Ball Milling FAQ

[Mumbles]

I'd be wary of placing charcoal in an oven. Not necessarily for safety reasons, but more for odor reasons. I'd seal the charcoal up in a container with a desiccant or something instead. Generally, it's best to store freshly cooked charcoal in a sealed container from the get go. When I dried my nitrate out, it didn't lose a lot of mass, but it transformed noticeably from somewhat translucent to opaque. I could definitely tell the difference when it was powdered as well. A little bit sure makes a difference. This material was stored basically exposed to the elements for 5+ years before I ever had much of a problem.

 

I've never really understood this. Commercial airfloat doesn't exhibit the same properties. I've stored bags outside for years and never had a problem. It seems to be select for good hot charcoal, or home cooked stuff at least. There has to be a difference in the wood sources or maybe cooking times or temperatures.

[captainG]

Well..no odor from the charcoal in the oven put them both in for about an hour on 250...worked like a charm no clumping thanks guys

[aussiekid]

What sort of reasonable media can be found for cheap in Australia? I just don't really want to use sinkers or something. Cheers

[Arthur]

You can make lead balls, you could buy lead balls but shipping would be a killer. You could likely buy ceramic (alumina or Zirconia) balls.

[aussiekid]

So casting I presume? Or am I going to have to find a shot tower? Lol

 

And surely ceramic media can produce sparks.

[PyroUK]

great post as i just recived my ball mill a few days ago, thanks!

[taiwanluthiers]

For casting your own, it doesn't have to be a ball. You can make molds out of wood by drilling holes in them, and the pouring lead into those holes. This will make cylindrical media which works just as well.

 

If you can find wheel weights for free, it will provide plenty of free lead but I hear lots of places will no longer give those away.

[MrB]

If you can find wheel weights for free, it will provide plenty of free lead but I hear lots of places will no longer give those away.

Most of the world no longer used lead media, so they simply don't have anything to give away. I think thats more of a cause, then not wanting to give it away.

Im sort of lucky in that department, since "we" still use lead on the trucks, and i simply collect the scrapped lead weights every now and then.

B!

[OldMarine]

Since I'm a plumber I have a nearly endless supply of lead I can use to cast .50 caliber media. Has anyone tried adding an antimony alloy themselves such as this: http://www.rotometals.com/mobile/Product.aspx?ProductCode=SuperhardAlloy

 

I'm not sure what proportion should be used but the price is reasonable.

[rogeryermaw]

iirc the standard is 12% antimony.

[OldMarine]

iirc the standard is 12% antimony.

I think I'll give it a try because shipping lead is pricey. My mold only makes 6 balls at a time do I guess I'll set aside a weekend just for pouring.

[Mumbles]

12% being a standard is mostly because Linotype is readily available, and quite hard. To spread the supply, I know a lot of people who use 1:1 soft lead:linotype.

 

http://pnjresources.com/Hardness%20of%20Lead%20Alloys.htm

 

You have the right idea though OldMarine. Adding a high antimony lead alloy is the easiest way to create hard lead alloys for milling. The 30% antimony is probably the most cost effective for you, unless you come across a good deal on Lyman or Linotype lead. Linotype is what they make/made the characters for printing presses out of. Trying to add elemental antimony versus pre-alloyed material is more of a pain than it's worth.

[OldMarine]

12% being a standard is mostly because Linotype is readily available, and quite hard. To spread the supply, I know a lot of people who use 1:1 soft lead:linotype.

 

http://pnjresources.com/Hardness%20of%20Lead%20Alloys.htm

 

You have the right idea though OldMarine. Adding a high antimony lead alloy is the easiest way to create hard lead alloys for milling. The 30% antimony is probably the most cost effective for you, unless you come across a good deal on Lyman or Linotype lead. Linotype is what they make/made the characters for printing presses out of. Trying to add elemental antimony versus pre-alloyed material is more of a pain than it's worth.

 

Hmm...my son works for a printing plant. It's been in business since the 20's so I'll bet a dollar to a donut they still have type lying around somewhere. Thanks for the tip!

[rogeryermaw]

If anyone is really interested in attempting to alloy these metals, this particular thread is a fun read. From castboolits:

 

http://castboolits.gunloads.com/showthread.php?63657-Alloying-Antimony-Tin-Lead

Edited September 29, 2015 by rogeryermaw

[otto]

I cast a pile of media from foundry type, a much harder alloy with an antimony content around 23%. Monotype is also harder than lino coming in at 19% antimony content. Both cast well but are sometimes work to get out of the molds due to their lack of shrinkage on cooling. A plus is they are really hard without quenching and the sprue snaps off pretty cleanly right out of the mold. I could probably quench and get them that much harder but I was anxious to make them and just skipped that step. Maybe next time around.....

 

Part of the trade-off in using a harder alloy is the density decreases so it weighs less. Even though the weight of the media does some of the work I suspect, since zirconia is such an effective media, that hardness is an equally (or even more) important attribute.

[OldMarine]

Well,I started pouring my alloyed lead but decided it would take me a month of Sundays to complete so I broke down and ordered some ready mades on eBay.

http://www.ebay.com/itm/381428893074

 

Ordered 2 and shipping was only $5.50

for the lot. I'll continue to pour my own as the mood strikes.

[OldMarine]

Nowhere better to ask this: I've got the double barrel Harbor Freight tumbler with plenty of lead media.

The question is.. can I build a single jar to use the space that the 2 rubber cans would have occupied?

[Arthur]

Some tumblers will not turn two drums full of lead media and ingredients. It's difficult or expensive for individuals to mould rubber drums -If you are used to rubber drums then you may dislike plastic drums which tend to be noisier.

[OldMarine]

After a little investigation I'd say you're correct. The motor on the double drum tumbler is the same as the single drum model. It will do well to turn even a single full load. I'll use it until I can build a larger one.

[Arthur]

My findings are that a mill intended as a rock tumbler doesn't run well when filled with lead media, but will work well when filled with ceramic media and ingredients.

[Ubehage]

I have learned a trick, that before you start your ballmill, you rotate the drum the "opposite direction" half a revolution..

 

I learned it from this video (He gives the advice at 9:58)

[Col]

Personally i`d fit a stronger motor. If the power drops out for a few seconds without you realising it, the motor may catch light trying to restart the barrel. Another option is to fit a safety switch designed for power tools on the mills supply line to prevent it from automatically restarting after power is restored.

[calebkessinger]

Yep.. I ran an under powered mill for years. A power failure at night killed it..

 

Now I just use one of these bad boys.. Had to buy one from Myself!!!

 

Edited October 19, 2015 by calebkessinger

[Col]

I use a 3/4hp motor, with the reduction it has enough torque to tear your arm off

[starxplor]

Yep.. I ran an under powered mill for years. A power failure at night killed it..

 

Now I just use one of these bad boys.. Had to buy one from Myself!!!

 

 

I wish I could justify the price for one of these, they look amazing on your site.