bogey1 Posted June 2, 2009 Posted June 2, 2009 does anyone know how much gun powder it takes to reach critical mass? flash i think is a few grams to a half ounce.
Aneantis Posted June 2, 2009 Posted June 2, 2009 Depends on what kind of flash.And It takes a lot of blackpowder to reach critical mass, more then you can make.
popi1955 Posted June 2, 2009 Posted June 2, 2009 potassium chlorate and aluminum?? extremly well made
Mumbles Posted June 2, 2009 Posted June 2, 2009 Gun powder = black powder. The "critical mass" as you put it is around 500lbs. Flash is indeed much lower, and as others have pointed out is dependent on formulation and quality of mixing.
bogey1 Posted June 2, 2009 Author Posted June 2, 2009 yes, black powder not gun powder. i also heard it was 500lbs. thanks for refreshing my memory.
Mumbles Posted June 3, 2009 Posted June 3, 2009 The mass where a pile of composition will self-confine and explode on it's own.
marks265 Posted June 3, 2009 Posted June 3, 2009 The mass where a pile of composition will self-confine and explode on it's own. Ok so what's a pile. Do you take 500 pounds of powder and put it in a column that is 1 square inch as high as 500 pounds will go and then multiply by 1 bar or maybe 1 atmosphere or possibly 14.7 psi? I really need to know this for when I get to storing that much powder LOL!
Seymour Posted June 3, 2009 Posted June 3, 2009 When you store it it will be confined. It will pose an explosion hazard. You can only act to avoid it igniting in the first place.
TrueBluePyro Posted June 3, 2009 Posted June 3, 2009 Well as aneantis said, it depends on the flash, I know that nitrate flash wont self confine with only a few grams but kclo4 flash will with only a few grams. Not sure about others
Seymour Posted June 3, 2009 Posted June 3, 2009 Do not forget the metal powder variation... Not just particle size, but what metal is used.
TrueBluePyro Posted June 3, 2009 Posted June 3, 2009 yeah. Just thinking about this, this might be a cool thing to try and test out, like how much flash it takes till it will self confine, but do it with different oxidizers and different grade Aluminuim, I could make nitrate/al/s flash and kclo4/al flash and test it with my indain dark flake, 2-3 micron, about 300-400 mesh (I dont really know what mesh) atomized al and maybe some bright al, anyone else want to contribute to this? seems like a good idea? cause I scared the crap out of my self when I lit a pile of kclo4 flash (about 3-5g, I was just getting rid of it....)
Mumbles Posted June 3, 2009 Posted June 3, 2009 If you do, I'd suggest posting it on another website.
TrueBluePyro Posted June 3, 2009 Posted June 3, 2009 (edited) yeah sure, I just thought it would be a good idea for everyone to know (or we could ,shh, put it in the...HE section..shh), you dont have to knock it, like i know you dont like me, just you dont have to be a bitch about it, I was just suggesting it. What would be wrong about that, I wished I knew how much flash it takes before it self confines cause i started off making nitrate and then I tried kclo4 and it made a huge difference, I wouldnt go over alteast 10-20g flash, just saying I wished I knew before I made the stuff, maybe it could even go in the safety section or even the "test post" section or do I have to HE? I dont know. what ever, I'll take it to a nicer place. Edited June 3, 2009 by TrueBluePyro
Miech Posted June 3, 2009 Posted June 3, 2009 Just don't try. Leave experimenting with large amounts of flash powders to the pro's. In some cases not knowing is better than getting to know. From several sources several different critical masses are reported, but I believe 70/30 selfconfines somewhere around 40 to 50 grams. This means, when you make such a quantity and light it, you'll get a typical detonation shockwave. Smaller quantities pop and crackle, but are still deflagrating, having a more rounded off shockwave. Even the slightest confinement, like putting it in a bowl or laying a piece of paper on top of it, will reduce the amount needed for detonation dramatically. Detonation is probably not the right word, but it comes close.
TrueBluePyro Posted June 3, 2009 Posted June 3, 2009 (edited) Yeah I see now, I probs wasnt going to try but, who cares I found out my self anyway. My flash, with just a few grams, makes more then just a "pop" or a "crack" it was ringing in my ears for ages and ecoed for a fair while. as I said before very scary stuff. Thanks for the advice rather then just telling me off. Edited June 3, 2009 by TrueBluePyro
Swede Posted June 3, 2009 Posted June 3, 2009 1/2 a gram in a tiny ziploc, lightly folded 3 times, was all it took to convince me not to mess with FP outside of known uses as burst or aerial salutes. It is potent stuff.
Arthur Posted June 3, 2009 Posted June 3, 2009 Back in the days of yore, I disposed of half a pound of commercial flash in one shot, almost silently. It was BRIGHT though. Simply I spread it over a huge area til there was omly a very light dusting all over -talking of 30ft square here! With modern flash in a heap self containment can cause detonation at well less than a gramme think 25 milligrammes if the flash was good. Any experiments on this forum with flash will focus moderation on your case rather quickly.
TrueBluePyro Posted June 3, 2009 Posted June 3, 2009 ......Any experiments on this forum with flash will focus moderation on your case rather quickly....... What is that meant to mean? Its not like I am going to do it, and I'm not some kewl, I would know what I am doing, but I just thought that flash could self confine, in atleast under 10g, cause I dont want to make that much just to light on the ground, rather put it in a airal shell, otherwise known as airal salute. lets just forget about this topic.
TheSidewinder Posted June 4, 2009 Posted June 4, 2009 .......lets just forget about this topic. Since the OP's question has been answered, yes, lets.
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