Blaster5337 Posted December 2, 2014 Posted December 2, 2014 Thanks. I have some Chemistry knowledge, probably not enough yet! But "g/mol" did clarify the whole O2 content thing.
Blaster5337 Posted December 2, 2014 Posted December 2, 2014 Sorry! I keep coming up with more and more questions! For example, our sodium nitrate and hygroscopy discussion has returned my thoughts back to nitrocellulose lacquer, and or alcohol for the production of sodium nitrate in efforts to reduce hygroscopy? Hopefully, my curiosity and intrigue isn't getting on anyone nerves. You can't find good discussion like this just anywhere!
r44astro Posted December 23, 2014 Posted December 23, 2014 I just tried some 75/15/10 no binder using red cedar 3 hours in ball mill. I had read somewhere it is fast. I Granulated with acetone. 10 grams under a 145 gram baseball was 5 seconds from top to hit ground. The best I have made so far.
schroedinger Posted December 24, 2014 Posted December 24, 2014 I just tried some 75/15/10 no binder using red cedar 3 hours in ball mill. I had read somewhere it is fast. I Granulated with acetone. 10 grams under a 145 gram baseball was 5 seconds from top to hit ground. The best I have made so far.So are you talking about 5 seconds after apoge? If yes your bp is fast enough and even it is the whole time of flight, it is god enough.
r44astro Posted December 24, 2014 Posted December 24, 2014 Yes I timed from apogee. Did not time whole flightbill
Mumbles Posted December 24, 2014 Posted December 24, 2014 Sounds like you have a winner then. Depending on your application, I think you'll find that a binder will be helpful in the future. Granulated BP needs to be somewhat resilient to hold up for lift and bursts. Also, if you do time the whole flight, it's pretty easy to figure things out. When accounting for all the real world effects (air resistance, terminal velocity, etc.) it breaks down to about 1/3 rise time 2/3 fall time. So if you have a total flight time of 9 seconds, you can pretty safely approximate it to be a 6 sec fall time.
r44astro Posted December 24, 2014 Posted December 24, 2014 Thanks for feedback. Did some more test today, but my baseballs usually land in pond so they weigh 170 grams now. 12 g BP total flight time 11 secs. I am using a small paper bad to hold powder under baseball.Thanks again
schroedinger Posted December 24, 2014 Posted December 24, 2014 With that timing you can be sure to got good bp.
r44astro Posted December 27, 2014 Posted December 27, 2014 For what it is worth this is way I have found to be true for me. Coffee grind KNO3 for 20 seconds or more, you want flour. Ball mill red cedar chip charcoal (I get mine from TSC) until air float, less than an hour. I do not do anything to Sulfur. I use 75/15/10 no binders. I am presently using Harbor Freight Ball mill. 1/3 full of hard lead. Then the traditional 94/19/12.5 mix no binder. Mill for 2+ hours. I have found if I mill 3 to 4 hours I get caking but It does not seem to make any difference, so a waste of time I guess. I have tested the hard balls of BP from mill and they perform just as granulated. I read on this forum or (I think Fireworking.com )another to granulate with denatured alcohol, then dry quickly. The grains are quite hard even with no binder. Just tested 145 gram baseball out of 3" PVC (I know PCV a no no but only baseball, no stars, reports, and end cap just pushed on). With 8.7 grams of this powder wrapped in a piece of craft paper ( no granulation) I relized 9.2 seconds measured of flight time. Also I was suprised these grains were quite hard if dried quickly. I am only a beginner only my 2 cents worth. What I have also gleened is the KNO3 needs to be floured. The Red Cedar charcoal is fast and needs to be milled before. Anything over 2 hours (at least here in Florida high humidity) causes caking but I am not sure. In my exsperience witch is limited, this powder is very fast.Bill
rogeryermaw Posted December 27, 2014 Posted December 27, 2014 Pvc is a no no indeed. Its not the stars flying at you so much as the sharp shrapnel that doesn't show up on x-ray...... http://www.amateurpyro.com/forums/gallery/image/2832-pvc/
r44astro Posted December 27, 2014 Posted December 27, 2014 I guess what I met was I did not think I'd ever put enough BP in under baseball to cause problem.. Famous last words I suppose.
pyrojig Posted December 28, 2014 Posted December 28, 2014 Pvc can be found via xray now, but it is a poor choice of material for a firing tube. If one feels the need to use pvc, you could safely bury it . This way if a failure happens then it is contained in the ground and fragments will not fly .
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