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Ball Milling FAQ


Mumbles

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To answer a few questions:

 

-The container is PE plastic.

-Brass is always polished dry.

-The bowl is designed to slowly turn over the media.

-I have a couple of blade grinders and they work well, but still dont produce a fully powdered, talc like product. This vibratory does it completely and rather quickly.

-I am a retired mechanical engineer who focused on mechanic design, automation and robotics. In my career I actually did some designing of monstrous vibratory polishers that were up to 20 feet tall snd 50 feet long, but with the right media ((usually ceramic) were used to polish fine China.

-I am a totally competent fabricator and builder, and have half the stuff to build a rotary tumbler in my shop. The only reason I tried this is, Im limited due to an elbow surgery, and I already had the vibratory polisher.

-I have used hardwood lump charcoal and homemade Easter red cedar in it. I do a pre-mill in a food processor.

 

One observationI have used half inch balls in it to this point. It seems that with the vibratory action, smaller media may be more effective.

 

And Im definitely not trying this with any mixed ingredients as long as all I have are glass marbles.

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Just wondering if anyone else has tried this; I dont have a tumbler ball mill, but I do have a vibratory brass polisher for bullet reloading. For an experiment, I dumped the media, poured in some marbles (I know its a big no no but this was just a test on charcoal) added some ground charcoal and turned it on for any hour. It was quite noisy, but it produced perfect air float charcoal powder.

Anyone else experiment with a vibratory polisher?

Just wondering if anyone else has tried this; I dont have a tumbler ball mill, but I do have a vibratory brass polisher for bullet reloading. For an experiment, I dumped the media, poured in some marbles (I know its a big no no but this was just a test on charcoal) added some ground charcoal and turned it on for any hour. It was quite noisy, but it produced perfect air float charcoal powder.

Anyone else experiment with a vibratory polisher?

 

No, I haven't yet tried using one but it is definitely planned for a near future trial.

 

After watching this video where Black Powder was made with such a Tumbler, the curiosity took hold.

 

Several videos were found on YouTube which demonstrate how such Tumblers work, and even how to make one.

 

What is fascinating about the Vibratory Tumbler is how the material and the media circulate while it is in operation.

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No, I haven't yet tried using one but it is definitely planned for a near future trial.

 

After watching this video where Black Powder was made with such a Tumbler, the curiosity took hold.

 

Several videos were found on YouTube which demonstrate how such Tumblers work, and even how to make one.

 

What is fascinating about the Vibratory Tumbler is how the material and the media circulate while it is in operation.

Sounds great in principle, but unsure about the 5-pound capacity HF model you linked to: 17% 1-star ratings.Yipes.

 

They also sell an 18-pound capacity unit that only has 7% 1-star ratings, but that's more than twice the price ($USD145).

 

Motors burned out, threads stripping, and impossible to get replacement parts.

 

Might be worthwhile to get a Thumbler or other known brand...

 

Would love to see a side-by-side comparison with a similar capacity ball mill using the same media!

Edited by SharkWhisperer
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slohand637, I'm a fan of single component milling, and I find that the fineness of the grind on the charcoal is a huge factor in performance. Some quick baseball tests with screen-mixed, granulated powder would give a good idea of how well the tumbler works to make fine powder. In my ball mill, I use very small media for the charcoal, 5/16" diameter.

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From SharkWhisperer:


Motors burned out, threads stripping, and impossible to get replacement parts.

 

There are definitely some tricks to using the Vibratory Tumbler which will prevent those common problems and prolong its useful lifetime.

 

It is important to load it properly to avoid excessive vibration and to secure the top lid firmly to prevent it vibrating loose while in operation.

 

Using the Vibratory Tumbler to pulverize chemicals will be far less abrasive to the plastic Barrel than when it is used to round and polish rocks or other sharp objects.

 

While not specifically applicable to the Harbor Freight model, the principles involved are common tips:

 

8 Ways to Extend the Life of Your Vibratory Barrel

 

 


Would love to see a side-by-side comparison with a similar capacity ball mill using the same media!

 

Yes! I would like to see something like that too. Hopefully, someone with the requisite skills and facilities will make the comparison on video.

 

Some replacement parts are available.

Edited by SeaMonkey
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  • 2 weeks later...

