AdmiralDonSnider Posted December 4, 2010 Share Posted December 4, 2010 Magnalium seems to be one of the most versatile metals used in pyrotechnics. However, the effects of coarse fractions of MgAl seem to be rather unknown in the amateur pyro community. I don´t know if this comes from the fact that coarse MgAl is rarely found in the stocks of pyro suppliers and thus rarely experimented with. Lancaster (p.114) mentions that "in coarse powder of about 30-50 mesh the metal produces a sharp crackling noise in coloured flame fountains. The presence of cryolite seems to enhance this effect." Coarse grades of magnalium crackle when burned and they do crackle on their own, without any need for additional chemicals such as in dragons eggs. The effect is a simple one and quite pleasing, not only in the fountains mentioned by Lancaster, but also in comets and other applications. The larger the particles, the louder the crackling, changing to a sizzling effect when finer fractions are used (which is noticable even with fine grades in colored stars). The effect of cryolite mentioned by Lancaster however is still unknown to me. I´d be thankful for some insight on the topic. Link to comment Share on other sites More sharing options...
Peret Posted December 4, 2010 Share Posted December 4, 2010 The effect of cryolite mentioned by Lancaster however is still unknown to me. I´d be thankful for some insight on the topic.Cryolite melts at around 1000C, and molten cryolite has the useful property of dissolving aluminum oxide. It wouldn't surprise me if that plays some part in the reaction. Link to comment Share on other sites More sharing options...
WSM Posted December 5, 2010 Share Posted December 5, 2010 Cryolite melts at around 1000C, and molten cryolite has the useful property of dissolving aluminum oxide. It wouldn't surprise me if that plays some part in the reaction. I think Peret is right. Other materials may have a catalytic effect also. I know if dragon eggs are made, a higher percentage of aluminum makes louder pops. Usually a mixture of magnalium and aluminum is used to achieve the optimal effect. Cryolite also includes fluorine which probably plays prominant role in fluxing as well as reacting with the metals. Some pyrotechnists also add copper oxide to their dragon egg effects. Course MgAl makes a dramatic effect in large comets, from "sizzling" to "crackling" as well as a fuller tail. WSM Link to comment Share on other sites More sharing options...
NightHawkInLight Posted March 2, 2011 Share Posted March 2, 2011 I'm bringing a thread back to life rather than posting a new useless one. What do you all think about this effect: http://www.youtube.com/watch?v=NK2MS2Yog0g&feature=related It seems to me that it's got to be a dragon egg matrix, but I'm not 100% sure. Pretty cool though isn't it? I'd love to have that comp in a few shells. Link to comment Share on other sites More sharing options...
Mumbles Posted March 2, 2011 Share Posted March 2, 2011 That looks to be a matrix comet to me. Coarse MgAl gives more of a sizzling than a crackling. It is a little hard to describe, but different from dragon eggs. Link to comment Share on other sites More sharing options...
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