psyco_1322 Posted June 7, 2014 Posted June 7, 2014 True, but it could be closer to impressive. Why don't you divert your time and energy into making some better rockets! Right now you are looking for a magical answer that doesn't exist. You should really just give up on this whole idea. A 1/2" or even 3/8" rocket will easily lift enough flash to be "impressive". Like stated before, it only takes a couple grams to really make some noise. If you were making nice 1/2" rockets, you could be attaching your shells as headers....or 50g salutes.
schroedinger Posted June 7, 2014 Posted June 7, 2014 OK, so pyrophoricity can be prevented by adding charcoal.No you can just slow it down, but prevent it
LiamPyro Posted June 7, 2014 Author Posted June 7, 2014 Why don't you divert your time and energy into making some better rockets! Right now you are looking for a magical answer that doesn't exist. You should really just give up on this whole idea. A 1/2" or even 3/8" rocket will easily lift enough flash to be "impressive". Like stated before, it only takes a couple grams to really make some noise. If you were making nice 1/2" rockets, you could be attaching your shells as headers....or 50g salutes. Good idea! Would a 1/2" rocket be enough to lift a 1 1/2" shell?
LiamPyro Posted June 7, 2014 Author Posted June 7, 2014 One last question about magnalium: How much charcoal would be added when milling, say per 100 grams of MgAl.
LiamPyro Posted June 7, 2014 Author Posted June 7, 2014 Also about the rockets: I recently made a batch of 60/30/10 rocket fuel and ball milled it overnight then finely granulated it without a binder.I have'nt had time to test it yet, and I was wondering if this is a recommended composition? I have tested the mix unmilled, and it was a bit slow and caused the rockets to have a lazy, arcing flight. What I am looking for is a powerful flight with a fairly straight trajectory.
LiamPyro Posted June 7, 2014 Author Posted June 7, 2014 No you can just slow it down, but prevent itAssuming you meant "not" and accidentally typed "but" instead, your saying that even with the charcoal coating it would still oxidize, just not fast enough to cause it to become pyrophoric?
TYRONEEZEKIEL Posted June 7, 2014 Posted June 7, 2014 Pastimepyrochemicals.com sells 3 micron magnalium Pastimepyrochemicals.com sells 3 micron magnalium
LiamPyro Posted June 7, 2014 Author Posted June 7, 2014 Cool! The finest I had seen before was 325 mesh.
LiamPyro Posted June 7, 2014 Author Posted June 7, 2014 The funny thing is their price for it is $18 a pound, whereas on eBay you can buy 325 mesh MgAl for $25 a pound.Makes absolutely no sense, the finer material is cheaper?
Mumbles Posted June 7, 2014 Posted June 7, 2014 No, Ebay just prays on people who don't know any better. You seem pretty convinced that adding charcoal will prevent oxidation. This is not true, nor how blackhead aluminum is made. There is no way to totally prevent or slow it if you're going to be milling MgAl. MgAl is very reactive, will happily react with oxygen, and is probably one of the most dangerous metals to mill due to how brittle it is and how readily is breaks down. Given some of the things you've said in this thread, I'd also advise not working with flash, especially the most sensitive varieties, until you gain more experience and knowledge in this hobby.
psyco_1322 Posted June 7, 2014 Posted June 7, 2014 That 3 micron Magnalium is pretty sensitive stuff too, way more than the 325 mesh. I personally have some of that and have made flash with it, it sucks. There is a reverse effect with magnalium and particle size. The very fine material actually makes slower flash. I would literally be a waste of your money to buy it. It's also not really suitable for any other formulas. A 1/2" rocket will lift those shells easy. I would suggest trying a 75:15:10 fuel, hand mixed, maybe with 2% mineral oil to keep the dust down.
schroedinger Posted June 7, 2014 Posted June 7, 2014 No the charcoal isn't enough to prevent it from becomming pyrophoric! The becommin pyrophoric part depends mostly 0on you milling time, and can sometimes be reached very fast. The charcoal or wax is only added to slow down that process and make it a little easier to controll, but the danger stays. Please stop thinking about doin this from what i read here, I'm not sure that you are capable of doing this process safely at the momment. If your magnalium is -325 get a 500 mesh screen and use this to sift out the fines from your magnalium and use that. Everything resting on top of that screen gets used for stars. For your rockets, noone will be able to help with tha informations you gave, it depends on what tooling are you using, end or core burner, dowel and drilling a hole in the plug, charcoal?? That fuel should be god for core burner (maybe allready too fast) but propably to slow for an endburner. Did you read the skylighter project plans for making rockets, they give you a good start?
