Wiley Posted July 4, 2014 Posted July 4, 2014 So today, in anticipation of the big beautiful holiday that is now just about 45 minutes away, I lit a few small 1.75" aerial salutes. I shot some ball shells made with plastic hemis reinforced with strapping tape as per Ned Gorski's instructions for color shells. I also shot a couple cylinders with hand rolled chipboard casings and spiked with 16 verticals of doubled up 3# crochet thread. The balls used 15g of comp, and the salamis had 30. They were all made with the binary method using 2:1:1 KNO3:S:Eckart 5413. Though I'm sure it's not as noisy as perc base report comps, it's still quite serviceable and definitely can make some noise if properly confined. Now here's the issue. I shot one ball and one cylinder side by side to compare them. They both went almost exactly the same height, but there was almost no noticeable difference in noise. What do you think could be causing this? I was a little bummed because I'd spent a bit of effort making those cylinders, not to mention the apparent waste of chems and materials. I'm switching solely to balls now since they are so much simpler to make, and it looks like bigger is not always better. I do have a couple 2.5" mortars and some 2.5" balls coming in the mail, and I'm curious to see how one of those compares to a 1.75" 15g ball. I'm guessing that I'll be able to fit 30-40g in the 2.5."
mabuse00 Posted July 4, 2014 Posted July 4, 2014 (edited) I think thats for some degree caused by the characteristic of the human ear.If you double the energy in a wave that hits your ears, you only feel a slight increase of volume. You will need to make much larger charges to make people feel the difference. I like salutes that are very large and very far away. The sound is powerful but pleasant. From small distances the high pitched sound dominates and if you make it louder it just hurts. edit:fixed my spelling Edited July 4, 2014 by mabuse00
Wiley Posted July 4, 2014 Author Posted July 4, 2014 (edited) How much larger is "much larger?" The strange thing is, I lit a number of small ground salutes with this comp in order to better understand how much confinement it needs, and the difference between 20g and 30g was huge. The difference between 30g and 100 was also very noticeable, but not 3 times louder. Still, you could feel that one all over from 200ft away. I know you can fit almost 100g in a 2.5" if you settle both hemis full, though I'd prefer to stick with the binary method if at all possible. The main limitation with it on a ball is that I can only get the shell about half full, whereas in a cylinder, I usually fill them about 3/4 of the way full. Keep in mind too that this mix just burns with a whoosh in open air, so putting a massive amount in a thin casing isn't going to do much. Edited July 4, 2014 by Wiley
pyrokid Posted July 4, 2014 Posted July 4, 2014 I'd abandon the plastic hemis. Increases in noise can be had by switching to KClO4.
Wiley Posted July 4, 2014 Author Posted July 4, 2014 I understand that I'll get better noise with perchlorate, but for me it is double the money than nitrate: $10 per pound for perc and only $5 for nitrate. That, and perchlorate compositions require at least 16% more oxidizer than does the nitrate one. Though if it really is worth it I might give it a try.
hindsight Posted July 4, 2014 Posted July 4, 2014 I think thats for some degree caused by the characteristic of the human ear.If you double the energy in a wave that hits your ears, you only feel a slight increase of volume. You will need to make much larger charges to make people feel the difference. I like salutes that are very large and very far away. The sound is powerful but pleasant. From small distances the high pitched sound dominates and if you make it louder it just hurts. edit:fixed my spelling Totally agree. Weber showed that hearing is on a logarithmic scale, hence the use of decibel units. And lower frequencies travel farther through fluids. A large, distant salute is more appealing to me, too.
nwpyro Posted July 5, 2014 Posted July 5, 2014 Ugh... Nitrate Reports are a waste of Dark Al! I can make granulated black powder which makes better reports than nitrate F.
JimWoodson Posted July 5, 2014 Posted July 5, 2014 I just tried a mix of KNO3 and some mesh 350 aluminium powder and it wouldn't even ignite but my nitrate is not very fine
Wiley Posted July 5, 2014 Author Posted July 5, 2014 The 50g salami reports I fired at the end of my show were pretty loud; quite a bit more so than the commercial 60 canister shells I was firing. Plenty bright too. I'll upload some videos shortly so you can see what I mean, but they weren't as noisy as the 2.5" or 3" salutes in the professional display.
