Brightthermite Posted February 17, 2018 Posted February 17, 2018 I recently tried my hand at milling up some magnesium, as I was tired of filing it down. My mill, which is a rock tumbler with a rubber drum, produced some very fine powder. The powder is black and burns much fast then the filings do. However, to my surprise, I get very poor result using it for any kind of flash. The Mg filings give me a good thumb and a clean burn spot on paper when mixed 50/50 with KNO3 and even better results with sodium persulfate. The milled Mg is somewhat hard to ignite and will not thumb at all when unconfined, it will also set paper on fire. It burn quite a bit faster then flake smokeless powder but does not give a report like the filings do. Side note: the powder when burned releases a ton of air float black residue, if its oxide its much more then a equal mass sample of the filings leave. The powder also produces a lot more smoke then the filings when used in a compesition, so this leads me to believe the powder my be contaminated with rubber form the drum. Does anyone get a good report from flash that used Mg finer then filings? Also has anyone had any trouble with there rubber drums? I could use some insight, Im very curious.
cevmarauder Posted February 17, 2018 Posted February 17, 2018 (edited) I'm no expert by any means, but I gotta warn ya: Milling magnesium a bad, bad idea. Magnesium likes to self-ignite from ball milling--it's incredibly pyrophoric. Lloyd S. tells a story of a time he managed to blow a ball mill jar apart, temporarily blind himself, and get a nice set of radiation burns. He doesn't mention whether he needed new pants after the incident. If the legend who literally wrote the book on ball milling says don't do it...probably a good idea not to do it.It's just not worth it. And never, ever mill inside the house.As for making flash with it, you need it to be a helluva lot finer than filings. But it's wise to stay away from magnesium-based flash, too--it's way too touchy, prone to self-ignition, and really, there's no value-add over bog standard aluminum flash. Even if you try to passivate it.Keep your magnesium for your stars. Don't wind up a statistic and provide more ammo for the ninnies who want to make this hobby totally illegal. Edited February 18, 2018 by cevmarauder 2
Brightthermite Posted February 19, 2018 Author Posted February 19, 2018 I'm no expert by any means, but I gotta warn ya: Milling magnesium a bad, bad idea. Magnesium likes to self-ignite from ball milling--it's incredibly pyrophoric. Lloyd S. tells a story of a time he managed to blow a ball mill jar apart, temporarily blind himself, and get a nice set of radiation burns. He doesn't mention whether he needed new pants after the incident. If the legend who literally wrote the book on ball milling says don't do it...probably a good idea not to do it. It's just not worth it. And never, ever mill inside the house. As for making flash with it, you need it to be a helluva lot finer than filings. But it's wise to stay away from magnesium-based flash, too--it's way too touchy, prone to self-ignition, and really, there's no value-add over bog standard aluminum flash. Even if you try to passivate it. Keep your magnesium for your stars. Don't wind up a statistic and provide more ammo for the ninnies who want to make this hobby totally illegal.I know it should be much finer the filings for flash. Thats what leads me to believe that my powder has been contaminated, because filings are performing better then the powder is.
Sparx88 Posted February 19, 2018 Posted February 19, 2018 Not worth the risk or the cost of ruining mag. Oxidation is an enemy to be feared here. You may want to pm some of us instead if you want the answers you seek. Flash threads tend to be short lived when the answers one wants can be found by -searching- more. I know you don't want to hear that but then again there's no need to rush anything considering what it's about.
cevmarauder Posted February 19, 2018 Posted February 19, 2018 I know it should be much finer the filings for flash. Thats what leads me to believe that my powder has been contaminated, because filings are performing better then the powder is.You probably are grinding rubber off the sides of your tumbler. And that contamination may be the only thing keeping your magnesium from self-igniting the second you open the container. Oxidation is an enemy to be feared here.'Feared'. Not 'Respected'. 'Feared'. Magnesium will go pyrophoric and will maim or kill you. If you're going to continue grinding it, in light of all that, at least upgrade to a Sponenburgh-type mill with PVC jars, and set up a way of remotely opening and dumping the jars. There's been reported incidents of empty mill jars (with just a bit of dust in them) igniting from the impact of the milling media being loaded in for another batch. Stuff's just way too unstable for my tastes. Spend $20 and get a pound of Eckart German Blackhead aluminum.
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