spitfire Posted July 10, 2012 Posted July 10, 2012 I have been testing with different colored stars and tried to improve them by increasing the flame envelope. As most of you might know this is done in some blue formula. It often asks for Hexamine. I tried to obtain red and green stars with a limited size, but with larger flames to increase the visibility. Or in other words, the ''size'' and light output of the stars. Of course some of you will suggest using Mg but i am looking for another way. The question: anyone tried this before and what where your results? Is it something that is worth to experiment and possibly useful for production?
Potassiumchlorate Posted July 10, 2012 Posted July 10, 2012 (edited) I suggest potassium chlorate blues without hexamine instead of AP or KP blues. But, sure, hexamine increases the flame, both with KP and AP. Edited July 10, 2012 by Potassiumchlorate
Mumbles Posted July 10, 2012 Posted July 10, 2012 The other common envelope enhancer is stearic acid/stearin. This is compatible with chlorates. It also is supposed to make pumping stars a dream. The common thread I associate all of these flame enhancers with is the ability to sublime/vaporize relatively easily. I'd bet something like sulfur, or maybe chlorine donors such as chlorowax and hexachloroethane or hexachlorobenzene might also work. Another trick I've seen is to use potassium benzoate in place of the metal. This speeds up the burn and heats up the flame like a metal, but without as much extra light output. I don't know if it'd increase the physical flame size. Using benzoic acid might increase the envelope size. It sublimes fairly easily actually.
spitfire Posted July 11, 2012 Author Posted July 11, 2012 (edited) I will only use KClO4 as an oxidizer in these tests. @mumbles, replacing the metal for K-benzoate.. would this make the composition slightly safer because of the absence of a metal, but on the other hand... you are basically making some sort of dirty whistle in some cases. Somehow i don't feel very comfortable when handling whistle compositions, i'd rather deal with plain color compositions or BP. Is just me, or is it something we should keep in mind when mixing/handling these modified compositions? EDIT: what makes a whistle composition so sensitive? and what ratio perc - benzoate makes the turning point for slow burning or the aggressive burning from whistle? What are the mechanics behind it? Edited July 11, 2012 by spitfire
Potassiumchlorate Posted July 11, 2012 Posted July 11, 2012 Chlorowax seems to have similar properties to stearin, in this respect, yes. I found out when experimenting with slight modifications of Hardt Blue #3. That comp contains both, but you can simply leave the stearin out and instead increase the amount of potassium chlorate with 2% (faster burning) or increase the resin fuel with 2% (slower burning but a bit deeper colour).
spitfire Posted July 11, 2012 Author Posted July 11, 2012 @ Potassiumchlorate, thanks, nice tip. i think i will go for increasing the resin fuel, as i am looking for smaller sized stars. Larger rolled stars are (to my opinion) easier to get right then small sized stars, like pea size. I admire the Chinese, who seem to be able to make the smallest stars still look pretty good. They use coreless rolled stars, but i didn't figure out what they use as a starting material. I have slit a lot of them in half, and most times they did NOT use tiny cut stars as a core.
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