Merlin Posted June 7, 2015 Posted June 7, 2015 It is reasonable to use 70 perc and 30 bright aluminum flake with say 5% Titanium added to make a very intense flash/sparkle with little or no report for a 4 ounce BP rocket header?I dont have much room for a header say a 3/4 diameter salute tube added to rocket. I just want a visual effect to the end of flight with little or no boom. Any ideas?
nater Posted June 7, 2015 Posted June 7, 2015 (edited) If you want very little sound, just mix the Ti with BP and build the header with little confinement. When the header ignites, you will have a puff with a sprinkle of ti sparks. Flash will be loud, even with the small amount you have in a 3/4" tube as a header. This was a 3/4" motor tube slipped over the 1/2" motor, filled with about 10 grams of flash and capped with an end plug. https://www.youtube.com/watch?v=uYGVMa2IVrU Edited June 7, 2015 by nater
Wiley Posted June 7, 2015 Posted June 7, 2015 Ditto what nater said. Bright Al is still going to give you a bang, not a poof.
Wiley Posted June 7, 2015 Posted June 7, 2015 That could work. But if you use dark Al in your KNO3 flash, even putting a piece of tape over the top of it is usually enough to get it to go high order. I once took a thin-walled tube (less than 1/16"), capped one end with a square of gummed tape, side fused it, dumped in 15g of 2:1:1 made with dark Al that was left over from filling bottom shots, and capped the other end with another piece of gummed tape. To hear it go, you never would have known that it wasn't in a strong casing. All flash is flash, whether or not the word "slow" appears in its name.
nater Posted June 7, 2015 Posted June 7, 2015 I don't think any type of flash would be appropriate when no noise is desired. There are a few photoflash comps floating around, but most of those are not too beginner friendly. I would stick with BP and Ti. I have done it plenty of times and it is good for marking the end of the delay without needing to build a shell, add a lot of weight to the rocket or bring a lot of attention if you are staying low key.
Andres1511 Posted June 7, 2015 Posted June 7, 2015 If you have barium nitrate (attention, toxic) then you can make photoflash... They're in general not that powerful, but do emit a massive amount of light.
Merlin Posted June 7, 2015 Author Posted June 7, 2015 (edited) This is what I tried. Maybe it is not flash. I made up several salutes using Perc 70% and 30 bright flake aluminum. None of them exploded though confined. They just burned with an intense white flame. I see a formula listed as PGI Titanium salute which is 66 perc, 8 dark pyro, 26 bright flake al. +8 Titanium. I just basically left out the dark pyro. I tried couple others with 1 part dark pyro and got a pop like a lady finger firecracker. From what I have seen leaving out the dark al causes it to burn without exploding.I can try barium nitrate as I have some on hand. Thanks. There are a couple of formulas using Barium nitrate I can try. I just looked them up. Most of them use mg or mag/alumimum. I avoid Mg altogether as well as chlorate based formulas due to increased chances of accidental ignition. However, in looking up the nitrate flash I stumbled across this photoflash formula which is very close to my "experimental" one. Ellern photoflash 60 perc, 40 bright aluminum Edited June 7, 2015 by Merlin
nater Posted June 7, 2015 Posted June 7, 2015 I am glad you found something that works. Just be warned, the only time I have any type of flash burn silver is when it was poorly mixed. I don't know your method for mixing it, but I typically get a report no matter how light the confinement.
Merlin Posted June 7, 2015 Author Posted June 7, 2015 (edited) I am glad you found something that works. Just be warned, the only time I have any type of flash burn silver is when it was poorly mixed. I don't know your method for mixing it, but I typically get a report no matter how light the confinement.Thanks. I will be careful. It wont be a disaster if it did go bang. It is just will all the mortar shells I will be launching I wanted to cut down the sound effects if possible. When I mix flash powder I use the diaper method with no more than 40 grams total comp. Traditional 70/30 mixes fairly easily but the aluminum flake is a silver clumpy material very light weight and it does resist mixing using the diaper method but I know of no other way to mix. The Ellern photoflash 60 perc, 40 bright aluminum is basically what I am making and it appears by far one of the safer photoflash formulas. I know that bright powder aluminum will go bang but this flake doesn't seem to want to.That rocket you posted truly had a wicked end effect. Edited June 7, 2015 by Merlin
FlaMtnBkr Posted June 8, 2015 Posted June 8, 2015 It depends on your aluminum. If it isn't as fine as what others are using it won't perform the same. I have some bright flake that is hard to light, let alone make a bang unless there is lots of confinement. Then I have some other stuff that will easily explode, similar to American dark. And to look at them they look the same, so it does depend on your material. You can take granulated BP and dust it with dark aluminum to make it a bit more potent. But with confinement it can get darn loud. I know a guy that made a commercial line of shells that did this and had the CPSC get on him because they thought they were overloaded with flash when they had none. At least that was the story though it does spice things up. If you want to make things bright without making a lot of noise then maybe add some magnesium powder to some slow BP.
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