131 replies to this topic

[pyrotrev]

Because we are trying to edge up to the quality of paris green, or create a new formula which could prove useful and accessible while rivaling quality blues. Exotic does not always mean expensive or in inaccessible, just simply unusual within the currently accepted way of producing colours.

I quite agree. There's a lot of chemicals with derivatives potentially useful in pyrotechnics that we would consider "exotic" but are used in huge amounts in industry, and are really qute inexpensive.

Edited by pyrotrev, 01 August 2009 - 12:51 PM.

[Potassium chlorate]

William H. Browne, an Englishman, in his The Art of Pyrotechny, from the late 19th Century, mentions a composition with strontium chlorate. I know that the salt is hygroscopic, but since it obviously was in use more than 100 years ago, it shouldn't be impossible to make a composition of it today, should it?

If you substitute dried strontium chlorate for barium chlorate in the Weingart formula with shellac, wouldn't it be possible to get a really nice deep and red Bengal just as easy as the green one?

[pyrotrev]

I'm not sure how hygroscopic Strontium Chlorate is - anyone know?. The barium salt is OK even though it does contain water of crystallization. Having lots of chlorine about isn't quite so important in red flames as it is with green flames and neither do the emissions from potassium compounds disturb the colour quite so much, so it might be that there's not so much benefit in using Sr(ClO3)2 as there is with Ba(ClO3)2 - it would be fun to try though!

Edited by pyrotrev, 16 August 2009 - 03:59 PM.

[Arthur Brown]

Some of the hygroscopic salts may form better mixes when used in stars bound with a resin. I suspect that several resins can be used at around the 10% mark as both fuel and waterproof binder.

[Potassium chlorate]

Speaking of red: I discovered many years ago that you get a nice red from potassium perchlorate and salicylic acid, but how stable is it and can it be used for stars etc and what may the proper composition be? Salicylic acid has a rather complex formula at least to me, who only have high school chemistry education.

KClO₄+C₆H₄(OH)COOH---> KCl+?

[Mumbles]

I'd treat it with care. I'd expect it to be of similar sensitivity and stability to whistle mix. The acidic vs. basic nature of the more traditional salts may cause some added sensitivity. If you want a fast burning mix, I'd try something like:

75 - Perc
25 - Salicylic acid

That is just a crude calculation based on 7:3 whistle mix, and taking into account the higher fuel concentration. Extra fuels probably would do it some good to get the burn rate reasonable. I don't know what would maintain the color besides additional acid.

[Potassium chlorate]

I just discovered that if you simply put a small pile of it on the ground and light it, it will not become red at all but orange. You have to put it in a rather tight tube to get the red colour.

[MDH]

Hello everyone, due to a buzz of recent activity I've been unable to work on the chemical experiments. However today I was free, and decided to provide you all with the results of some tests I performed by reacting a mixture of fatty acids from standard typical hand soap with copper sulfate, to yield respective copper salts. I mentioned these before but had not experimented extensively with them.

Most soaps are composed of a variety of long-chain fatty acids.

Potassium Perchlorate / Copper "soap"

7:1 might make a good report composition but is otherwise just a very bright, fast flame.

5:1 burns powerfully, much like a star.

3:1 burns with a phase in between strobing and burning consistently.

2.5:1 burns with a strobe like behavior, and this smoulder phase could likely changed positively with the addition of other fuels.

2:1 burns with a long smoldering phase with short bursts of flame, and does not produce very much light.

The color saturation of all of these, however, is weak. The question yet still is whether adding a strong chlorine donor such as cpvc, saran or HCB will alter the burn rate positively or negatively.

Edited by MDH, 17 September 2009 - 05:04 AM.

[digger]

Interesting stuff.

I guess though the majority of the fatty acids are either Laric (C12) or Palmitic (C16) depending on the source of the soap.

So I suppose the metal content will be low in comparison to the C/H content. How did you get over the sodium contamination from the soap? As most soaps I would guess are produced using Lye for the sodium salts of the fatty acids.

By the way we produce 500 tonnes per week of fatty acids as a by product of our processing. We classify these into a few rough fractions Lauric (predominantly C12), Palmitic (Predominantly C16), and mixed (Mainly C18, C18:1 with a bit of C14, C20 (various saturations), C22). So to the point if you want some samples to play with send me a PM and I will post some out to you.

