Ball Milling FAQ

[Arthur]

Pellet sulphur takes a while to break down but you can put it all in together or break the pellets down first.

[dagabu]

Pellet sulphur takes a while to break down but you can put it all in together or break the pellets down first.

 

I saw specks of yellow after milling for several hours, I like to mill it down and screen it first.

[MrKC]

The clay has already been dissolved, so it's just pure sulfur. I'd just assume that if you were going to mill everything together, you would mill it for longer to make sure that everything was milled fine and there were no yellow sulfur or KNO3 specks.

[angelluis]

Very useful info ,I was going to by a ball mill but after seeing this i realized i could get it like $15 cheaper, and the store H.F.T is a 30 minute ride for me thank you so very much .pyro at heart

[TheSidewinder]

When someone gets banned, ALL their posts get deleted. One-click action, easy for us to do.

 

Your COMMENTS, however, have to be manually cleaned up one by one.

 

In the future, just use the Report function. Don't add anything to it, please.

 

Thank you.

[Dennisdenny]

Hey,

 

i saw someone on YouTube ( don't know the link) using just a fan whit in the middle the can attached. Does somebody know if this method works? For me it seems a very useful solution.

 

Found the link Video link

 

btw, sorry for my poor english.

Edited November 12, 2010 by Dennisdenny

[FrankRizzo]

Hey,

 

i saw someone on YouTube ( don't know the link) using just a fan whit in the middle the can attached. Does somebody know if this method works? For me it seems a very useful solution.

 

Found the link Video link

 

btw, sorry for my poor english.

 

That is a poor idea. Fan motors are not rated for the load. If the container opens prematurely, the contents also spill all over the control buttons.

[Col]

I use the guts of a old lexmark printer to mill small 100g batches, the whole drive section comes out in one piece. Its surprisingly powerful as both shafts are driven via nylon gears, i use a 500ml container (3" od x 6" long) half filled with 150 x 1/2" lead balls. Feeding the motor with 12v dc equates to around 95rpm on the container, it churns out a batch of fast bp in 3 hours.

http://i770.photobucket.com/albums/xx341/colinspyro/smallbatchmill.jpg

 

For big batches i use this one

http://i770.photobucket.com/albums/xx341/colinspyro/075hpballmill.jpg

Edited November 13, 2010 by Col

[Nessalco]

I've looked over this thread and done a bunch of searching on Google. Amazing how much info is out there.

 

I'm looking to build a mill to work with ~1 pound of composition (BP) at a time. The physical structure of the mill itself is straightforward, and calculating the reduction ratios is simple. I'll be building the mill to be used outdoors, with weatherproofing and adequate ventilation and safety controls.

 

What I didn't find much about was about the jars. Am I right in thinking the moment with the highest risk is when you open the jar after milling? I'm thinking in terms of the friction generated by opening the jar - whether it's threads or a rubber friction-fit cover as on my little 3# mill. I can see a couple of ways to reduce that risk in how the jar is sealed, but I haven't found quite what I envision - so I plan to try to make my own jars.

 

I'm assuming it's unwise to use PVC or ABS plastics for the jar, because of shrapnel risk if the mill should explode. Metals, in addition to spark risk and cost, would seem to be too likely to contain a blast to the point of catastrophic failure. I don't know that most composite materials would have the durability over the long run - though I have lots of kevlar cloth and laminating epoxy lying around. Carbon fiber might have the durability, but I'd worry about CF's conductivity.

 

Suggestions about materials? Or jars? Am I worrying about nothing?

 

 

Thanks!!

 

Kevin

[Updup]

I've looked over this thread and done a bunch of searching on Google. Amazing how much info is out there.

 

I'm looking to build a mill to work with ~1 pound of composition (BP) at a time. The physical structure of the mill itself is straightforward, and calculating the reduction ratios is simple. I'll be building the mill to be used outdoors, with weatherproofing and adequate ventilation and safety controls.

