19 replies to this topic

[sasman]

Hi
I have spent the last few days preparing the raw materials for my milling media.
Just some WW(lead wheel weights)..
Now that im just about to start casting my lead balls (lee bullet ball mould .690 cal)..i have read more carefully the postings on lead contamination..i dont like the sound of it?...
I have done a little more research and have decided the problem can be solved by the addition of antimony? so i have just orderd 2kg to Hopefully harden my Balls!!!
Im hoping this will lessen the wear on the lead balls so that the BP wont be so contaminated with lead...I had cast a few balls and noticed the balls could be used as a pen!
I remember reading some were on rec pyro that if it can mark paper then its got to contaminate the material its grinding?(white KNO3 to grey KNO3)..one report said something like 200grams went in to the jar 215grams came out!.. that is serious contamination..I intend to use steel balls to grind the individual chemicals first. then use the lead to do the final mix..passfire states 24hour meal in 5 hrs! final mixing of all 3 components takes one hour..that should keep lead contamination to a miniumum..This may seem over the top but i think in for a penny in for a pound?.....
i will post my results in the next few weeks orso....(Im waiting for a tree surgeon to supply me with some Willow tree off cuts which he said should be chopped up in the next 2 or 3 weeks).

sasman

[phildunford]

I would not want to belittle the lead contamination issue, but certainly for BP I have had no problems whatever and I've made loads of the stuff!

If there was a serious problem, I'd expect the balls to wear away, and that does not seem to be the case...

[alany]

Tyre weights are typically already hardened as well.

You'd be better keeping the antimony for pyro uses.

I use fishing sinkers for BP milling media and notice no significant wear.

Edited by alany, 11 February 2004 - 02:06 PM.

[sasman]

...... I thought i had added a reply to this thread months ago?...If any1 is intrested i bought 2kg of Antimony which i used to harden the lead,
,i figured the WW(wheel weights) should contain some antimony reading various posts on the internet the aveage Antimony content is about 5%..But on melting the lead lots of the Tin & antimony is lost in the surface scum, so that was another good reason to add antimony,
.............. i added 1.5 kg Antimony to my 15kg of lead WW. I also added about 1kg of tin as i read that its the tin/antimony reaction that actually makes the alloy hard ,adding antimony without Tin would be a waste ot time!...StepToe and Son?here is a photo of gas burner and old aluminium pan ..
....The melting point of Antimony is much higher than lead/tin and trying to dissolve/melt antimony was not possible with the gas stove i was using it just could not get hot enough..So i opted to melt a small amount of antimony first in a old soup tin once that had melted i added some tin and then gave it a good stir then i added this directly to the molten lead..i repeated this process until i had used all my antimony/Tin
........The pan was not big enough to hold the entire 15+kg of alloy so i poured some in to an old biscuit tin lid to make large flat ingots..I then cast the media into a Bullet mould .690 Caliber..It took a few pourings before the mould was up to the correct temprature...Here is me casting a ball Casting a ball

.....Heres a closer look Close up
....Here is the cast ball Ball

......Ball in mould
.....Here is the end product 30 lbs of media..Nice Shiny Balls
....Dont they look Luverly ...More Nice Shiny Balls
.....errr...Ok enuff shiny balls..
Now the cast balls had a small sprue of flat lead but once i tumbled them in the ball mill for an hour they came out as perfect spheres..
...Now my next project is to make a bigger better ball Mill...

sasman

[Richard H]

An excellent post Robert! All of your photo's and video's are a wonderful resource.

[bobconan]

Hmm. My potassium nitrate and strontium nitrate both came out grey. Im just using various lead fishing sinkers. ANyone think Bismuth would work? Im not sure if lead has any effect on the various salts im powdering with it Or the resulting comps i use those salts in...

[Kembang Api]

Sasman : like the way you look into the contamination and making the milling media. Good work an excellent engineering.

I had been using ceramic ball in various size. this is the media that used by those ceramic tile producer. Maybe you could use it as an alternative milling media.

[Pyromaster2003]

That is an excellent post on milling media, great pics too. The best pictures of making lead balls iv seen! Must of took quite some time to produce all them balls?

Edited by Pyromaster2003, 07 June 2004 - 07:58 AM.

[Stuart]

Sasman, those are absolutely amazing. They are very nice I must say. Did you get the ball mould from a gun smith?

[Nate]

Myself and a friend (Bobconan on the forums to be exact) took a bar of antimony,tin,and lead today and melted it down and made milling media by drilling 9/16th holes in a piece of wood and then filling the holes with the alloy. They did not come out as perfect spheres as his did, they arent round at all as a matter of fact,(although it was rather interesting trying to get them out of the wood) they look more like bullets than anything. They seem like they will work and they were not difficult to make.We haven't tested them yet but they should work well. Do you think the tip will cause any problems with everything else?

[Stuart]

No, it will probably be rounded off with milling.

[Kembang Api]

The purpose of making antimony, tin and lead is to produce a lead alloy milling media. It will be very hard for the edge to get rounded. If the ball mill is a PVC or HDPE plastic drums. I think the edge should be okay. Otherwise is not advisable to try.

[bobconan]

I think not being perfect spheres but instead cylinders will help actually. It should be more aggressive and be more of a tumbling then rolling like putting a lifter bar in the canister.

[Jerronimo]

I was going to use solid brass rod for my millingmedia, but after calculating the amount I will roughly use, I realized it will be wayyy to expensive.

Instead I will use copper or brass tubes, cut them to length and fill them with lead.
That way will save me a lot of money and the trouble of getting antimony metal.

Has anyone have any experience using this method?
I come to realise that the brass rod after repeated impact might brake.

Edited by Jerronimo, 15 June 2004 - 06:16 PM.

[thewildething]

The thing I have found with the lead in the tube idea is when the lead cools down it contracts, leaving the lead too small for the tube, then it either wobbles around inside or falls out. Anyone ever found this??
I was using 22mm copper pipe though, but a hard smack with a hammer tends to make the lead more secure.

Marcus.