8 replies to this topic

[Gary_1323]

Hello everyone,


First of all I'd like to introduce myself as a new (public) member. In fact, I am considering paying the membership fee to become a full UKPS member, with all the benefits that it entails. I have been deeply interested in pyrotechnics and chemistry (including the chemistry aspect of pyro) since childhood. As the Old English saying goes: "He who hath smelt the smoke is ne'er again free" (or something along those lines).


Now for my question:


I have read in some pyrotechnic literature that potassium or sodium sorbate can be used as an alternative to potassium or sodium benzoate/salicylate in whistle mixes, with perchlorate as the usual oxidizer. Has anyone here done any experimentation with a sorbate-based composition as an alternative to benzoate/salicylate in 'Benzolift', benzoate/salicylate-based burst comps for small shells and benzoate/salicylate-based whistle mixes?
How does a sorbate-based comp compare with one based on benzoate or salicylate?


Lastly, I know that there are some blue star formulas based on copper sorbate, but can a copper sorbate-based comp be made to deflagrate with enough ferocity to enable it to be used as blue-coloured whistle?

[dr thrust]

hi gary, yep i can confirm you can make whistle rockets using pot sorbate, here's a link with videos. including a copper sorbate whistle rocket test , but im afraid the copper kills off the whistle but could make good a blue propellant with a little parlon
funny thing is you must of read my mind as i was only thinking about how to make other metal sorbates , maybe zinc sorbate, and calcium sorbate , but how would one go about strontium/ barium sorbate when the sulfates are so insoluble in water?

Edited by dr thrust, 30 October 2011 - 10:20 PM.

[Gary_1323]

hi gary, yep i can confirm you can make whistle rockets using pot sorbate, here's a link with videos. including a copper sorbate whistle rocket test , but im afraid the copper kills off the whistle but could make good a blue propellant with a little parlon
funny thing is you must of read my mind as i was only thinking about how to make other metal sorbates , maybe zinc sorbate, and calcium sorbate , but how would one go about strontium/ barium sorbate when the sulfates are so insoluble in water?

Great-sounding whistle! Perhaps potassium sorbate whistle comps could be tweaked a bit so that they would become suitable for use as inserts in cakes and mines.

You could probably make Sr or Ba sorbates using one of the following methods (I might give the Sr and Ba salts a try myself):
Take a water-soluble sorbate (i.e. the sodium or potassium salt). Dissolve in distilled or deionised water to make a concentrated solution. Add concentrated hydrochloric acid to precipitate out the free sorbic acid. Filter and wash the crystals/ppt. with plenty of cold water. There you have your sorbic acid, which is approximately as acidic as acetic acid (they both have similar PKa values). Dissolve enough of the sorbic acid in hot water (it is only slightly soluble in cold) to make a concentrated sorbic acid solution. Keep the solution hot (~80 degrees Celsius) by means of a temperature-controlled hotplate. Now, very cautiously add the Ba or Sr carbonate in very small increments, taking care not to produce a mist (aerosol), as the carbonate and sorbic acid react with much fizzing (effervescence) to produce carbon dioxide gas (Ba compounds are very unhealthy for us, so it would not be a good idea to inhale the aerosol!). Stir vigorously at regular intervals to ensure adequate mixing of the reactants, or use a magnetic hotplate and stirrer bar. When no more of the carbonate dissolves in the sorbic acid and no more fizzing is evident, the sorbic acid has been fully neutralised to form the metal sorbate salt. I am unsure of the solubilities of Ba and Sr sorbates, but if they are insoluble even in hot water, then this method will produce a precipitate. If they have appreciable solubility, even in cold water, the solutions can be concentrated by slow evaporation under a gentle heat, then be allowed to crystallise.

Another method (probably more feasible):
Take a water soluble Ba or Sr salt (i.e. the nitrate or chloride). Make a concentrated solution. Do the same for your potassium or sodium sorbate. Heat both solutions on a hotplate to about 80 degrees Celcius (hot but not boiling). Add the hot Ba or Sr solution to the hot solution of the K or Na sorbate. Depending on the solubilities of the Ba or Sr sorbates, a precipitate might be formed immediately (like what happened in your copper sorbate video), or you might have to wait until the solution is cooled right down to room temp or below (put it in the fridge) before a precipitate forms. Filter the precipitate of Ba or Sr sorbate, wash it to remove all traces of unwanted cations (Na+ is notorious for interfering with colour comps), then allow to dry in a warm place. There you have your sorbates.


As for zinc sorbate, I can not see how it would be of any use in pyro, but the Ca salt might find use in orangy-red colour comps or glitters.

[dr thrust]

great stuff , just what i was looking for, ho! welcome to the forum
re:the zinc sorbate, just thought the comp may of emitted a bit of light and to see how if a anything, the zinc effects the whistle

[MDH]

Sorbates make excellent color fuels if you react it to other salts.

I've used it as a booster, and yes, as a "benzolift alternative" in 60 Sorbate Booster 40 BP ratios, I've used it in twine-wound salutes, I've used it in tiny quantities as a fountain accelerant. But I haven't used it as a whistle, and I would hesitate to call Chris' result as "Whistle". It's almost more like an angry high-frequency sputter. Definitely an interesting effect, and I'm curious about whether or not I could make spinning shell inserts out of it and whether or not 1% titanium would kill the effect.

Unfortunately I'm out of perchlorate right now and any I have is designated to color compositions so you'll have to experiment from here.

[starseeker]

Hello everyone,


First of all I'd like to introduce myself as a new (public) member. In fact, I am considering paying the membership fee to become a full UKPS member, with all the benefits that it entails. I have been deeply interested in pyrotechnics and chemistry (including the chemistry aspect of pyro) since childhood. As the Old English saying goes: "He who hath smelt the smoke is ne'er again free" (or something along those lines).


Now for my question:


I have read in some pyrotechnic literature that potassium or sodium sorbate can be used as an alternative to potassium or sodium benzoate/salicylate in whistle mixes, with perchlorate as the usual oxidizer. Has anyone here done any experimentation with a sorbate-based composition as an alternative to benzoate/salicylate in 'Benzolift', benzoate/salicylate-based burst comps for small shells and benzoate/salicylate-based whistle mixes?
How does a sorbate-based comp compare with one based on benzoate or salicylate?


Lastly, I know that there are some blue star formulas based on copper sorbate, but can a copper sorbate-based comp be made to deflagrate with enough ferocity to enable it to be used as blue-coloured whistle?

Wellcome to the forum,great first and second posts,i think you are going to enjoy the hobby

[dr thrust]

and I would hesitate to call Chris' result as "Whistle". It's almost more like an angry high-frequency sputter.

now dont forget chaps whistle is very sensitive stuff, especially when you call it names

Edited by dr thrust, 31 October 2011 - 09:57 PM.

[Gary_1323]

now dont forget chaps whistle is very sensitive stuff, especially when you call it names

I'd feel far safer working with a *relatively safe* whistle comp than very dangerous and unpredictable 'death mixes', like Armstrong's Mixture, a chlorate-sulphur/sulphide/ammonium salt comp or permanganate-based flash!

Of course, whistle mix (or ANY comp for that matter) have their inherent hazards; but some are more shock or friction-sensitive than others. Whistle mix is certainly more sensitive than K nitrate-based black powder.

Edited by Gary_1323, 31 October 2011 - 10:55 PM.

[Gary_1323]

Wellcome to the forum,great first and second posts,i think you are going to enjoy the hobby

Thanks! Oh, I've been enjoying pyrotechnics for quite some time!