Ok, just getting started and have some housekeeping questions. I have been reading up for several months and have made three batches of 60 grams each in the last few days.

 

What do I do with the "other" jar that came with my H-F 6# 2 jar mill? I have been using one jar to grind my charcoal, a paint brush with "fuel" written on the handle in sharpie to brush out the jar when switching to BP, and a grey handled paint brush to brush out the jar before going back to milling charcoal.

 

I was/am reserving the second jar to mill oxidizers, but it seems like I really have just a spare jar at this point. I am starting with KNO3 from the garden store and it seems to do fine without having been premilled.

 

How many sheds do I need to do this safely? My workbench is now top coated in charcoal dust. I am going to have to either replace the top and stop pyrotechnics or just dedicate my now filthy bench to pyrotechnics and get a new work bench for everything else. I am thinking something like a picnic shelter for the mill, one "place" to keep the oxidizer (maybe in the greenhosue with other fertilizers), a magazine for finished product, and the dirty workbench somewhere else near the press I don't have yet also away from the house.

 

FWIW I envision a future mill that can do about 20 kilos at a time so I can just make a bunch of powder and get on with it.

 

So 1 shed way away from everything else for the mill, shed #2 for oxidizers, shed #3 for the magazine (class 4 up to fifty pounds), and then #4 a workplace to make stars and comets and build rocket motors and so on, away from the house and all of the other three? So four outbuildings, each at least 100 feet away from each other. If I plan correctly I can take over the magazine shed for press and bench and star mill and so forth after I build an inground magazine.

 

Thankfully I have a few acres, but I don't want to go rent a skid steer and tear up the lawn without a clear plan.

I was in the same position with an extra jar then I discovered a defect in one of my jars and they sent me two new jars. And then I came up with this idea

 

https://youtu.be/omxfs5j0qc8

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  • 1 month later...

A thing is "safe" when the risks are acceptable to you.

 

Many of us repeatedly do risky things. The more we do them (and get away with it), the "safer" they seem. Eventually, they don't seem risky at all.

But actually, every time we do them, the risk remains the same and applies every single time we repeat the operation. Repeating the operation is actually NOT SAFER over the long run.

Think of russian roulette, but with more chambers in the revolver.

 

Professional operations plan for an accident. They do not assume that an accident is not going to happen.

 

I don't mill live compositions with SS media, because the consequences of a very unlikely accident are unacceptable to me.

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I have milled live black powder with 302 stainless steel media, and had no accident. Not saying it's safe. Of course, the mill is barricaded, and the open side of the barricade faces into a field. And it's been run at night, preferably when it's raining ;) I felt more squeamish milling with ceramic than with stainless, due to the hardness. Every minute my mill was running, I felt uncomfortable, no matter what media was in use. That's what propelled me to investigate single component milling.

 

I generally use greenhouse grade potassium nitrate. Upon screening, I have found small, hard igneous rocks in every bag. If live BP were being milled with lead, these small rocks would be very unlikely to cause an ignition. With ceramic or stainless steel, my impression is that the risk of ignition would go up substantially. I screen my potassium nitrate for every batch now, even though I mill my BP components singly these days.

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I do understand that there is absolutely no risk free safe way when processing and handling live compositions. Maybe I should have placed the question differently, from what I have learned here SS balls are not the safest, but still not overly dangerous. They seem to be ideal for charcoal - this is my primary intention, but I am also considering if I may go milling complete composition. So I am thinking how safe it would be and how could I make it safer. Smaller drum and smaller balls are not so efficient, but the collision energy is smaller so it may be safer in this way. I would use premilled ingredients fine enough to be milled easily with smaller media. Sulfurless BP shoul be also safer, sulfur lowers ignition temperature...

Because granulating is a wet process I hope to have simmilar results combining all ingredients (ballmilled separately) in this step and give it some workout to intimately mix. This step coud be relatively risk-free.

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I like to keep a low profile and hate nasty surprises, so I mill my BP with hardened lead. I find SS is ideal for everything else that is not a live mixture

I really like justvisiting's "ultramilled" dried charcoal, milled beforehand in large batches; then my BP milling time with lead media is cut down considerably and the handling properties of the C are much improved compared to AFC... as long as I don't spill it.

Consult justvisiting's baggie/boiling water method for a milling-free wet process. I think it's brilliant and it works if you're really apprehensive (always good trait in these endeavors). Cleaner, too!