 

What I didn't find much about was about the jars. Am I right in thinking the moment with the highest risk is when you open the jar after milling? I'm thinking in terms of the friction generated by opening the jar - whether it's threads or a rubber friction-fit cover as on my little 3# mill. I can see a couple of ways to reduce that risk in how the jar is sealed, but I haven't found quite what I envision - so I plan to try to make my own jars.

 

I'm assuming it's unwise to use PVC or ABS plastics for the jar, because of shrapnel risk if the mill should explode. Metals, in addition to spark risk and cost, would seem to be too likely to contain a blast to the point of catastrophic failure. I don't know that most composite materials would have the durability over the long run - though I have lots of kevlar cloth and laminating epoxy lying around. Carbon fiber might have the durability, but I'd worry about CF's conductivity.

 

Suggestions about materials? Or jars? Am I worrying about nothing?

 

 

Thanks!!

 

Kevin

 

HDPE jars will proove durable and if an explosion should occur, you won't have shrapnel. I'm not sure why you would make your own jars, run a google search on HDPE jars, tons of stuff pops up and it would be worth getting a few if you going to make an order, for milling diffrent chemicals.

 

If you stick to the rules of safe milling, you won't have to worry about opening the jar at, be it a screw top or somthing else, since black powder (And Other comps with the same chemicals) is not friction or shock sensitive, hence why we think its safe to mill it. If your milling any other chemical it should be done alone, with media specialy perposed for that chemical or chemical group (Like oxidizers, fuels ect.). I know when milling metals like Al or Mgal you need to open the jar every half hour or so, not sure why, but otherwise I think it'll ignite or somthing like that.

 

Good luck!

[Col]

I use 3.6L and 6.3L HDPE jars, leakproof and sturdy enough to cope with 25lbs+ of lead. They cost more than pvc but imho they`re worth paying the extra.

[dagabu]

I'm assuming it's unwise to use PVC or ABS plastics for the jar, because of shrapnel risk if the mill should explode.

Thanks!!

Kevin

 

As with any explosive material, you need to provide distances from flammable items for any jar no matter what it is made from. I have sold well over 150-6" PVC jars over the past year and have yet to hear any negative remarks (except one that was not pressure tested and leaked) about them, in fact, all feedback has been extremely positive.

 

If I could make the jars from HDPE, I would but there are no glues for HDPE available and the heat forming equipment is just to darn expensive.

 

It all comes down to safety and efficiency, it you use a rubber jar and it takes 24 hours to mill good BP vs 4 hours in a PVC jar that will make four times as much in one batch, you actually have less exposure to danger with the PVC jar over time.

[Nessalco]

Great, and thanks. I have tons of PVC kicking around in a variety of sizes.

 

Kevin

[dagabu]

Great, and thanks. I have tons of PVC kicking around in a variety of sizes.

 

Kevin

 

If you have access to a Menards hardware store, they have the ends you need for the jars.

[SolarSeeker]

The starter post says that using a blender is a bad idea when making BP. I've previously read that rocket candy and other nitrate/sugar combination's can be

milled in the blender if the ingredients are milled individually then combined. While I'm not an expert on the subject it should be possible to use the same concept

to reduce the dangers of using a blender to process materials. There are a few extra precautions such as avoiding potentially explosive oxidizers such as ammonium nitrate and keeping the blender far away from flammable dust which could be ignited by the motor. That said I'll leave it to more experienced members to gauge the potential dangers involved before I add an electric blender,coffee grinder,or food processor to my set up.

[NightHawkInLight]

The starter post says that using a blender is a bad idea when making BP. I've previously read that rocket candy and other nitrate/sugar combination's can be

milled in the blender if the ingredients are milled individually then combined. While I'm not an expert on the subject it should be possible to use the same concept

to reduce the dangers of using a blender to process materials. There are a few extra precautions such as avoiding potentially explosive oxidizers such as ammonium nitrate and keeping the blender far away from flammable dust which could be ignited by the motor. That said I'll leave it to more experienced members to gauge the potential dangers involved before I add an electric blender,coffee grinder,or food processor to my set up.

Yes, it is *safe* to mill most chemicals one at a time in a blender or coffee mill. Simply mixing together finely milled potassium nitrate, charcoal and sulfur will not result in quality black powder however. A ball mill is required for that.

