Ball Milling FAQ

[uncrichie]

Hello everyone, my first post on APC. I've been lurking for awhile trying to absorb as much as possible. I have a few (actually many) questions regarding ball milling BP that I was unable to find archived answers for, so here goes.

 

I'm in the process of building a ball mill that will accept 4" and 6" pvc jars, at least that's the plan. However I will not be able to ballmill the final BP product at my location due to neighbors being too close. My plan was to ballmill the ingredients seperately in their own jars and then screen mix. I know this is not optimum but the best I can do under the circumstances. Now heres the questions, Is there any risk of incident with ballmilling these chemicals individually or can they be milled on my back porch? 2nd part of the question, can I safely mill the sulfur and charcoal in the same jar without incident or is there explosion potential? 3rd part of the question. Can potassium nitrate and sulfur be milled together without any explosion potential?

 

I suppose what I would be trying to do is to ballmill as many of the components intimately without the risk of explosion potential. Is this at all possible?

 

Next question, does anyone know the approximate length of a 1 gallon 6" diameter pvc balljar with 4" reducer coupling? And also the length of the 1-1/2 QT 4" jar with 2" reducer coupling? I'm trying to figure out how much roller rod to purchase.

 

Last but not least, I have a load of linotype metal that I will be melting and casting my media from. Is it ok to use straight linotype or would it have to be mixed with regular lead?

 

Oh, I almost forgot. Can I make the jars from the thinner pvc sewer pipe with matching couplings or are you guys using the schedule 40 pvc pipe and fittings (which is way expensive)?

 

Many thanks in advance. I hope this wasn't too much for my first outing. It's great being here!!!

Edited June 24, 2013 by uncrichie

[ebergstrom95]

Hey there, first post,

 

I just picked up my first ball mill (a six pound rock tumbler from HFT), and I have a few questions:

 

I would like to echo uncrichie's question about two-component milling.

Is it explosion-proof with the right combination (I was thinking charcoal/sulfur), and is it a viable way to make quality BP?

 

I was also wondering if lead, brass, or stainless steel media would still be needed for two-component milling, that is, would a powder of charcoal and sulfur be dangerous enough that it would require guaranteed sparkless media, as in the case of three-component milling? Would alumina ceramic be appropriate?

 

Also, I was wondering how much harder lead/antimony is than just lead. I'm not too keen on using lead shot for toxicological reasons. Does using hardened lead cut back on the amount of dust formed, and therefore on the risk of exposure? Am I irrational in fearing lead dust formed from regular shot? Would a regular cheap dust mask protect against dust (not just from lead, but from other particles), or is a respirator recommended?

 

Also, does anyone know of a cheap way to get brass? Online prices seem a bit higher than alternative media choices.

 

Sorry for the long winded post, any help is greatly appreciated.

[ollie1016]

Hey there, first post,

 

I just picked up my first ball mill (a six pound rock tumbler from HFT), and I have a few questions:

 

I would like to echo uncrichie's question about two-component milling.

Is it explosion-proof with the right combination (I was thinking charcoal/sulfur), and is it a viable way to make quality BP?

 

I was also wondering if lead, brass, or stainless steel media would still be needed for two-component milling, that is, would a powder of charcoal and sulfur be dangerous enough that it would require guaranteed sparkless media, as in the case of three-component milling? Would alumina ceramic be appropriate?

 

Also, I was wondering how much harder lead/antimony is than just lead. I'm not too keen on using lead shot for toxicological reasons. Does using hardened lead cut back on the amount of dust formed, and therefore on the risk of exposure? Am I irrational in fearing lead dust formed from regular shot? Would a regular cheap dust mask protect against dust (not just from lead, but from other particles), or is a respirator recommended?

 

Also, does anyone know of a cheap way to get brass? Online prices seem a bit higher than alternative media choices.

 

Sorry for the long winded post, any help is greatly appreciated.

 

Hello, and welcome to the forum!

 

There is no such thing as ' explosion proof'. People have been milling all three of the BP components together for years. You will have heard about the odd ball mill explosion. However they are rare and normally due to the jar failing and mill dust getting into the motor workings.