Wiley Posted July 5, 2014 Author Posted July 5, 2014 The 50g salami reports I fired at the end of my show were pretty loud; quite a bit more so than the commercial 60 canister shells I was firing. Plenty bright too. I'll upload some videos shortly so you can see what I mean, but they weren't as noisy as the 2.5" or 3" salutes in the professional display. If you guys think that a 50 dollar order of KClO4 will radically change my audience's viewing experience, I may give it a go.
MrB Posted July 5, 2014 Posted July 5, 2014 The 50g salami reports I fired at the end of my show were pretty loud; quite a bit more so than the commercial 60 canister shells I was firing. Plenty bright too. I'll upload some videos shortly so you can see what I mean, but they weren't as noisy as the 2.5" or 3" salutes in the professional display.Perchlorate salutes most likely. Also, confinement.B!
Wiley Posted July 5, 2014 Author Posted July 5, 2014 (edited) Here are some videos. 1.75" Salami (50g 2:1:1)https://www.youtube.com/watch?v=vtBkQ7Zbj4k&feature=youtu.be 1.75" Noise Comparisonhttps://www.youtube.com/watch?v=hd7qF7eVD9U&feature=youtu.be Finale with a 30g salami followed by a 50g salami with a little too much visco on the leader.https://www.youtube.com/watch?v=5dGYR3JPAjc Edited July 5, 2014 by Wiley
Mumbles Posted July 7, 2014 Posted July 7, 2014 One word of caution. Handrolled chipboard salutes are really designed to be filled to the brim, which prevents the use of the binary method. They derive some of their structural integrity from being full. It's one of these things that you can get away with in small sizes, but not in larger, just so you know. It's hard to give you definitive answers on this. You may want to pick up a little perchlorate for a side by side test to see if it's worth it. It's a very useful chemical for stars any way. It's also very hard to judge from videos, but they sounded loud enough. At a certain level salutes really don't get much louder. They just hit you in the chest harder, and are harder to look at. To me, the second video seemed like it had more rolling echo, which is in line with this phenomenon. You may also want to try pre-mixed flash vs. binary. In my experience binary salutes really aren't as loud.
Wiley Posted July 7, 2014 Author Posted July 7, 2014 (edited) Yes, they do have a nice echo to them if there's no wind, as there is in the first video. Still, they were not a noisy or concussive as the 3" chinese ball salutes that the pros fired in there show, which was just a short distance away. I understand that this type of salute is typically settled full, and that is exactly what I intend to try next, hopefully this weekend. That shoot site is over a mountain lake, so the echo is really something. Those "heavy" salutes were 4" long and held 50g of comp, but settled full I'm hoping to fit at least 80. Even at 50g, they're louder than the premium 60g color shells, so they should be just about loud enough when filled all the way up. This composition is by no means weak, though I've never done a side by side test with perchlorate. I may buy a pound just to test it out. Just as a better example, here are a salute chain and a single ground pound salute fired at the end of a friend's July 5th display. The chain had four 8g, five 15g and one 30g. The single salute is 50g, and cratered the ground even suspended about 2 above it. The chain: https://www.youtube.com/watch?v=HlrDsm-zUFQ Single salute: https://www.youtube.com/watch?v=X3Us3vXM7wQ You can clearly hear the echo roll away into the hills. From that distance, the shock wave was quite spectacular, and the crowd loved it. Its just that when you put that same amount up in the air 100 feet or so, it loses a lot of its edge. In the photo below, you can see how thick the casings are: about 3/16." Do you think it would be better to go for more wall thickness? The shells fit a commercial gun perfectly the way they are, so I'd have to roll them on a smaller mandrel. The one I'm currently using is 1.25". Edited July 7, 2014 by Wiley
psyco_1322 Posted July 8, 2014 Posted July 8, 2014 (edited) I think it's just the nature of nitrate flash to be crappy. Where perchlorate based flash doesn't really care much about the casing, the nitrate flash relies on the casing to develop noise. I'd also call nitrate flash a waste of Al....and nitrate. Edited July 8, 2014 by psyco_1322
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