LiamPyro Posted June 8, 2014 Author Posted June 8, 2014 That 3 micron Magnalium is pretty sensitive stuff too, way more than the 325 mesh. I personally have some of that and have made flash with it, it sucks. There is a reverse effect with magnalium and particle size. The very fine material actually makes slower flash. I would literally be a waste of your money to buy it. It's also not really suitable for any other formulas.I think the finer magnalium sucks for flash powder because the finer the particle, the more of it's total mass gets oxidized.In other words, 10 grams of super fine MgAl might only be 75% metal, while the rest is oxidation. I think the same thing is true for non-dark aluminum. If the oxidation could somehow be prevented, then it would probably work really well.
LiamPyro Posted June 8, 2014 Author Posted June 8, 2014 A 1/2" rocket will lift those shells easy. I would suggest trying a 75:15:10 fuel, hand mixed, maybe with 2% mineral oil to keep the dust down.Could I granulate it through a fine mesh screen without a binder to reduce dust instead of using mineral oil?
LiamPyro Posted June 8, 2014 Author Posted June 8, 2014 You seem pretty convinced that adding charcoal will prevent oxidation. This is not true, nor how blackhead aluminum is made. There is no way to totally prevent or slow it if you're going to be milling MgAl. MgAl is very reactive, will happily react with oxygen, and is probably one of the most dangerous metals to mill due to how brittle it is and how readily is breaks down.So, unlike aluminum, magnalium will oxidize no matter what?
Maserface Posted June 8, 2014 Posted June 8, 2014 Could I granulate it through a fine mesh screen without a binder to reduce dust instead of using mineral oil?Yes, you can use water or alcohol for that, just dampen like you would polverone and push through a fairly coarse screen. (A window screen works for me, or a kitchen strainer)
LiamPyro Posted June 8, 2014 Author Posted June 8, 2014 Instead of using magnalium, could I simply reduce the particle size of my aluminum in a ball mill to improve it's speed?
psyco_1322 Posted June 8, 2014 Posted June 8, 2014 (edited) Could I granulate it through a fine mesh screen without a binder to reduce dust instead of using mineral oil? Yes that would work also. Why do you keep insisting on milling shit to get it faster? It doesn't get any faster, stop expecting huge booms from tiny pinches of powder. Use 5-10g, you won't find anything under performing about it. Edited June 8, 2014 by psyco_1322 1
Jakenbake Posted June 8, 2014 Posted June 8, 2014 Just buy a pound of Ekart 5413 Dark AL and be done with it! For all normal purposes that's as good as it gets! Trying to mill it finer is just going to wear out your mill, jar and the media (not to mention all the hazards we have talked about)
LiamPyro Posted June 9, 2014 Author Posted June 9, 2014 Good point. I'm just going to buy some magnalium powder and call it good.
LiamPyro Posted June 10, 2014 Author Posted June 10, 2014 I know. I can be a bit stubborn to the point of idiocy. xD
MrB Posted June 11, 2014 Posted June 11, 2014 (edited) If your wanting to make Flash powder with MgAl , than you dont need to be making flash powder.Second your wanting to mill the MgAl to a powder wich is ridiculously dumb , Lots of accidents have happened when people mill MgAl.I've been making KNO3/MgAl flash for a while now. Mostly as a test to see how it compares with Perc/Al since Perc is going to be damn near impossible to obtain around here in a while. I've taken to making my own MgAl, and as such, i of course have to mill it. Starting out with a improvised furnace i upgraded to a unit where i can tip the pot and cast the MgAl in to a block, which as it turns out helps a lot with processing it. I simply stick the casted blocks in a different kind of mill then we usually think of, and cut it down to shavings. Shavings are then milled 1 hour at a time, 3 hour rests, 24/7 for a week, in a PVC "jar" with steel media. Once it's run for a week i just let it sit for a couple of days, after which i poke a hole in the plastic endcap, and leave it for another day. While it just "sits there" i manually fire it up so it spins a quarter of a revolution or so a couple of times every day.So far it's been no issues related to this, and i suspect the 1/3 approach isn't needed, i just had the timer for that available, and i doubt it hurts. I've been meaning to coat it, but for the time being i've only been using it for flash, and not storing it, so i haven't researched what i would coat it with, or how. Saying something shouldn't be done due to accidents that have happened is, well, the safe way, sure. But another way to go about it would be to try and find a safe way to do it. Inert gases isn't the way to go with MgAl, but at least for now it seams to work if you slowly let oxygen get in to the container and the MgAl just reacts with tiny amounts, without the crazy out of control reaction-speeds that is the real issue...B! Edited June 11, 2014 by MrB
LiamPyro Posted June 11, 2014 Author Posted June 11, 2014 I've been meaning to coat it, but for the time being i've only been using it for flash, and not storing it, so i haven't researched what i would coat it with, or how. Is commercial MgAl powder usually coated?
Shadowcat1969 Posted June 11, 2014 Posted June 11, 2014 I hadn't seen any commercial MgAl that is coated. My understanding is that you can coat it with potassium dichromate or linseed oil. I could be wrong, but those are what I remember.
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