dangerousamateur Posted April 4, 2012 Posted April 4, 2012 I read several variants now, mostly 70/30 and also 76/23. I would expect the more oxidizer rich fuel to be hotter, but how great is the difference? I did some experiments with some very small rockets powered by 70/30 and cu oxychloride like it is mentioned in several tutorials. This does not burn fast enough, I want more power and i wonder if 76/23 is worth to try.
FlaMtnBkr Posted April 4, 2012 Posted April 4, 2012 I'm surprised 70-29-1 (?) with cu oxychloride wasn't hot enough in a small rocket. You said very small so was it bottle rocket size? Did it have a core or end burner? How fine is your benzoate? It seems like coarser benzoate still has pretty good power, it just doesn't whistle good.
dangerousamateur Posted April 5, 2012 Author Posted April 5, 2012 so was it bottle rocket size6mm (inner d.) x 40mm tubes. About the size I dare to press in my vice without proper equipment. Normal spindle length would be 12mm, I used 16. Otherwise just normal whistle rocket specs. How fine is your benzoate?Pretty fine, free flowing. Like it came from the dealer. Don't have a ballmill. Potassium benzoate. Same with the perchlorate. There was still a slight smell of acetone in the fuel, but not much. Maybe this slowed it down. I'm surprised 70-29-1 (?) with cu oxychloride wasn't hot enough in a small rocket.They flew quite well, but i want bullet performance & more payload (tested 2-4g). As long as the tubes can keep the pressure - why not?
Wiley Posted April 9, 2012 Posted April 9, 2012 Maybe a bit off topic, but I had a question about benzoate whistle mixes as well. I've heard that potassium benzoate is less hygroscopic than other fuels commonly incoporated with potassium perchlorate to make whistle. Is this correct? I am mainly interested in using whistle as a booster in shells. Does a potassium benzoate whistle mix have less power for this application than one made with, say, sodium salicylate? Any input would be appreciated. Thanks!
Seymour Posted April 10, 2012 Posted April 10, 2012 Potassium benzoate is less hygroscopic than the Sodium benzoate and salicylate, yes. I have heard than Sodium salicylate is the more powerful of the three in rockets, though I've yet to use this fuel myself. This is likely to translate in to the same for booster, however it will not be by all that much, and in my opinion the lower water absorbing properties of Potassium benzoate outweigh this.
Potassiumchlorate Posted April 10, 2012 Posted April 10, 2012 I wish I had a press for rockets. I have potassium perchlorate, potassium benzoate and copper oxychloride.
Mumbles Posted April 10, 2012 Posted April 10, 2012 You can check out Danny's whistle data to get an idea. It seems from his data it would seem that the salicylate data isn't entirely consistent, or at least very sensitive to the catalyst used. I don't do many rockets, but it just strikes me as quite variable. http://www.wichitabuggywhip.com/fireworks/rockets/whistletests.html
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