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Isn't it odd that the milling stones (wheels) at Black Powder Factories World-wide have an outer milling surface that is made from some type of corrosion resistant steel?

 

Powder factories take extreme caution always to assure that no "foreign materials" make their way into the milling process.

 

But even so, explosions still occur at the factories for some mysterious reason.

 

Are there any verified incidents of Ball Milling Accidents among those who make their own powder?

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Another thing about the wheels in the wheel mills is that the weight of the wheels is supported at a fixed height, and does not bear down on the powder. The steel never contacts anything but the powder, which is milled by a pressing/smearing action. And it is milled moist.

 

There are a few verified accidents, but they didn't necessarily occur during the milling itself. Mumbles and Dagabu had accidents, and their stories are here on the forum.

 

Another guy, BurritoBandito had a mill jar pf BP blow up in his hand when he shook it. He was milling with glass marbles, a known hazard. Glass particles are used in matches to increase friction and ignitability. His accident story is on here too.

 

The only actual verified black powder ignition during milling that I know of was a guy named Gary, from Florida. He was milling BP in a tomato greenhouse with large 'Mentos'-shaped ceramic media. He was running at a fairly high speed and had large lifter bars in his jar that he referred to as "super swamper bars". The jars and mill were destroyed.

 

There was another ignition I read about, but can't verify. This guy was milling in a cement mixer with a steel chain as media. He milled in a barn with the mouth of the mixer aimed out an open barn door.

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After reading this it seems to me that milling sulfurless BP made from pure ingredients with small SS media in small jar should be relatively safe... Anyway if supermilling charcoal alone will do the job, no need to risk such a safe milling :-)

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Just Visiting,

 

Thanks for the detailed response. Very helpful.

 

I have both Thumblers Tumbler and a Harbor Freight tumbler. Got Thumblers back in '93 and have used it a lot.

 

I got some Brass Balls (1/2 inch Diameter) back then and they're still almost like new.

 

Both tumblers are "as is" in that I haven't modified them for a higher tumbling speed.

 

I always mill slowly and even though it takes more time; I don't mind the wait. Too much violent action inside the tumbler is something I want to avoid.

 

I recently obtained a Harbor Freight Vibratory Tumbler to do some test with. I believe the Vibratory Tumbling action may have some advantages.

Edited by SeaMonkey
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I recently obtained a Harbor Freight Vibratory Tumbler to do some test with. I believe the Vibratory Tumbling action may have some advantages.

I look forward to hearing your results if you decide to share.

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I look forward to hearing your results if you decide to share.

I too look forward to your results Hope it works good and you share the results.

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  • 6 months later...

Good morning. If I have the KNO3 the C the S micronized. The black powder kettle will be of good quality?

Good morning. If I have the KNO3 the C the S micronized. The black powder kettle will be of good quality?

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Good morning. If I have the KNO3 the C the S micronized. The black powder kettle will be of good quality?

Good morning. If I have the KNO3 the C the S micronized. The black powder kettle will be of good quality?

Sure. Only there’s about 3 more steps. Compacting, drying and corning come to mind. You don’t mix it with a spoon and expect good results. Milling is a start.

 

 

I’m assuming yer “foreign” ie. not from an English speaking area. Makes it hard for us Englishers to ascertain exactly what you are asking.

Edited by Richtee
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  • 1 month later...

Do ordinary steel balls contaminate charcoal during milling or is it similar to SS balls? Do they rust when left dirty with charcoal?

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Myself, I would not use steel balls for milling, they do create an increased risk of sparking. Even if you are only using them to mill charcoal, charcoal milled down to the finer consistencies can produce a fuel-air deflagration particularly while unloading.

As far as contamination, any milling media will also mill itself in the process distributing itself throughout the mixture. Steel rusts in the presence of oxygen, especially with moisture, or with a material like powdered charcoal that will hold moisture in contact with the steel.

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Every kind material will eventually wear out at certain pace, steel and SS included. For complete safe measure, I'd avoid milling any live composition in potential contamination with steel.

Every type of impurity should be taken into consideration, kind of pyro's discipline.

Ideally, you should have individual drums and media for each component you're milling. I had three drums. One for metals, one for BP and organic color compositions, one for chorates.

Edited by 50AE
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