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How many hours do you ballmill your BP?


Ubehage

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A LOT of folks do a Kilo charge of powder in those jars. It is a little overcharged by the book but seems to work none the less.

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A LOT of folks do a Kilo charge of powder in those jars. It is a little overcharged by the book but seems to work none the less.

It does work, yes :)

But, 95% of the time, your BP will not be as good as it would've been with the right milling.

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Does anyone know the exact volume of the Chicago Electric 3 lb Ball Mill Jars? Mine actually is a 6 lb mill with 2 separate but identical 3 lb jars. I'm trying to calculate the volume of one so I can get the total volume I can run and make maximum power BP . My BP I found isn't at the quality it needs to be for lift.

 

PS I went and got another 100 .495 (50 cal) round balls for each jar so now I have 200 lead balls in each jar and they sit exactly halfway up the jar.

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It does work, yes :)

But, 95% of the time, your BP will not be as good as it would've been with the right milling.

I agree completely, sort of.... ;)

 

I would say that you would not get powder as good as you would if milled for the same amount of time with an overcharged mill.

 

I routinely overcharge my mill. I use brass rod stock for media, and mill the charcoal first, for one hour. I then add the additional balance and mill for three hours.

 

My jars are 4" ID x 7" long - wrong proportion. They turn at 86 RPM, which is the 'right' speed. They are about 1/3 full of media when I start (8 pounds) about 1/2 full when the KNO3 and sulfur are added, and full to the brim after milling. If I continue to mill the powder, it starts to clump after about 5 hours. The batch is 500g.

 

I've charged the mill "correctly" and it does the same thing, just faster. The powder is hot in 2.5 hrs, and starts to clump after 3 hours. There is no difference I can tell between the powders in everyday use.

 

I make twice as much in 5/3 the time, with less effort invested in measuring and processing. <shrug> No, it's not optimal, but it is effective, consistent, and convenient.

 

Kevin

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MY BP has been going for 20 hours and it's clumped into a uniform solid hard rock 3 times now, and all the media sitting on top of the rock of BP. Is that what you guys mean by "clumping"? I have sifted and broken the clumping 3 times now and added it back in to continue milling.

 

After the 4th time I took out about 3 Oz out of each jar, broken the rock up, screen and sifted it back into the jar and reserved the remaining 6 oz for the next run. Now there is about 5-6 Oz in each jar plus 200 50 cal (.495) lead round ball shot.

 

Does the clumping indicate that it's "hot" and maxed?

Edited by Nickmaslo
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when mine reaches that clumping stage i find its as hot as its gonna get but its also very dry were i live so i guess your best bet would be to test it and see how it performs

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I think there are two reasons for clumping. First is moisture in the chems. Second is heat generated by the media impacting itself melting the sulfur and causing the powder to clump. I know that after 3 hours of milling, my media and powder are distinctly warm.

 

Kevin

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I think there are two reasons for clumping. First is moisture in the chems. Second is heat generated by the media impacting itself melting the sulfur and causing the powder to clump. I know that after 3 hours of milling, my media and powder are distinctly warm.

 

Kevin

 

+1 about possible excessive moisture in the chems - likely culprit is the KNO3 or even the Charcoal. It may be worth drying them out first and keeping them stored in a container with some desiccant. It shouldn't clump as much as described.

 

I haven't heard of media impact making the sulfur melt slightly and cause clumping. Interesting, I guess that makes some sense when I think about it.

 

Cheers.

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sulfer melts at 203 degress +/- , my mill gets warm but not even close to that.

 

memo

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Yep, sorry. Not nearly that warm. :blush:

 

Kevin

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sulfer melts at 203 degress +/- , my mill gets warm but not even close to that.

 

memo

203 (Celcius) is close to the critical temperature for BP.. So I hope not :D

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According to google. Sulfur melts at 240 degrees Fahrenheit. My mill and media are certainly warm also as Im emptying, but definitely not hot enough to boil water. I do not believe sulfur is melting here.

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According to google. Sulfur melts at 240 degrees Fahrenheit. My mill and media are certainly warm also as Im emptying, but definitely not hot enough to boil water. I do not believe sulfur is melting here.

i went to google and it has several melting points 203 f to 240 f +/- , my mill is still not that hot.

 

memo

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Overall, no one's mill should be that hot. If it's melting, it's from localized heat generated from impact. I'm not convinced this is happening though. Moisture from the nitrate, charcoal, or even the mill jar could all be culprits.

 

For me, it was mostly the charcoal. My nitrate was prilled and relatively coarse, so I milled most compositions (the safe parts at least) containing it for a little bit. When making polverone using commercial airfloat, it came out a free flowing powder. When using willow for hot BP, it clumped almost every time. There was a difference in milling time too. Lots of factors, just passing on my experience.

