Ballmilling BP - To wet or Not to wet?

[pyrosailor99]

I've read so many things about ballmilling theory that my head became like a balloon.

 

the question is:

to have a decent meal powder (good for any use, from BP to lift etc) and make the BP in the 'safe' way, should i wet the BP inside the jar?

 

someone said i should for safety, but the same person said he can't obtain directly BP but granules that he have to dry and then mill again to have BP for black match...

somone else said this is not a need.

 

I've also noticed many of you suceed in having BP for liftcharge with rounded grains... and for this i think that grains are made with very few (or no) dextrin added to a wet composition in a ballmill...

[spitfire]

Milling wet is of course safer, although i always mill dry. I tried milling wet once, but it gave me poor results and cleaning the mill with loads of water.. To avoid any problems with static electricity i only run the mill on very humid days, i prefer pouring rain and foggy circumstances. One pyro i used to know years ago got himself killed when he pored his mill with 5kg fresh and dust dry BP onto a screen on a cold dry winters day (those are the sparkiest ones). Somehow it ignited and he died few hours later from the burnings. He left behind his wife and a 4 year old daughter. That has been an important lesson for me, and should be for everyone. My media is made of lead balls, 1'' in diameter. My BP always contains 4% dextrin for binding. Some is used for lift, some for rockets, some for fuse, etc etc. After milling i just wet it slightly, just enough to activate the dextrin, and push it trough a course sieve by hand. This is dried (within one day at room temperature) and used right away as lift charge. Pressing and corning is done by many, but i don't see the need for that. For example, when i test 1'' comets from a stargun i just dump in some lift charge, dump the comet on top and light it. The lift charge is powerful enough to shoot the comet sky high. No need to use paper wadding or cardboard on top. For me, that is an indication the lift is good enough.

[50AE]

I truely prefer riced BP because of the ease to make, but If I had the equipment for efficient corning, I would go with it. Corned BP burns the best from my experience, it does it cleanly, without leaving the white shit and orange sparks like riced BP does because of the KNO3 recrystallization. Edited October 3, 2011 by 50AE

[pyrosailor99]

Milling wet is of course safer, although i always mill dry. I tried milling wet once, but it gave me poor results and cleaning the mill with loads of water.. To avoid any problems with static electricity i only run the mill on very humid days, i prefer pouring rain and foggy circumstances. One pyro i used to know years ago got himself killed when he pored his mill with 5kg fresh and dust dry BP onto a screen on a cold dry winters day (those are the sparkiest ones). Somehow it ignited and he died few hours later from the burnings. He left behind his wife and a 4 year old daughter. That has been an important lesson for me, and should be for everyone. My media is made of lead balls, 1'' in diameter. My BP always contains 4% dextrin for binding. Some is used for lift, some for rockets, some for fuse, etc etc. After milling i just wet it slightly, just enough to activate the dextrin, and push it trough a course sieve by hand. This is dried (within one day at room temperature) and used right away as lift charge. Pressing and corning is done by many, but i don't see the need for that. For example, when i test 1'' comets from a stargun i just dump in some lift charge, dump the comet on top and light it. The lift charge is powerful enough to shoot the comet sky high. No need to use paper wadding or cardboard on top. For me, that is an indication the lift is good enough.

 

Thanks Spitfire!

 

for the electrostatic problem i've solved grounding all the machine. I mean that rods, bearings and other moving parts are all connected to the GROUND wire.

in the first tests of the machine, when nothing was grounded, i felt near the jar the presence of a force (electrostatic for the point). after grounding the bearing (and so the rods), that effect disappeared.

 

My mill contain ALumina HD balls and the jar is a protein container winded many and many times with American Tape. Rods are steel with gum tube and several winds of american tape.

 

Do you think this could be enough to avoid risks in dry days?

I really wouldn't wet the BP!

 

what do you think the problem could be in the accident of your friend?

The metallic screen?

[Arthur]

In the old days powder was milled by water powered edge mills using big stone wheels, the powder was kept wet with river water and the waterwheels obviously created some local spray but they still had some big bangs at times.

 

In a small mill my preference is to dry the ingredients before weighing so that you get the correct mix. Even if you warm the ingredients separately to 10C over ambient they will still take time to dry.

 

At all times when doing pyro sensibly selected PPE will help to reduce the consequences of a system malfunction.

-Long sleeves, shirt done up to the neck, facemask gloves and long thick trousers. Realistically simply cover ALL skin with something that will take the hit. I spent the money and bought nomex jeans and nomex shirt, cover that with a boiler suit a kart racing flash hood and some gloves will help. You can wash sweat off but not burns, plus burns always attract the wrong attention.

[guntoteninfadel]

PPE

 

 

Whats PPE?

[spitfire]

 

what do you think the problem could be in the accident of your friend?

The metallic screen?

 

As we only got information from what the rescue team told the family, it must have been something like static electricity building up during his milling process, maybe his own clothes... at least something sparked on the moment he emptied his jar. Not to speak bad over him, but he was known as a large scale pyro and not too familiar with safety precautions. The mix of those two facts are deadly: not if, but when an accident will happen is the question in this case. This accident became the red line in my years of pyro, never EVER forget you deal with energetic materials that won't give you a warning. They just blow up in your face. With everything you do, even the smallest ''evening quicky'' remember the true nature of this stuff, Murphy's law will apply sooner or later. All you can do is THINK before you act.

 

just my 2 cents.

[Mortartube]

Whats PPE?

 

Personal Protection Equipment. Masks, gloves, goggles etc

[Arthur]

Whats PPE?

 

 

Personal protective equipment! - ANYTHING that protects your person. Shorts and T shirt is really BAD, full fire turnout gear may be OTT. Protect your face, head, body, arms, legs and feet, they are yours and your only ones, and you will need them later! Plus BURNS HURT. Plus arriving at hospital with burns attracts the wrong attention and may get the law involved - which most of us don't want!

[guntoteninfadel]

LOL, I know this is not funny but I work in the ER. You show up with burns like that and you will be yelling at the top of your lungs that you do pyro because the assumption will be METH LAB. Pretty sure you can just show your teeth and they will believe you. Yes burns are terrible things. When fire gets to your lungs your are pretty much SOL. I have never had a problem with static but I have not been doing this that long. I dont like making huge batches of energetic comps but a kilo of bp going off in your face still would not be pretty. I will have to work on a grounding plan. I do wear long sleeves and pants with a respirator (hate breathing that crap) and eye shield.

[Mumbles]

To a certain extent water content in the BP makes it more prone to static. I really should find my reference for that. The old wheel mills used water to dampen the mix because it was dusty. If you didn't keep it damp, you'd have BP dust floating everywhere, which is a huge hazard in itself. A ball mill is an enclosed container, so it isn't necessary to dampen the ingredients. I've done it before, but didn't see a lot of advantage to it. It's easy to over do it, and just end up caking the BP possibly even before the comp is fully milled.

 

It's common sense and good practice to only work with powdery or static sensitive compositions when the humidity is high. Around 60% is the rule of thumb I often see cited. This means making stars, making BP, etc. Save the lower humidity days for stuff like rolling casings, spiking, pasting, filling shells, etc. Some go as far as to install humidifiers in their work spaces if they have a dedicated building.

 

I can absolutely assure you that burns suck and will attract a lot of unwanted attention. Both from the police and random people in the street asking stupid questions. I'm lucky I'm in the situation that I am, otherwise I would have gotten in a whole lot of trouble after my accident.

[dagabu]

We are running 28% humidity right now, great weather for pasting in shells, horrible weather for ballmilling anything!

 

-dag