magnalium, it's not necessarily the case.

Perhaps to help reduce the slag you could add a small quantity of Potassium perchlorate, Strontium nitrate or Barium nitrate depending on the colour, or use Sulfates like MDH suggested.

I might be skipping the point here, since it seems that you are wanting to experiment for experimenting sake (which is great!) but if you can get your hands on Carbonates and cheap Nitric acid, the nitrates are available for a very low price.

I guess with Nitric acid being somewhat hard to find, I might be suggesting something that is very hard to do for some people.

Good luck!

[Arthur Brown]

Weingart lists lots of formulae with calcium sulphate, even some that burn under water. Calcium sulphate of course being Gypsum which is Plaster of Paris. Now that should be cheap as an ingredient, buy a bag of plaster! These formulae were made wet, so the plaster set hard. Recently I heard of someone making one of Weingart's formulae dry, and using NC lacquer as binder trying to avoid entrapping the water of hydration. (dry plaster is calcium sulphate hemi hydrate, set plaster is tetra hydrate) Whether this was successful wasn't reported.

[pyrotechnist]

Mite try the sulphates out, anyone know where one could obtain Strontium Sulphate though? anyhow I have now come up with a universal formula that creates excellent and bright colours with Red, Orange, Yellow, White, Pink, Magenta, Green all fully workable and beautifully vivid colours for such a cheap formula. Will upload my video to youtube showing the basic red, orange and yellow in a fountain. I also find that if you use 400 - 500 mesh MgAl the comp burns very much like a coloured flash powder and blindingly bright! I was left with a red dot in my eye for a few minutes. It uses a small amount of perc to make the burn rate smoother though they also work without it but depending on the fineness of your MgAl the burn rate can be a little varied and they are also harder to ignite.

[MDH]

If you have sodium or copper sulfate lying around, you can react strontium carbonate with acetic acid and react the strontium acetate with the copper sulfate. The result, of course, will be copper acetate and strontium sulfate - which are both useful in their own right. Copper acetate will make passably nice blues (superior blues if you have ammonium perchlorate lying around, though it can't be bound with water).

Edited by MDH, 26 June 2010 - 08:22 PM.

[CCH Concepts]

would manganese dioxide be another option, i don't know what its color spectrum is or any incompatibilities. but it seems cheap even on ebay

http://cgi.ebay.co.u...=item3efb080a02

[CCH Concepts]

there is also nickle, barium and zinc sulphate's now we all know barium burns green, but what about the rest?

[Mumbles]

Nickel is known to produce nickel tetracarbonyl as a combustion product, which is extremely poisonous. I would shy away from that one personally. Manganese, at least the metal, makes kind of a lime green type of color.

You know, I wasn't thinking about the metals when I made my aluminum reducing them comment. Why would you bother using MgAl instead of just Mg with those mixtures? You're wasting half the fuel, and producing a strong blackbody emitter in the process.

[pyrotechnist]

To expensive for me magnesium, though I do think metal sulphates produce a cleaner burn than the carbonates with MgAl. Would German Dark Aluminium work with any of these, especially sulphates?