 

With you 6lbs HBF ball mill I recommend you weigh you jar(s) before each time you use it to make sure the net weight doesn't exceed 5lbs. I find it mills better with 5lbs than 6lbs. It will also make your belt last longer. Don't for get to lubricate the 4 roller 'bearings'.

 

1/2" lead media is perfect for the HBF ball mill jars. It's cheap and no sparking. Lead will wear over time, but it's cheap and as safe as it gets.

Lead/ antimony will wear a lot less than straight lead.

 

Dust is a quite nasty thing for pyro's, it can really ruin your day. I've found to work in a well ventilated area, maybe have an extractor fan in your work area? I have a very small draft from and extractor fan that is just strong enough to pull the dust particles away from me.

 

A standard dust mask won't do sh*t! I'd recommend a dust mask with proper air filters. I reckon they'll be around $30, and worth the investment. Also proper PPE is essential, eg face shield, a cotton labcoat( or just all cotton clothed), full length sleeves, (ear protection).

 

A guy on the forum 'Dag' just had an incident. A very respectable and professional man. It can happen to anyone of us at any time. Make sure your prepared if it happens.

 

Please feel free to PM me if you have anymore questions, and I'll do my best to answer them!

 

- Ollie

[Mia]

Wow talk about reiterating your post! Only one point lead will work harden if you run it just as a media for a few hours.

[deepdixie]

Hi guys, I'm fairly new to the pyro world. I recently purchased a ball mill/rock tumbler from a reputable pyro supply company. It is listed as having a 3 lb. capacity. If filled 1/4 - 1/2 full with lead media the jar weighs far over 3 lbs. Won't the motor burn up if carrying too heavy a load? I milled 2 ounces of black powder for 4 hours with no problems with the barrel nearly 1/2 full of media. The mill felt hot to the touch but worked fine. My guess is that these hobby pyro mills can handle far more than the capacity they are rated for. Why else would this reputable company sell a 3 lb. capacity mill when it takes over twice that weight in lead media alone in the barrel to produce the needed results? I would appreciate any feedback ya'll could give me.

[Mumbles]

Those pound ratings are actually in relation to their rock tumbling applications. It's the approximate load they will polish. As an approximation, when being used for milling BP with lead, they're going to be about double that in weight. I never burned out the motor on my 3lb model, despite regularly running double that for 7 or 8 years. You might not be so lucky to get that long out of one, but they definitely take the abuse and will pay for themselves in no time.

 

The one issue you might run into is the drive belt breaking. I don't know if it happens due to the increased load, or that they're just not great quality to begin with. I replaced mine with a heavy duty o-ring after breaking about 10 belts, and never had to worry again. I know some of the suppliers sell higher quality replacement belts.

[deepdixie]

Mumbles, Thanks for the input. Your reply was along the lines of what I had assumed the true capability of my mill would be. The mill I purchased came with several extra replacement belts. Hopefully it will last for many years milling small quantities of BP.

[Dodad]

I would like to know if anyone has used Thumblers Tumbler.

 

http://www.activepowersports.com/thumlers-140-model-b-rock-tumbler/

[Dodad]

Perhaps I need to start a new thread?

[Bobosan]

Thumblers supposedly has good product. I use the 15lb drum on my home built mill frame so don't know about Thumblers frame or motor.

 

Edited September 25, 2013 by Bobosan

[Dodad]

That's an interesting design. Can you post some pictures showing the construction?

It looks like you used something other than pillow bearings. Did you buy the drum by itself?

[Bobosan]

It's about 5 years old with 200+ hours run time. Unfortunately, no build pics were taken. It's all 3/4 birch plywood finished with 3 coats polyurethane. The secondary drive roller is adjustable for different jar/drum sizes. I didn't have a TEFC motor so isolated the motor from the mill area with this setup. There are more pics in my gallery with descriptions.

 

Bearings are cheap ones just pressed into the wood sideframe holes. Pyrocreations used to sell the drums seperately and that's where I got mine.

 

edit - just realized that the end pieces and grab handles of this mill are oak and solid pine (light yellow color) so it's not all birch.