D

[MDH]

Interesting stuff.

I guess though the majority of the fatty acids are either Laric (C12) or Palmitic (C16) depending on the source of the soap.

So I suppose the metal content will be low in comparison to the C/H content. How did you get over the sodium contamination from the soap? As most soaps I would guess are produced using Lye for the sodium salts of the fatty acids.

By the way we produce 500 tonnes per week of fatty acids as a by product of our processing. We classify these into a few rough fractions Lauric (predominantly C12), Palmitic (Predominantly C16), and mixed (Mainly C18, C18:1 with a bit of C14, C20 (various saturations), C22). So to the point if you want some samples to play with send me a PM and I will post some out to you.

D

Hi digger. While the metallic content is low in long chain fatty acids, a blue is still visible in the flame. I would hazard a guess that with strontium and barium the colors would be much more prominent in the flame, though I am currently waiting to place an order to obtain barium and strontium bases.

The soaps can be tested of sodium contamination by simple burning tests - potassium based soaps will produce a white or purple flame.

Currently I don't need any source of fatty acids - but thanks for the offer! What I'm looking for right now are salt of calcium butyrate and other short-chain carboxylates or fats. While butter is an option it isn't the most pleasant one... (This doesn't mean I'm considering testing fatty acid compositions "over" - but there will be some time until the products I need arrive, and sources are scarce for most of what I am looking for right now).

On another irrelevant but similar note, It is interesting, that in a somewhat bizarre manual called the "Preparatory Manual of Black Powder and Pyrotechnics", the author specifies a composition using sodium propionate as a fuel, and describes the burn rate of the composition as being rapid.

[digger]

Interesting.

I am holiday at the mo so I don't have my texts to hand. But I am sure I can offer a fatty acid source that has far more C4 in it than rancid butter. If you have the kit to do vacuum distillation it should be easy enough to separate at reasonable temperatures (I have a mathematical model for the vapour pressures pretty much all fats at various temperatures).

It certainly sounds like an interesting diversion as the metal content starts to get significant when you start getting down to C2/C4.

If you get a chance it would be interesting to see some video of your results when you get these metal salts sorted out.

D

[MDH]

Which particular salts are you interested in seeing in action, and in what kind of composition? (i.e., A comparison of potassium perchlorate, parlon and copper sorbate compared to potassium perchlorate, parlon and a more typical copper compound).

Also, I am quite interested in your source of short chain acids.

[MDH]

Which particular salts are you interested in seeing in action, and in what kind of composition? (i.e., A comparison of potassium perchlorate, parlon and copper sorbate compared to potassium perchlorate, parlon and a more typical copper compound).

Also, I am quite interested in your source of short chain acids.

Sorry to double post, but are you still here, digger?

I am quite interested in the short chain acids you have available. Which particular byproduct salts are they?

Edited by MDH, 26 September 2009 - 08:47 PM.

[Alexander]

On another irrelevant but similar note, It is interesting, that in a somewhat bizarre manual called the "Preparatory Manual of Black Powder and Pyrotechnics", the author specifies a composition using sodium propionate as a fuel, and describes the burn rate of the composition as being rapid.

Important safety tip,

Ledgard's books are the least trustworthy information around. Random sources mainly patents are unreliable to start with.
He modifies methods and doesn't test them. He doesn't understand what he writes about or seemingly even basic chemistry.

He provides a synthesis for ammonium chlorate and describes it as an oxidiser "heavily used in high performance propellents, alone or mixed with it's perchlorate with aluminium".

What he writes is dangerous fiction. His work will kill people.

On a lighter note, I understand butyric acid and it's salts smell of vomit. Let us know how that works out.

[MDH]

I had noticed. In one he describes the process of tumbling a mixture of potassium chlorate, charcoal and red phosphorous. Given that he does appear to gather his information from random sources without knowing about it, with discretion, one can tell which compositions he lists are legitimate and have probably been used by someone out there, and which information is being given to him on the spot and is not safe at all. But I would indeed be wary of casuals wandering across his information and taking it at face value.

I'm still waiting for digger to get back to me on the source of short chain acids, at the moment. Not planning to react rancid butter with copper bases .