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If the ingredients are damp then the mix will clump before it has properly milled, If the ingredients are dry then clumping is much less likely and happens when milling is complete. If there is dextrin in the mix then it's important to mill it very dry or the dex will glue it all together too soon.

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Tyrone, I have since done some more reading on the subject. I conducted my own experiment over the last 2 days and here is what I determined: I can make good fast bp with my current setup, but I have noticed some variation in power from time to time. Also, I threw some of my bp meal back into the ball mill (500g) and milled it for an additional 4 hours. Well, when I did a burn test, it was noticeably faster. So..... long story short, I made a list of parts to build Ned's double barrel ball mill setup. I like the idea of charging a mill jar as efficiently as you can, and being able to turn it at about 65 rpm's without worrying about the motor overheating. Plus a built-in timer, circuit breaker, it's a no brainer. I am gonna go for it. :)

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Brad, as much as we would like to load the mill up and crank out kilos of BP at a time, we will find that charging the mill efficiently is the much better option in the long haul. Are you also on FW? Ned's setup will make 48oz of BP in 90 minutes. Its a pretty slick deal. You will be very happy with your results. I just got my new mill running and from what I have found, the larger diameter of the mill, the more efficient as well. I believe it has to do with the media having more distance to fall per rotation. My mill is 10" inside and cranks out 4.2 lbs in just over an hour. Only bad thing is it takes 87lbs of lead to fill.. :blush:

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Does anyone know the exact volume of the Chicago Electric 3 lb Ball Mill Jars? Mine actually is a 6 lb mill with 2 separate but identical 3 lb jars. I'm trying to calculate the volume of one so I can get the total volume I can run and make maximum power BP . My BP I found isn't at the quality it needs to be for lift.

PS I went and got another 100 .495 (50 cal) round balls for each jar so now I have 200 lead balls in each jar and they sit exactly halfway up the jar.

I filled my jars with water for volume calc's.

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Tyrone, I am on FW and I have printed out the plans for Ned's double barrel mill. I am getting ready to build it. I did some more speed tests this evening, after milling a batch in my mill with the jar 1/2 full and only 500g of chems, I am convinced that proper charging is key. I agree with you that optimum efficiency is key, as opposed to brute volume. With the new mill setup, I can get er cranking at 60+ rpms!!

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Atta boy! You will love that mill setup
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I believe I will! The Thumler's mill is nice, but even the high speed model is nothing compared to a solid 60-65 rpm's. Man that is flat out haulin ass! I think my mills turn about half that speed (30-35 rpms). Plus, I like the idea of the shafts running on pillow block bearings instead of the little plastic bushings on the Thumler's setup.

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In my experience (which isn't all that much as of yet), I ball mill my BP for a bare minimum of 2.5 hours. All the ingredients are ground and screened separately. I then usually ball mill my charcoal and sulfur for 1.5-2 hours first, using .500 steel balls. I then mix everything with a mortar and pestle for 5-10 minutes before I load it into the ball mill (.500 lead balls at this point.) All this preliminary work seems to reduce the needed final ball milling time. I have had great results doing this. BTW my ball mill is home made: wooden blocks with casters mounted on a board. I simply use rubber bands for a belt. I also use a large glass jar. I know some would think this is dangerous, but it is operated remotely and contained, so I'm not worried about flying glass in the case of an accidental ignition. I feel glass is considerably harder than pvc and this makes the milling process more efficient.

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Get rid of the glass. We had a member here lose a finger due to milling with glass when they opened the jar!!!! Not from the milling operation. In no way can I let that slide.

 

No need to screen and grind by hand. Even a poorly setup mill is far faster than hand grinding.

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In my experience (which isn't all that much as of yet), I ball mill my BP for a bare minimum of 2.5 hours. All the ingredients are ground and screened separately. I then usually ball mill my charcoal and sulfur for 1.5-2 hours first, using .500 steel balls. I then mix everything with a mortar and pestle for 5-10 minutes before I load it into the ball mill (.500 lead balls at this point.) All this preliminary work seems to reduce the needed final ball milling time. I have had great results doing this. BTW my ball mill is home made: wooden blocks with casters mounted on a board. I simply use rubber bands for a belt. I also use a large glass jar. I know some would think this is dangerous, but it is operated remotely and contained, so I'm not worried about flying glass in the case of an accidental ignition. I feel glass is considerably harder than pvc and this makes the milling process more efficient.

Glass can accumulate extremely small static charges, and release it suddenly when there's enough to make a spark.

And, as tyroneezekiel said, there was an accident with a guy using glass.

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