Zammied Posted March 26, 2015 Posted March 26, 2015 Hi, have been trying to move into BP rocketry and I have KNO3 suffer and mixed airfloat charcoal, all thouroghly ball milled to almost talcum powder mesh size. When I ball mill them together for about 8 hours at 60% kno3 20% charcoal 10% S (what I have read is a good mix for lift powder) it burns at a decent rate but not like instantly which is what I've seen. Do I need to mill it longer or perhaps different charcoal?? My chemicals should be pretty close to technical grade pure. Any responses greatly appreciated!!
Mumbles Posted March 26, 2015 Posted March 26, 2015 What sort of rockets are you trying to make? If you intend to make end burners or nozzleless rockets, then you generally want as fast of BP as possible. Typically 75:15:10 KNO3:C:S is used for these. If you're looking to make nozzled core burners, then a slightly tamer fuel is generally used. I usually see proportions between 6:3:1 and 7:2:1 typically. You'll need to try to dial in based on chemicals, size of rockets, and how you're making them (ie. pressing vs. ramming, etc). If you're looking to make the hottest black powder possible, then you'll probably need to find a different charcoal source. Commercial airfloat is cheap and easily available, but not overly high performing. There are sources to purchase specialized charcoal for this purpose, but many just make their own by cooking a variety of woods available to them. Willow, eastern red cedar, some pines, paulownia, alder, balsa, are just a few examples of the known very fast charcoals. Eastern red cedar (ERC) has the advantage of being sold as a pet bedding in many places in the US. If you're from outside the US, there are going to be plenty of options as well, but they're just as widely talked about due to the proportionally fewer international members we have. Here is a somewhat more comprehensive listing of wood varieties: http://wichitabuggywhip.com/fireworks/charcoal_tests.html 1
captainG Posted March 26, 2015 Posted March 26, 2015 With a harbor freight mill and 5# of lead what would be a good weight of bp to make? Also is there a tutorial on here of how to modify the speed of the bm as if heard its too fast or is it ok as is?
Zammied Posted March 26, 2015 Author Posted March 26, 2015 Thanks for the reply!! I am from the U.S. and I am making nozzeled core burners which was why I was going with the more game mixture. I attached a video of the burn rate. This is not granulated after 12 hours of ball milling. Also yes I'm afraid it's my charcoal :/ I hate making and grinding it up and there are no willow trees where I live so I suppose I'll have to order some. Let me know what you think and if maybe after granulation it could be useable...
coogan1997 Posted March 26, 2015 Posted March 26, 2015 captain, a fellow member pointed me toward this article http://www.skylighter.com/fireworks/how-to/ball-mill.aspand I will do the same
TYRONEEZEKIEL Posted March 26, 2015 Posted March 26, 2015 Zammied. Powder straight from the mill is not useful in that state. It must be finished into lift etc. to burn quickly.
Mumbles Posted March 26, 2015 Posted March 26, 2015 For nozzled core burners you can definitely use commercial airfloat. Most people I know making this type of rocket tend to stick with it actually. They save the good stuff for when it's actually required.
Zammied Posted March 26, 2015 Author Posted March 26, 2015 Ah, if I attach a video, can somone take a look at the burn rate?
Andres1511 Posted March 27, 2015 Posted March 27, 2015 The burn rate is open air doesn't say much...Especially for rocket fuel I would ram it into a tube and test it like that.
BurritoBandito Posted March 28, 2015 Posted March 28, 2015 Zammied, if your rockets aren't performing well, it's possible that the problem isn't your BP. Perhaps if you gave a little more info about your tooling and construction methods it may help others to pin point the issue. If you truly believe the BP to be substandard then you should go to your local pet store, and pick up a bag of the eastern red cedar pet bedding as suggested by Mumbles. It makes great charcoal, and can be thrown straight into the mill, without being ground up first..
Zammied Posted April 10, 2015 Author Posted April 10, 2015 Alright, so i have improved my BP a bit. Part of the problem was my mill did not have enough media. It is now half full with lead media and I have switched to willow charcoal which i have bought and ground myself. So, now im having the problem of my small 3lb ball mill not being able to turn a heavy load well. ( I only make 100g powder at a time) If anyone knows where I can buy a mill that can turn 8ish lbs well, let me know! Im going to look tomarrow.
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