Rocketman14 Posted May 13, 2016 Posted May 13, 2016 This topic was from another thread. I wanted to hear if anyone else has ever used it for BP. Looked ok to me I thought, but didn't perform lifting a shell like I had hoped, however I only used 12grams to lift a 150 gram shell. I got im guessing 100-150 feet. I've gotten sone good advice about other wood to try, and I plan to. I'd love it if I was able to get red maple to burn really fast though, since this charcoal gets made in my woodstove almost by default. I am all about sourcing things that can save me time that I can spend building more rockets and shells! Here's a couple videos of me test burning a line of powder and a spollette. Thoughts? https://youtu.be/izOhmRRI66k https://youtu.be/C6Gmv35FhUI
PhoenixRising Posted May 13, 2016 Posted May 13, 2016 Not bad at all, but I think it's just a touch slow. There should be just a little more "poof" when it lights. Can you please take us through the process of how you make your BP? If you are milling it in a ball mill, how big is the mill? What kind of media are you using? (lead, brass) And also, how long is it being milled for? Things to watch for: If you are milling in a cheaper ball mill (like I am), make sure to open it every hour and scrape down the sides as it can tend to clump a bit. This is important to remember. Also, when you are granulating your powder make sure not to use too much water as it can cause the KNO3 to recrystallize coarser and slow things down. And lastly, how was the spolette constructed? As it looks from here it just needs to be a little bit shorter. Using faster BP will speed that up a touch. Also, the harder you compress the powder in the spolette the longer it will burn. The more detail you give about the process the better for everyone to help troubleshoot. You're pretty much there it seems, hopefully someone with more knowledge will chime in.
Rocketman14 Posted May 13, 2016 Author Posted May 13, 2016 It would be great to see some burn Tests of other members good bp. The test I came up with was just enough powder to fill level a .25"x.25" crevice I cut in a board. I'll get back with more stats about my process later this eve.
Rocketman14 Posted May 13, 2016 Author Posted May 13, 2016 Hi Phoenix, so I have been ball Milling my charcoal for around 3 hours, which is about how long it takes for me to be able to pinch into it and not be able to feel it between my fingers. I gather that it's mostly pretty much airfloat because disturbing it sends the black stuff flying. I add my kno3 and sulfur and mill the comp. I was milling 6 hours after that, but didn't see any difference between 3 and 6. Media is what was free, which in this case means marbles. To granulate Ive been using a 6" kitchen screen (scoop). The openings are a little larger than that of a standard window screen. As far as the water content goes, I have already once made the mistake of adding too much and it seemed like it took forever to dry it out to something workable.. needless to say I don't get impatient with it anymore when adding my h2o/denatured alcohol mix to my green meal. That about it I guess. Oh yeah, my ball mill, such as it is, my own creation of a half inch drill, turning wooden dowels with pieces of rubber fuel hose to grip the jar. My jar is 4" sdr35 pvc with solid end caps. I set it to turn around 60-70rpm, nothing fancy..I've got about 30 minutes into and some stuff I had lying around. I'll post a pic if I can figure out how.
Rocketman14 Posted May 13, 2016 Author Posted May 13, 2016 Oh right, spollette length. Yes it is long, I did so on purpose, I figured I could more accurately Calc the burn rate with a longer duration. It was never intended for use in a shell. The one in that shell was half the length of this one.
Nessalco Posted May 13, 2016 Posted May 13, 2016 Media is what was free, which in this case means marbles. You really should read through this thread. http://www.amateurpyro.com/forums/topic/9798-ball-mill-explosion/ Kevin
Rocketman14 Posted May 13, 2016 Author Posted May 13, 2016 Thanks, I no more than finished reading it and I saw you added that reply. I didn't realize glass marbles could create a spark.
BlueComet24 Posted May 14, 2016 Posted May 14, 2016 I think we've all over-wetted BP or at least some comp at least once. The trick is to be patient and consistent (experience helps, too). Adding 20% the mass of the BP in water seems to be just about perfect, but try starting at 15-18% and working your way up from there. The amount required can change based on how porous your charcoal is. Using a mixture of alcohol and water can help to wet the charcoal, but don't go above 25% alcohol, or the dextrin/SGRS might not work so well.Milling together sulfur and KNO3 isn't going to do much besides grind them to a fine powder. Milling the KNO3 into the charcoal is mostly what makes the BP faster, as it crushes the KNO3 into the charcoal's pores. If your KNO3 isn't a fine powder (I assume it's either granules or prills), then you can grind it separately from anything else in an oxidizer-devoted coffee grinder. A blade mill-type grinder will make it finely powdered in less than 30 seconds.
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