 

*Charcoal and other such flammable chemicals have been known to ignite in blenders and coffee mills. I only ever know of a significant explosion occurring in one case of magnalium going through a coffee mill, whereas charcoal ignitions have all been mostly harmless, but still very capable of igniting nearby compositions. If you mill charcoal or other flammable substances in a blender or coffee mill be sure it is outdoors and far away from other firework materials.

[SolarSeeker]

Well that means only one thing. (I need to replace my broken rock tumbler)

[alexthegreat00]

Two questions:

First, I have a corded (correct term?) drill with variable speeds so could I simply attach it to a 5 gallon bucket with a lid, build a little base and have it go for 10 or 12 hours? I do not see a problem with that, but there very well may be.

Second, it was mentioned above, that the RPMs had to be with in a certain range for the mill to be effective. I might have missed it, but what is that range about? Should I have 30 RPMs or 120 or are those both way off?

Thanks in advance.

[TheSidewinder]

The duty cycle for electric drills is nowhere near 100% over an extended period of time. I suspect it would be a very short short-lived drill, but you can give it a shot. Monitor its temp carefully to see if it's getting too hot.

[Nessalco]

I got my ball mill up and running, and have been able to produce some decent, consistent BP. One thing I've noticed I'm wondering about.

 

The jars I built are 4" diameter x 7" long, made of PVC fittings, and roll at about 85 RPM. I included lift bars in the jars, and use 1/2" diameter brass rod for media, cut into pieces ranging from 7/16" to 3/4" long. Starting from KNO3 prills and granular charcoal it will completely mill a batch of BP in less than 4 hours.

 

What I've noticed is 'fluffling' of the powder as it mills. When I start a 500g batch it fills right around 1/3 of the jar (with the media included) but at the end of the run the jar is at least 3/4 full. I realize the prills and charcoal are going to take up more space as they are pulverized, but this seems like a lot. Makes it very easy to tell when the milling is complete - the powder reaches a maximum volume, and further milling doesn't change that, nor improve the burn rate..

 

I've also noticed that the sound of the media moving about changes as the run finishes. Hard to describe, but at the beginning of the run there is clearly stuff moving around with the media, at the end all you can hear is the media hitting the jar - seems much louder than at the beginning.

 

Thanks to everyone who's contributed to this thread - makes it pretty easy to get a good product in a relatively short period of time.

 

Kevin O.

[Mumbles]

I've always had the complete opposite phenomena in that BP compresses and becomes denser when millling. What kind of charcoal are you using? Have you ever tried milling longer with less material? It could be that the powder expands as everything gets broken up, and then may further compress but the volume is too big to allow proper milling and things stick. If all you hear is media hitting the jar, that is a pretty good sign things are caked inside. Even if the stuff pours out, the material is probably on one or both ends with free media in the center. It can cake without becoming and impossibly hard mass.

[dagabu]

White Pine charcoal "fluffs" on me too, regular hard wood charcoal doesn't. Strange...

[Peret]

With my mill - Harbor Freight rubber cylinder - to start with it's half full of media and the powder is down in the spaces, so what you see is lead balls. After a couple of hours, when I open the jar it's nearly full and the powder is a couple of inches over the media. I notice this both with Custom Charcoal willow and commercial air-float. I've never known it cake up, except that there's sometimes a few patches stuck to the drum that I have to get out with a brush.

[Nessalco]

I use Custom Charcoal willow. I get no evidence of caking in the bottle. Everything seems to flow nicely.

 

I ran a batch an extra six hours just to see if there was a change in the effect. Nope. It seems to hit a maximum volume and stays there.

 

The resulting powder is excellent - I've lofted a few small shells with it, and it's clean and fast.

 

Kevin

[moondogman]

Motor speed controller

 

http://cgi.ebay.com/Router-Speed-Control-Variable-Speed-Controller-NEW-/270551788275?pt=Routers_Bits&hash=item3efe24aaf3

 

Would this work for adjusting the speed on a ball mill?? Decent price!

 

Steve