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Safety of Alumina milling media


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#41 CrossOut

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Posted 19 June 2016 - 01:10 AM

You miss the point where you can test your media to be certain of its non sparking properties and i have yet to see any articles of incidences which show alumina media was the direct cause.  Yes, I know that just because it has yet to happened does not mean it cant happen. but i will still argue that records dictate it's safety backed by its physical properties of properly tested and used alumina media.

 

additionally if you want to regard "probably safe" as not being good enough for pyro you better toss the idea of using a ball mill for BP manufacture out of the window as it is probably one of the the least safe commonly used methods of manufacturing BP. 

 

Industry standards in china require the use of a roller mill which motion and friction is kept at a minimum and the use ball mills are prohibited for BP production. 



#42 MrB

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Posted 19 June 2016 - 02:45 PM

 

You miss the point where you can test your media to be certain of its non sparking properties

 

 

No, i just don't agree with you on that "testing" can be done in a meaningful way, that will provide results accurate enough to live with.

 

 

 

Yes, I know that just because it has yet to happened does not mean it cant happen. but i will still argue that records dictate it's safety backed by its physical properties of properly tested and used alumina media.

 

Great, then we can end this. All i ever was against was the "fact" you provided, that ceramic media was inherently none-sparking, even if limited to "mostly" Al₂O₃ media variants.

 


additionally if you want to regard "probably safe" as not being good enough for pyro you better toss the idea of using a ball mill for BP manufacture out of the window as it is probably one of the the least safe commonly used methods of manufacturing BP. 

 

 

Again, i have no problem with people using what ever they want, i just don't agree with the "fact" you provided. Encouraging use of ceramic media for milling BP may or may not be a good idea. I use lead, and recommend it, others use ceramic, and recommend it. But any recommendation should come with full disclosure. Ceramic media can only be considered non-sparking, if the manufacturer says it is, and provides the specs on the media. Second hand media is at best a guess as to what it was to start with, and what it has been used for since then. To some extent it can be cleaned, but your still in the unknown where it comes to it's sparking properties. Recommend a testing procedure that you think is good enough to provide the test results you feel comfortable enough to risk someone elses life on, and let them make the call them self, and i'll be fine with your recommendation for ceramic media, but stating as a fact that Al₂O₃ media is non-sparking, and i have to disagree.

I was pretty clear with this early on:

 

 

It's a simple fact, "Ceramic" alumina media has been in BP mill detonation, where as other, known not to spark, media hasn't. It's still generally considered a "safe enough" media, IF you can confirm that the manufacturer claims it's none-sparking. Which, point made here, not all media are. Second hand media? All bets are off. You have no idea what the specifications for the media was when it was brand new, and you have at best a vague idea what it's been used to mil since then.

 

 

 

We are all involved with a hobby that can quite easily kill us, or someone else. Stating false facts, isn't going to help us live longer.

B!


Edited by MrB, 19 June 2016 - 02:48 PM.


#43 CrossOut

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Posted 20 June 2016 - 12:43 AM

You have yet to provide any "facts" against my argument. Only conjecture. The only facts which have been brought up are by yours truly.

You argue that testing can not be done in a meaningful way which can produce reliable results? Seriously? If a guy can't preform reliable tests then he probably shouldn't be a pyro. The whole process of being a pyro relies on on testing, research, and improvement. That is why we are on this forum to ask questions, find answers, and share data.. I realize there are several who shouldn't be a pyro but now you are belittling the entire community. Honestly this is the basic scientific method! I'm sorry if you can't devise a method which can yield reliable data but don't assume others can't.

You seem to be using your argument against you're self now. I never once said the media was 100% safe. I simply recommended it. Stating that it is a commonly used non sparking media and is safe to use. Just as many have repeated the same for other varieties of media.

And for good sake stop saying ceramic media.. my argument was never about general ceramic media but specifically alumina media. (Its on the forum topic) Yes there is a difference and yes it is just as safe to use as lead When handled properly. If you disagree show me the data. Please find me irrefutable evidence of a high alumina media which produces sparks. I'm asking you to PROVE me wrong not post another argument about your opinion. So far all I've heard is the the words "false" and "wrong". No data, no evidence,only conjecture.

Edited by CrossOut, 20 June 2016 - 12:47 AM.


#44 MrB

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Posted 20 June 2016 - 03:50 AM

 

You have yet to provide any "facts" against my argument. Only conjecture. The only facts which have been brought up are by yours truly.

 

 

I don't really have to. You stated, as a fact, that Al₂O₃ media is non-sparking. It's not, and if anyone has to "prove" anything, then that is you. It's your "fact".

 

 

And for good sake stop saying ceramic media..

 

 

Why? It's the correct term. You want to be more specific, say Al₂O₃- or Aluminum Oxide- based ceramic media.

