Ball Mill Safety

[javagamer]

My brother claims that it's safe to mill black powder indoors and he plans on doing this in a ball mill he's constructing. He's using non-sparking lead media of course, but I'm still worried that it's not a good idea. Most sources I found all say to NEVER mill inside and say to protect with sand bags or at least a large trash can.

He cites a video he can no longer find which shows how they test the jars so that in the event of an explosion only the lids come off.

I'm wondering what the members of this forum think and hoping I can find some sources that point one way or another.

Thanks in advance

[iNow]

When in doubt, kick him out. It's all well and good if he hurts himself, but it's not cool if he hurts others.

[javagamer]

Unfortunately we're both still in school (K-12) and we live with our parents, thus I can't kick him out. My parents are very reasonable though, so if I make a good case they won't let him do it. Just want to be sure I have all the sources I can.

[hermanntrude]

I imagine any half-decent parent would immediately forbid any child to mill gunpowder ANYWHERE, let alone indoors.

[javagamer]

If done properly (under a trash can far away from buildings on an extension cord) it can be entirely safe. He is legitimately doing pyrotechnics so my parents trust him a bit, however I don't think he's really going to reconsider safety until something bad happens and that's something I'd much rather avoid.

I don't think it will be a big issue once I mention it to my parents, but I just want to be sure I have stuff to back up what I say. They're very reasonable and I'm pretty sure this won't be a big issue.

 

I can be overly concerned with my safety at times so part of the reason I posted this was to be sure I wasn't worrying over nothing.

[John Cuthber]

Once he has done it outside a hundred times then you might think about saying it's safe enough to do inside.

[insane_alien]

My own rules on doing stuff with potentially dangerous substances(explosion hazard in this case) is do them outside, even if the operation is percieved as safe.

 

The thought process should follow the lines of

 

1/ For some unknown reason reality has contradicted the sheer force of my awesomeness and the damn thing is on fire(or whatever the worst case scenario is for whatever you are dealing with), what are the consequences of this.

2/ If the answer of this is, explosion, fireball, noxious fumes, sprays stuff everywhere etc etc then do it outside.

[CaptainPanic]

Your brother has thought of the risk, and came up with:

The chance of an ignition is small (it's never zero), and if it happens, I want to avoid an explosion. I will accept that there will be fire inside the house though.

 

And you say:

The chance of an ignition is unknown (but not zero), and if it happens, it should be outside and away from anyone (still without explosion).

 

That's quite simple, isn't it? You have to choose between those two.

 

Risk assessment in a nutshell

The definition of "Risk" is simple: Determine the chance (which is not zero), and determine the effect. Multiply the two, and be done.

 

Many people only focus on minimizing the chance, which is fine. But minimizing the effect can improve safety faster sometimes.

 

You can minimize the effect of an accident by doing it outside, or perhaps by reducing the amount of gunpowder in the ball mill.