About lead ball mill media. Weight, and size?

[MrB]

Looking to get at least 2 sizes lead media. Or actually, i'm looking to get 2 casts for different size media, since i'm a cheap SOB. But... What sizes, and what amount of lead should i expect to use? (Weight)

 

Currently i got free access to disposable "milling jars" (read training supplement containers) that has been working well with my ceramic media. Contains about 3L in total.

(OD 13cm, length 15cm.) I'm looking for something slightly bigger to make this setup my "small stuff" mill, but it's not really a priority. The jars are perhaps slightly to long, has rounded edges, and the closing lid sits on a neck. Not really optimal in so many ways, but it's been free, and working.

 

So, on with the questions.

 

Can i simply take half the jars volume, (1.5L) times 0.75 (spherical media "waste") and run with 1.125L volume, times 11.34 (lead specific weight, dm3) and come up with 12.7575kg for media weight? Regardless of media size? (I think so, but... And yeah, i know it doesn't account for the antimony content which would give me a couple of "free" balls at these weights. I didn't feel like deducting x% of lead to add in the weight of antimony, so i'll live with the few extra balls. Next time people ask if i got balls, i'll just answer "yeah, got extras to")

 

For the current, fairly small size milling jars, what would be "right" for size? Pretty much got free choice of 8-28mm media, or a "multi" cast netting 12-30mm media.

 

Quenching the media, Yes, or no?

 

Aiming for a 4-6% antimony content, it's my understanding that the lead media will harden slightly over the next 30 minutes after casting, and doesn't really benefit from quenching. Quenching is apparently effective with antimony-lead alloys, but only gives the advantage of reaching the ending hardness faster. Which pretty much means i could do without the wet mess and just leave em to cool. Am i miss informed, and should really include water-quenching in my ball-making process, or can i just skip that step, make all the casts i can from what lead i got, cut of the excess from the now slightly cooled casts, and toss em back in the melt? Wet lead in to a hot melt is a mess in the making, i've tried that before. Not that fun. So if i'm quenching, then i'm making what i can with what i got, and restart another day when the casts have quenched, cooled, and dried of.

 

I think thats all i got right now. Sorry 'bout them questions.

B!

[Col]

As a rough estimate, 512 x 12mm diameter lead balls per litre volume, weight is around 6.14kg. A jar 13cm diameter x 15cm long has a volume of 2L, the easiest way to accurately measure odd shaped jars is to fill them with water. Edited January 7, 2013 by Col

[pdfbq]

I can tell you what I use.

I have 1.3 liter jars (15cm x 11cm) and use 50 ~14mm and 50 ~12mm lead balls all together 1.5kg

It makes FAST meal in 3 hours.

My experience is that for meal, when lead is used you don't need the jar half full.

 

I also have ceramic media for my other chemicals Then I have my jar half filled.

[MrB]

As a rough estimate, 512 x 12mm diameter lead balls per litre volume, weight is around 6.14kg. A jar 13cm diameter x 15cm long has a volume of 2L, the easiest way to accurately measure odd shaped jars is to fill them with water.

Oh com on. Now you've proved i can't even remember the most basic math, and your not even gloating. Yeah, i messed up the math bigtime, failed to calculate the area of the bottom correctly, and hence got a bad answer. Thanks for not gloating.

I'm not sure why we get so different numbers for the weight of a liter of media, as long as it's a uniform size it "should" waste about 25% of the space, and if thats true, a liter of lead balls should weigh in on about 8.5 kilos.

I'm guessing it's the difference of practical experience, and maths that does it? (sphere "stacking" in a container is at best 75% effective, i'm guessing random, or purposely ineffective stacking could give you a lot different results. Again, i'm glad i asked. At any rate you gave me a figure of about 54% stacking effective, and again, the same "should" hold true for any size. Thanks.

 

Am i to take it that the recommended size for this size jar is 12-14mm, and that i might want to go up some in size for larger particles, and future jars?

 

And nobody had any thoughts on the casting / quenching of media. I wonder if i have any mates that still shoot bp guns, and cast their own bullets. They should have some info on this. I'll put whatever i figure out in the end on here.