 

You argue that testing can not be done in a meaningful way which can produce reliable results? Seriously? If a guy can't preform reliable tests then he probably shouldn't be a pyro. The whole process of being a pyro relies on on testing, research, and improvement. That is why we are on this forum to ask questions, find answers, and share data.. I realize there are several who shouldn't be a pyro but now you are belittling the entire community. Honestly this is the basic scientific method! I'm sorry if you can't devise a method which can yield reliable data but don't assume others can't.

 

 

Right. Lets try reading what i said, and in the context i said it? Since a spark capable of ignition doesn't have to be possible to see with the naked eye, for a number of reasons, you just cant reliably test for it in a improvised environment. It has nothing to do with the scientific method, or the average pyro's ability.

B!



#45 stix

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Posted 20 June 2016 - 05:47 AM

People take a stance and then don't easily want to move from it, but facts are facts - right?

 

Surely it can be agreed upon that if you aren't sure of the quality and properties of your media, then it should be viewed as suspect.

 

There are relevant points from all sides that I agree with. I suggest that real tests need to be done using various media. I'm surprised that this sort of definitive testing, rather than anecdotal, has not been done before.

 

A relatively simple testing apparatus would be to swing from a pivot point (like a pendulum) various media smashing into each other with a bp coated substrate between. Start with the most likely (sparking steel, glass etc) then work it up from there. If it doesn't produce results (ignite) then go Mythbusters style and amp it up - flash perhaps?

 

It would also be useful and interesting to know the statistics related ball mill accidents using "non-ceramic" media.

 

I think there's something there for everyone if you look for it. :)

 

 


I just start the conversation - someone else has to question them.


#46 otto

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Posted 20 June 2016 - 03:47 PM

Surely it can be agreed upon that if you aren't sure of the quality and properties of your media, then it should be viewed as suspect.

 

 

I'd say that's great advice. I just bought into a good amount of zirc-M media that is generally accepted as safe from a sparking perspective. Since it was used I figured it required a thorough washing before my use. Once washed and dried I picked through the pile after finding a heavily rusted piece. I found another dozen or so of those AND what appeared to be a steel BB. 

 

Imagine the issue that might have caused......



#47 DavidF

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Posted 20 June 2016 - 09:11 PM

Crossout- respectfully- I don't think you are looking at this the right way. Even if you 'prove' to yourself that high alumina media is safe, what then? Will you ballmill black powder in your shed or basement, because it is safe? I'm just asking. I ballmilled BP in my shed, 2X750 gram loads. I thought I was being pretty safe. But when I made a 100 gram maroon with the mill dust, my attitude changed! I then realized that if my mill went BOOM for any reason at all, it would have destroyed the shed.

All black powder milling should be done with the assumption that the mill will explode. An unexpected mill explosion could ruin your life or kill somebody. Think of it this way: black powder plants and fireworks factories explode fairly often. These are people that know more than we do (at least more than I do)and they still have explosions. That's why there is only one black powder factory left in the whole US.

Lead is known to be non-sparking, and it is not hard. Would it be safe to mill with lead with no barricade? I certainly wouldn't do it. A bit of steel in the charcoal, rocks in the saltpetre or sulfur, dirt, there are just too many things to consider to say that ballmilling black powder is safe. Sure, it's safe. Right up until the second that it isn't.

I have been working on alternative methods for making black powder. It's certainly not everybody's cup of tea, but I use very small 304 SS media to mill my charcoal to a degree of fineness that is impossible with any other media. Yes this is a bold statement. I have milled charcoal and black powder with ceramic (high alumina), brass, lead, and stainless steel.

My tests have shown me that I can make screen-mixed black powder that rivals most milled powder. Also, in apples to apples comparisons, my home powder beat Goex. When I say 'apples to apples', I mean that my powder was pressed into pucks of a density of +1.8g/cc. It was then corned and graded to size. When used to launch baseballs, 10 grams of my powder (+-.01 gram) gave a flight time of 11 seconds. 10 grams of Goex gave 10 seconds. My 2FA sized grains tied with Goex 1Fg. 1Fg is the coarsest I can get up here.

I'm in the early stages of my testing at this point. I've already tested my powder in end burners, nozzleless rockets, and now with baseballs. Next will be with meal-coated rice hulls. I'm working on reducing the 'Yeah buts'. I also plan to use the same media in a modified Lortone mill to see how close I get to the more than acceptable performance I already enjoy.

Just another way to skin the cat. Don't flame me, BP millers! Almost all of you will never have a mill explosion ;)

#48 redbullzuiper

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Posted 04 January 2023 - 07:04 PM

We are now 6/7 years later. I had good fun reading this topic.

I respect both parties in this and also CrossOut for his input. Although at some point people bacame a little childish towards each other.

The fun thing is, crossout was pretty much right about alot. Many, really many use ceramic and spark resistant steel as milling media these days.

Lots of new topics and tests have been opened and conducted in those years
Its good to have such discussion, as years afterwards you can still read the debate :)




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