Flying dutchman Posted May 26, 2008 Share Posted May 26, 2008 Hi, Today, whilst getting boared in class I decided to do some theoretical pyrotechnics to calculate the stochiometric quantities of chemicals to get good BP, Oskar told me to use the always used 75:15:10, but it seems to me that this could work better: 74.8%......KNO311.9%........S13.3%........CCould anyone maybe try this out , since I don't have any KNO3, and Oskar's scales are just crap... Thanks Link to comment Share on other sites More sharing options...
oskarchem Posted May 26, 2008 Share Posted May 26, 2008 Mods> Maybe moving this to a more analitycal forum, like the chemistry one? He didn't exactly know that this was for already TESTED compositions...? Anyway, he showed me these results and I somhow think that this BP would not be the best, as I find a high C content, and less Sulfur, (But the again, sulfurless BP dose exist)... So if anyone would have the sientifical spirit to try this one out, we would be greatful, as my scales are real bad... Link to comment Share on other sites More sharing options...
TheSidewinder Posted May 26, 2008 Share Posted May 26, 2008 Yes. Topic moved to Pyrotechnics Chemistry. I'm also fairly certain that this has been discussed before, but will leave it so that new members can have an easy reference, as well as allowing anyone to clarify anything posted. I also don't have the TIME today to search the forum for existing posts about it. Link to comment Share on other sites More sharing options...
Mumbles Posted May 26, 2008 Share Posted May 26, 2008 Burning black powder has over 30 products. A direct stoichiometry to K2S, CO2, K2CO3 and N2 will not be perfect. Those are the 4 major products, but like I said there are over 30. Chemistry of Powder and Explosives by Davis has a nice break down. Any increase in preformance over the standard 75:15:10 will be barely noticeable. However, I am never one to get in the way of experimentation. That ratio is pretty close to the PGI empirically derived "best" lift formula. 74 KNO3, 14 C, 12 S. Link to comment Share on other sites More sharing options...
asilentbob Posted May 27, 2008 Share Posted May 27, 2008 One thing you need to understand is that potassium nitrate from 2 different sources is inherently different. Perhaps one has slightly more impurities than the only. The same goes with sulfur. Which usually has clays or even carbonates in it. Same also goes for charcoal. We all know how big of a difference differnt charcoals make. The thing is that BP formulas have been different for geographical areas in the past because of the resources available to the people in the area. Perhaps they found that a certain formula tended to be more forgiving for their uses than the BP formulas for other areas. Now add in that different areas integrated the chemicals differently. Some using stone mills, some using slaves grinding away with essentially mortars and pestles... 75:15:10 is just ok. 74:15:11 ... perhaps this is slightly better for one species of wood when harvested after the first freeze of winter and cooked at a certain temperature for a certain length of time in a certain size container and when cut up into sticks of a certain size... Perhaps 76:15:9 is better when its more humid?Perhaps 77:15:8 is better 10,000ft above sea level where the air pressure is different?Perhaps 74:16:10 is better when the air contains a few ppm more CO2 than the global average?Perhaps 74:12:14 is better after being thermally cycled for 2 years in a certain old wood shed in a certain area of the country than any other powder normally would be in that area after that length of time? Do you see what I'm getting at?Theres just too many variables to tie down a perfect ratio because every situation, composition, and intended use is different. Pyrotechnics is not an exact science. Link to comment Share on other sites More sharing options...
WarezWally Posted May 27, 2008 Share Posted May 27, 2008 75:15:10 is good enough for me Link to comment Share on other sites More sharing options...
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