AirCowPeacock Posted August 17, 2012 Posted August 17, 2012 Hey, I'm making some 1/4" cylindrical shell inserts for a multibreak shell I'm making. I want to do a colored flash. I'm pretty confident in my red Strontium Nitrate based flash, but I'm afraid it will offset the balence of the shell or go unnoticed (first break TT and Improved Firefly, second break Blue and Red (or maybe just one) organic stars.) I recently purchased some Barium Nitrate and was thinking a green flash--if briliant enough--would go both noticed and break harmony at the end (finalle.). On PyroCreations they list a green flash...this is it: "Green flash Source: rec.pyrotechnics Comments: Preparation: Potassium Perchlorate...6Barium Nitrate...3Aluminum powder...5" I wanted to know if anyone has success with this flash (being very vibrant and bright green) or if they have had success with another green flash not using Barium Chlorate. P.S. My Alluminum says: Bright Flake, coated, -325 mesh. Is this going to be a problem and should I add +0.5% boric acid?
AirCowPeacock Posted August 17, 2012 Author Posted August 17, 2012 And my shell inserts will be 1/4" cylindricals, the shell is 1.5" cylindrical (1.25" inch actual O.D.)
Seymour Posted August 17, 2012 Posted August 17, 2012 Even with the high temperature decomposition of perchlorate yielding some chlorine for Barium chloride, that flash is going to be a pathetic green. The Aluminium will wash out any green that manages to emit. It looks like a decent pale lichen like white flash. I'm sure it will go bang nicely, and will be a brilliant colour... but you'll get a brilliant off white. I've seen good results from Barium nitrate, Mg and a chlorine donor, though these flashes tend to be a bit less loud than regular flash, but at least the colour is unmistakeable.
AirCowPeacock Posted August 18, 2012 Author Posted August 18, 2012 Unfortunetly I have no Mg, do you think stociometric Barium Nitrate (decomp to Barium Nitrite? Or Barium Oxide?) Al + 5% to 10% Parlon would sufice? Or should I just go with red?
Peret Posted August 18, 2012 Posted August 18, 2012 I don't believe you'll ever get a green flash with barium nitrate. This formula from Hardt is supposed to give a good green: Barium chlorate 50Dark aluminum 25Antimony sulfide 13 (dark pyro, not Chinese needle)Sulfur 12 It is extremely dangerous.
Potassiumchlorate Posted August 18, 2012 Posted August 18, 2012 (edited) I think the 9:1 mix barium chlorate/shellac could be used as green "flash". It explodes when confined. Edited August 18, 2012 by Potassiumchlorate
mabuse00 Posted August 18, 2012 Posted August 18, 2012 've seen good results from Barium nitrate, Mg and a chlorine donor, though these flashes tend to be a bit less loud than regular flash, but at least the colour is unmistakeable. I found these to be unsuitable, to slow, and barely green. 48/48/4 Ba-Nitrate/Mg/PVC. Gives a white flash with a slight green tint... No wonder, decent green stars use up to 15% PVC and more. Maybe this can be cured by using more PVC/Parlon and partly substitute the nitrate for something more agressive - KClO4, or even KClO3. 've seen good results from Barium nitrate, Mg and a chlorine donor, though these flashes tend to be a bit less loud than regular flash, but at least the colour is unmistakeable. I found these to be unsuitable, to slow, and barely green. 48/48/4 Ba-Nitrate/Mg/PVC. Gives a white flash with a slight green tint... No wonder, decent green stars use up to 15% PVC and more. Maybe this can be cured by using more PVC/Parlon and partly substitute the nitrate for something more agressive - KClO4, or even KClO3.
Potassiumchlorate Posted August 18, 2012 Posted August 18, 2012 This one, maybe: Potassium perchlorate 43Barium nitrate 21Aluminium dark pyro 36 A better but also more dangerous flash would be one using potassium chlorate instead of perchlorate and magnalium instead of aluminium. Something like this maybe: Potassium chlorate 36Barium nitrate 21Aluminium or magnalium 36PVC or parlon 7 Note that this is a dangerous one.
mabuse00 Posted August 18, 2012 Posted August 18, 2012 This one, maybe: Potassium perchlorate 43Barium nitrate 21Aluminium dark pyro 36 A better but also more dangerous flash would be one using potassium chlorate instead of perchlorate and magnalium instead of aluminium. Why not pure Mg? Also I would not expect a great green from such a low barium content, and the perchlorate as the only chlorine donor...
Potassiumchlorate Posted August 18, 2012 Posted August 18, 2012 Oh, it isn't my composition, it's something called the green DEGN formula. For my own part I always use magnesium for flash except when I want more report than light, so to speak.
AirCowPeacock Posted August 19, 2012 Author Posted August 19, 2012 "I don't believe you'll ever get a green flash with barium nitrate. This formula from Hardt is supposed to give a good green: Barium chlorate 50 Dark aluminum 25 Antimony sulfide 13 (dark pyro, not Chinese needle) Sulfur 12 It is extremely dangerous." I'd go so far to say unsuitable for pyrotechnics due to instability. With Barium Chlorate, one could just use it with Al or Mg and it should be fine without sulfur(s.). Shouldnt it? Ill mess around with the KP chlorinated greens some otherday. I just used 70:30 KP:Al flash for the salutes on this shell (launched it tonight). Maybe Ill try green on some other.
Peret Posted August 19, 2012 Posted August 19, 2012 I'd go so far to say unsuitable for pyrotechnics due to instability. I didn't invent it, I quoted it from Hardt, the premier pyrotechnic formula textbook. You wanted a green flash formula, that's the only green flash formula in the literature.
