angelluis Posted November 16, 2012 Posted November 16, 2012 Hello everyone, I have been gone for a while due to financial problems. My question is will dark aluminum go bad if it has sat for about 2 years? It has been in storage and now when I mix it with my Potassium Perchlorate, it burns like slow flash at times, and takes about 2 to 3 seconds to ignite but doesn't have the same swoosh it had at first. Can my aluminum have some moisture ? The Potassium Perchlorate is new and has anti-cake in it but this was never a problem before. I have started building shells again and need it for my break to report shells. If it has moisture can it be dried some way or should I just buy some new aluminum I have about 3 lbs of it left.Thank you in advance for your help.
Potassiumchlorate Posted November 16, 2012 Posted November 16, 2012 I was thinking the same just today. I have some dark Al that I bought in 2010 or 2009. It used to be very powerful, but today it was lame, and that was an experimental amount of 2 grams chlorate flash The bottle was unopened until a few weeks ago, by the way.
spitfire Posted November 16, 2012 Posted November 16, 2012 Sounds rather strange to me, i got a large bucket with Dark from a friend, it must have been laying around in his garage for over 10 years. I think it must be about 15 - 18 years old now. Still bangs like crazy with perc...
StrikeAnywhere Posted November 16, 2012 Posted November 16, 2012 Just a few days ago, I tested a batch of FP with some 2 years old dark aluminum, and it seemed to work perfectly fine..
dagabu Posted November 16, 2012 Posted November 16, 2012 Interesting, I have some dark Al that the drum said was made in 1983 and I have had it now for four years and all of the salutes I have made with it and put on top of the rockets this fall worked as well as any others I have ever made with this Al. I do have it in sealed HDPE bottles, maybe that helps some. -dag
Potassiumchlorate Posted November 16, 2012 Posted November 16, 2012 I have never heard that aluminium should be prone to oxidation, at least not in the forms that you usually use it in. What I've learned in high school is that aluminium is oxidized on a few nanometers on the surface, and that the oxidation then stops. I have no idea why angellluis's and my aluminium behave like they do.
dagabu Posted November 16, 2012 Posted November 16, 2012 I also thought that dark pyro Al was coated. The only metal I have issues with is Mg, it can tarnish quickly. -dag
Potassiumchlorate Posted November 16, 2012 Posted November 16, 2012 Isn't wet potassium perchlorate very unusual? I have never experienced it. In my case it was potassium chlorate, and that was caked, although I have no idea whether it was moist or not.
Shadowcat1969 Posted November 16, 2012 Posted November 16, 2012 I too have some very aged Dark Al. I bought it around 1999 and it still bangs just as much as it always has. My Perc is about that old too, and I just made sure that it's milled down, diapered really well and "boom"!
angelluis Posted November 17, 2012 Author Posted November 17, 2012 Thanks to everyone for there replies, my aluminum was bought from Angie's aluminum it is 325 mesh dark pyro. They where sealed in the containers they came in which were blue. Also the potassium perc I just received about a week ago don't know what it could be. Well I guess I will be buying some better quality aluminum LOL.
Bcorso85 Posted November 17, 2012 Posted November 17, 2012 its almost like the aluminum clumped up during storage under its own weight. maybe it needs to be milled or screened down finer. It sounds like it is no longer a single digit or low number micron.
Peret Posted November 17, 2012 Posted November 17, 2012 I have some Angies, it does go bang, but there are better alternatives. I only use Star Molecule now for flash. Their stuff is fine as condensed smoke and out performs everything else I ever tried in small salutes..
mabuse00 Posted November 17, 2012 Posted November 17, 2012 I think aluminium can be stored forever. Look a these old WW2 plane wrecks the find sometimes.The iron ect. parts are mostly gone, but the aluminium is usually in good condition, even after 70 years. it is 325 mesh dark pyro.325 mesh is rather large, i think thats your problem.
Potassiumchlorate Posted November 17, 2012 Posted November 17, 2012 Hm, it might be the oxidizer then. Also, theoretically it should be 70% of potassium chlorate and 30% of aluminium, but that is for the pure metal. Maybe 66% potassium chlorate and 34% Al would be better. It was just an experiment anyway.
Algenco Posted November 17, 2012 Posted November 17, 2012 325 mesh as mabuseOO said is coarse for dark Al properly stored it should last forever. Although any oxidation would hurt any fine mesh metals
Potassiumchlorate Posted November 17, 2012 Posted November 17, 2012 Mine is <3µm or finer than 4000 mesh
angelluis Posted November 22, 2012 Author Posted November 22, 2012 Well I finally figured it out Bcorso85 was right , all I did was ball mill it for a while and problem solved. Thanks to everyone for all there help.
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