B!

Edited January 7, 2013 by MrB

[Col]

I use 12mm in 640ml and 4.37L jars it works fine in both. I dont know about anything bigger as the only other media i use is 3/8" alumina.

I cast 20kg of 12mm lead media over a couple of weekends, then reheated it job lot and quenched it as fast as possible in 200L of icy water.

[Bobosan]

I cast my 15mm (.600) media using wheel weights and linotype usually in a 75/25. The wheel weights already contain a fair amount of antimony. If using straight lead, a 50/50 mix works best. Water quench in a coffee can with a wadded rag at bottom. to prevent deformation. Cover the can with old T shirt material and affix using a large rubber band. Cut a 1-2 inch slit in the center of T shirt allows the cast lead to fall from the mold onto the T shirt and then roll down through the slit. Keeps from splashing hot lead or water on you. Using gloves and eye protection is highly recommended.

 

The quenching definitely helps with overall hardness of the lead but you have to keep the water cool and it doesn't take long to heat up a coffee can full after a 20-30 quenchings.

[MrB]

The tin from the linotype helps with the melts flowing abilities? Or your just not satisfied with the antimony content from the wheel weights? If memory serves me right, linotype is like 4% tin, 12% antimony, and the rest is lead.

Looks like i'll have to figure something out as far as quenching goes, both of you seam to suggest it's worth it. The cast i'll be using has a row of balls in it, so they don't exactly roll anywhere, but i guess i could use a barrel with a towel on the bottom, and just empty / refill it when/if the water heats up. I'll figure something out.

 

15mm media, your using this with a milling jar of what size?

 

When it comes to my repeated size issues. (Where is the girl that keeps telling you size isn't everything, or even that size doesn't matter, when you need her) Primarily i'm looking for an idea of what will be useful to me in the future, i could easily go with 12 & 20mm media, But i'd hate to have to buy a new cast if / when i get a larger mill. Right now the larger media would be used to start out the charcoal, it's a bitch with the ceramics i use now, and i figure that smaller media have an issue with the larger chunks of the fresh coal. To some extent i can use manual labor to make it smaller, but thats about it. I'd prefer to be able to make thin sticks, bake em, and after cooling just put em in the milling jar.

 

 

B!

[Bobosan]

Fluxing the molten lead with paraffin helps with flow into the mold and helps to float the impurities slag from the lead. Lead temp and mold temp are also major factors to take into consideration. The linotype increases hardness in the lead reducing amount of wear on the media. I'm using a 15lb mill jar and if I remember correctly, held about 1.25 gallon of water. With 15mm balls, a four hour mill run produces great BP when using ratios based on a 1 gallon jar. Charcoal takes 2 hours from cooked sticks to airfloat.

 

Ratios used based on 1 gallon jar produces roughly 1.4 lb BP for corning or blackmatch..

 

KNO3 - 471.6 gm

C - 94 gm

S - 62.9 gm

dextrin - 6.5 gm

 

There are plenty of Youtube vids on casting lead balls/bullets that will give you a better idea of the lead to linotype ratios. For mill media usage, you want a good amount of hardness.

 

p.s. - bullet casters are generally happy with the antimony content of just wheel weights and quenching them for additional hardness if needed. Too much hardness in a bullet is not good as it will not deform enough to seat into the barrel rifling. Finding a decent (and continuous) supply of used wheel weights is a problem nowadays so bullet casters resort to pure lead and add linotype to taste.

Edited January 8, 2013 by Bobosan

[FlaMtnBkr]

A one gallon, 6" PVC jar is supposed to hold 32 lbs of lead. That is with the optimum amount of lead, which is the jar half full (I'm so optimistic). You should be able to get an approximate weight you will need for your jar from that.

[Algenco]

A one gallon, 6" PVC jar is supposed to hold 32 lbs of lead. That is with the optimum amount of lead, which is the jar half full (I'm so optimistic). You should be able to get an approximate weight you will need for your jar from that.

 

yep, I had 35lb in mine

[Bobosan]

That's the amount I have also. Take away the weight of jar and it comes very close to 32 lbs