dwheadstone Posted July 26, 2013 Posted July 26, 2013 Yesterday I made some more using the same recipe I used last time but with three changes and it burned slower (30 seconds per foot and not as energetic ? I thought it would be faster using black (#1) willow charcoal last time it was(15 seconds per foot) airfloat mixed hardwood charcoal ? Last time I used the fine powder left over from granulating my HM BP ( Using STA-FLO HOT water)This time I used mill powder before (#2) granulating ( STA-FLO (#3)COLD water ) Was it because I did not use granulated powder ? Was it the cold water ?
FlaMtnBkr Posted July 26, 2013 Posted July 26, 2013 (edited) Wetting and granulating does seem to make hotter powder. I would think that would translate to faster BM. But hot water will dissolve more KNO3 which you worked hard to mill into a fine particle. Using cold water to granulate and then drying as fast as possible helps. A sunny and breezy day helps and should have it dry in a couple hours. If it takes closer to a day to dry it will probably be noticeably slower. You can also wet with alcohol which shouldn't dissolve any nitrate, but is more expensive. What binder are you using, because they can slow it down some too. Did you make the charcoal or did you buy it? I am surprised it was twice as slow with those changes and using willow charcoal. Edited July 26, 2013 by FlaMtnBkr
dwheadstone Posted July 26, 2013 Author Posted July 26, 2013 Dextrin is the binderAirfloat onlineBlack willow onlineBp made using skylighter recipe using ballmill
bob Posted July 29, 2013 Posted July 29, 2013 (edited) You can also wet with alcohol which shouldn't dissolve any nitrate, but is more expensive. I would think that this means it will not dissolve kno3.bob Edited July 29, 2013 by bob
FlaMtnBkr Posted July 29, 2013 Posted July 29, 2013 The only thing that will dissolve the KNO3 is any water in the alcohol. So the higher the percentage the better. New denatured should be close to 99% for most brands. But alcohol can absorb water and a lot of alcohol on the market is surplus that is mixed with other alcohols and can have more water than it should. But, it will dissolve a very small amount of KNO3 and will be better than water. But water makes plenty fast BP, usually hotter than Goex if using a ball mill and hot charcoal. And alcohol will actually carry away a certain amount of water as it evaporates though I forget the name it goes by. Maybe azetropic? Using a BP tester 4 g of Goex can get a 5 second flight time. I've made BP with hot charcoal and water with a 9 second flight time. Quite the difference, and you don't need BP that hot for most things. I think Ned Gorski has an article on Skylighter on how he makes his hottest BP using alcohol. I'm rambling but let us know if you have more questions.
Poindexter Posted August 13, 2013 Posted August 13, 2013 Azeotropic bonds are the ones that hold that last little bit of water in your otherwise almost pure alcohol beaker. http://en.wikipedia.org/wiki/Azeotrope This why the commercial corn ethanol producers screamed bloody murder to keep MBTE on the market. To mix ethanol into gasoline it must be absolute, 100%, 200° proof ethanol with no water in it. Otherwise it screws up the gasoline. Among gasoline, water and ethanol you can mix any two, but not all three, OP, I can't help you; but I am using higher and higher concentrations of isopropyl, less and less water, at my end.
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