AirCowPeacock Posted August 19, 2012 Author Posted August 19, 2012 I know, but Barium Chlorate mixed with Sulfur and Antimony Sulfide....sounds like a recipe for disaster.
Mumbles Posted August 19, 2012 Posted August 19, 2012 Formulas such as the one posted by Peret are prototypical of what you would expect to see in colored beraq. No they are not the safest compositions (clearly), but if you want that good color that is clearly what it takes. I'd expect to see a fine magnesium used in practice however. These types of effects are rumored to cause a majority of pyro accidents in Malta. For colored flash, magnesium is the best. It also must be protected as it will be attacked by the oxidizers. Dichromate is regularly used as linseed oil will retard the burn and make it less suitable. The more reactive the metal, the better the effect. Granular is better in this regard than atomized. It probably wouldn't be quite as good, but I bet magnalium could be used as well. Aluminum is going to be the worst, and require a good amount of chlorine to avoid completely washing out the color. Colored salutes are generally better in smaller devices. This also makes them a little safer to handle. The first formula PotassiumChlorate posted will almost without a doubt burn white, especially in larger salutes. Mixes very similar to this used to be used commercially to make the powder more dense. The second one might have some promise. If I were going to develop my own I'd be looking at a mixture of potassium perchlorate, sulfur, magnesium and barium nitrate, possibly with a chlorine donor such as saran or pvc. I feel like it should be possible to do without resorting to chlorates, but who knows for sure.
mabuse00 Posted August 30, 2012 Posted August 30, 2012 (edited) Hi, since I'm planning to do some tests with green and red flashs, can somebody please make a statement to this quotation: http://www.amateurpy...er/page__st__80 To get a nicely colored flame from flashpowders, the maltese often add a chlorine donor, mostly PVC. Parlon will not work as well, because it is a flame retardant. The reaction is so fast you need something that burns together with the other ingredients when ignited. This is especially true to get a good green from barium nitrate/magnesium flash. I was under the impression it's the other way around, PVC is much more retardant than parlon. Parlon stars burn much more vicious than pvc ones, even when dextrine bound...? Edited August 30, 2012 by mabuse00
Potassiumchlorate Posted August 30, 2012 Posted August 30, 2012 I have done some tests with just potassium chlorate+PVC vs. potassium chlorate+parlon. The mix with parlon burned much better.
Mumbles Posted August 30, 2012 Posted August 30, 2012 For me, saran by far burns the fastest and the cleanest. Comparing parlon and PVC can be difficult. I was always under the impression based on experience that PVC burned more slowly than parlon, however others have disagreed. It may in part come down to particle size. The majority of Parlon I've gotten was pretty fine, with the occasional chunks that I screen out. The PVC on the other had has been of a much larger particle size, and very static charged. The last part doesn't actually matter for burning behavior, it's just a pain in the rear, and is why I don't really use it. I've never actually tried a PVC and parlon comparison, side by side in similar formulas. It'd be interesting to try something like that. For what it's worth, all of Ralph Degn's colored flash formulas use PVC. I don't know if that was a performance or availability factor though.
AirCowPeacock Posted August 30, 2012 Author Posted August 30, 2012 Yesterday I spent several hours trying to make a good green flash with Barium nitrate without Mg. I did not succeed. I certainly didn't try all my ideas, but I kept ending up with the flash either being too slow or not green. I tried the formula at the top of the thread. It produced a very very bright flash, but a white flash--not green. I might try again, might not. I used both PVC and Parlon as a donor. Both--even at 5% slowed burn rate significantly--which surprised me.
Potassiumchlorate Posted August 30, 2012 Posted August 30, 2012 Yesterday I spent several hours trying to make a good green flash with Barium nitrate without Mg. I did not succeed. I certainly didn't try all my ideas, but I kept ending up with the flash either being too slow or not green. I tried the formula at the top of the thread. It produced a very very bright flash, but a white flash--not green. I might try again, might not. I used both PVC and Parlon as a donor. Both--even at 5% slowed burn rate significantly--which surprised me. None of them really burn very good but parlon burns better, at least my parlon does. It burns the best with a powerful oxidizer like potassium chlorate. The potassium chlorate is the primary chlorine donor anyway, so 5% should be enough. 5% parlon gives 3.5% extra total chlorine in the composition and also enlarges the flame.
mabuse00 Posted August 30, 2012 Posted August 30, 2012 You can get almost anything to burn with chlorate I think something like this could do the job: Ba(NO3)2 40KClO3 15Magnesium 35Parlon 10
AirCowPeacock Posted August 31, 2012 Author Posted August 31, 2012 What about using HCE or HCB as the chlorine donor?
WSM Posted August 31, 2012 Posted August 31, 2012 What about using HCE or HCB as the chlorine donor? Either would be (and have been) excellent chlorine donors, except, HCE is volatile and will vaporize out of the composition and HCB is highly toxic, banned and quickly becoming unobtainium. Too bad, too; because they're both effective in their own ways. WSM
pyrojig Posted September 1, 2012 Posted September 1, 2012 Either would be (and have been) excellent chlorine donors, except, HCE is volatile and will vaporize out of the composition and HCB is highly toxic, banned and quickly becoming unobtainium. Too bad, too; because they're both effective in their own ways. WSM Sadly they take all the good-ol-stuff off the market, protecting us dumb homo-sapiens from our selves. Could pvc or saran be subbed w/o adding too much fuel value? Im sure that it will require some tweeking .
AirCowPeacock Posted September 3, 2012 Author Posted September 3, 2012 Although not exactly flash, perhaps CuO/Al thermite would produce a green flash??
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