Edited September 25, 2013 by Bobosan

[wrongway]

Awsome artical Thanks!

[rsto]

great, thanks

[urmi]

Hi,,

 

Let me know How to crush Ti sponge using ball milling. I have Stainless Steel and Tungstun carbide Jar and balls.

Which one is good for crushing Ti Sponge?

[Gordon]

Hi, first post here

 

Building a ball mill from garage scrap... hoping it doesn't cost anything.

 

I have some stainless and brass rod I can cut up for media, but it's so darn expensive. Can I use re-bar instead? Planning to use it for BP. No immediate plans for anything more exotic. thanks.

[MrB]

I have some stainless and brass rod I can cut up for media, but it's so darn expensive. Can I use re-bar instead? Planning to use it for BP.

Sure. But let me ask you this... Whats more expensive? The crew that has to wipe you of the wall after your rebar lights your jar on fire, and sends the lot through the roof, or getting some proper media?

 

I'm sorry, but... rebar? Really? Thats probably the worst thing you could come up with, as an improvised milling media. If you go with that option. Please let me know where you live, so i can avoid going there.

Hell, let me know, so i can have someone go over there and slap you silly, before the mill is built, and you become a liability to your surrounding.

 

Again, i'm sorry, but... NO. NO NO NO. None sparking media. ESPECIALLY for BP. The more exotic stuff is probably less dangerous then BP anyway... Since BP is about the only live composition you will ever mill.

B!

[Gordon]

Thank you for being polite and succinct.

 

No sparking media.

Edited August 1, 2014 by Gordon

[Bobosan]

Gordon,

 

Go with the brass for the mill. Save the stainless for rocket spindles later on.

 

Lead media is the safest media for use in BP mills.

[Mumbles]

Sorry, one of our members had an accident during ball milling a few weeks ago, so a lot of people are a little on edge. http://www.amateurpyro.com/forums/topic/9798-ball-mill-explosion/

 

As others have said, rebar is not going to be a suitable media. I know you're hoping for zero cost, but lead shot isn't all that expensive and very safe. Perhaps consider taking your savings in materials for a jar, motor, and wood/hardware, and spending a little on media. You never stated how large of a mill you're intending to make, but you can supply a mill capable of making about 200g of BP per batch with media for about $20-25 in lead.

[MrB]

Thank you for being polite and succinct.

Sorry. I'll remember to be more polite next time, when i'm saving someones life.

B!

[BurritoBandito]

I just found this thread. Gordon, please take these guys advice. I can not stress enough how important proper milling proceedures are. Things like media, jar construction, motor choice, loading/unllading method, ect. should all be taken into careful consideration. I used glass marbless for a long time without issue. Late on the fourth (technically early on the fifth) I learned the hard way that I was just playing the odds. It is crucial that you follow the rules in pyrotechnics. Failure to do so can be, and often is, catastrophic.

 

Edit: Gordon, could you please give some details about you mill plans? Specifically the motor and jar. I don't want to flame you or anything like that, but I do not want you having an accident. MrB is a bit... eccentric? but he is looking out for you. Please understand that. Mumbles has sooo much knowledge in his head that it's just ridiculous, and there are many other smart people here that know what they are talking about. They are here to help. Do not be afraid to utilize this resource, but please take the advice of the more experienced to heart, for your own safety, as well as those around you.

Edited August 3, 2014 by BurritoBandito

[oldspark]

I think informing people (about the dangers) with out talking down to them will help in them keeping an open mind.

This hobby can kill you in a heart beat so please people research research research.

Read 10 times build once or not at all, cheap does not cut it for some things period.

Edited August 4, 2014 by oldspark

[Merlin]

As far as BP milled and granulated goes whether dextrin or redgum the Grandmasters suggestion you let it dry a week is probably the most important overlooked step by newbies like me.

I am considering building a drying box. Get the chems ball milled well in the right proportion, granulated, and dried. The last I think is the most tricky. Thus a drying box.

[AldoSPyro]

Just milled some kno3, it turned grey... Is that normal? I'm using a rubber drum with lead media, will the grey color effect it's performance?