25 replies to this topic

[phildunford]

Thanks Spanner, I do my best...

That's an interesting article. As I read it you will only get additional hardness if you use a lead alloy. You certainly get a harder alloy by adding a proportion of antimony. To be honest, I've never gone down this road, as I've been using pure (ish) lead balls for many years now and they show no sign of wear and if they do contaminate the milled material, it's never been enough to cause any problems.

[spanner]

Yes, the article does call for lead alloy, specifically wheel weights.

From other discussions- at rec.pyro, I believe- there was anecdotal info that pure lead would also benefit, but take that info with a grain of salt.

Judging by how your lead filled the mold at first, it would seem you have relatively pure material, at least not much tin. Good idea none the less, to enlarge the fill holes.

[bill]

http://www.unitednuclear.com/mills.htm

[PyroCreationZ]

I have now bought lead balls from cooperman twice and I'm very satisfied. Nice round lead balls so if you want to buy some I'd say take a peak on his website.
However, if you are able to make them yourself you can try that way.
Good luck!

[king lerock]

hey guys im also looking for a media i have checked out the suppliers and was wondering if i am getting a rock tumbler that apparently goes 50-60rpm(i know its slow but it should grind black powder evntually )and has two 1and1/2lb jars, should i get a ceramic media from inoxia or led from cooperman and what size. also is their way to grind a metal like Mg as i have a load of cource powder that i would like to refine.

[PyroCreationZ]

hey guys im also looking for a media i have checked out the suppliers and was wondering if i am getting a rock tumbler that apparently goes 50-60rpm(i know its slow but it should grind black powder evntually )and has two 1and1/2lb jars, should i get a ceramic media from inoxia or led from cooperman and what size. also is their way to grind a metal like Mg as i have a load of cource powder that i would like to refine.

A bit late reply (haven't been too active recently) but as an answer to your question I'd buy them from my man cooper.
I'd say contact him and he'll tell you what type you can use, what size you need, etc.
He's very helpfull!

Then again, you probably already have media by now...

[michaelp]

AdmiralDonSnider pipped me to the post on this one!

I've just discovered sinker moulds as well. I've always cast my own media, but as I made the mould by machining aluminium bar with a ball nosed end mill (which most people don't have the equipment for) I never bothered to write it up.

The sinker moulds come in several sizes, the only snag is that the there is a horizontal hole through the mould (to take the line I guess), but you could easyly block this at the ends with a bit of wood or fireclay - I'll probably screw a bit of metal bar in.

Experiments in progress, write-up on the greenman to follow soon...

PS here is the ebay shop I got mine from - I got the 44g size which come out about 3/4 inch

Sinker Moulds

Not having a gas hob i was wondering if anyone knows if this would work, filling a bbq briquette starter chimney with briquettes and sitting the saucepan on that when its good and hot, any thoughts anyone?

[cooperman435]

Yeah chrcoal will heat lead to melting easilly, just be sure youve got good ventilation to it or the pan cools it down through lack of oxygen

[michaelp]

Yeah chrcoal will heat lead to melting easilly, just be sure youve got good ventilation to it or the pan cools it down through lack of oxygen

Thanks, i will do it in between the burgers lol

[Deano 1]

If anybody is interested, I sell lead balls on ebay everyday. I do 11mm and 12.5mm constantly and I do 22mm to order. I personally use a mix of all 3 and get fantastic quick milling results.

If I'm allowed here is a link

http://www.ebay.co.u...984.m1586.l2649

[bangkokpyro]

I would worry about the safety of most ceramic and would never consider using it myself. Go with lead, safer, longer lasting and all told a far superior
milling media than ceramic in my opinion

Steve Young sells top quality hardened Lead ball media 1/2 inch Diameter and ships worldwide.
Most lead ball media is around 18 hardness (Brinnell) his is 25 to 28 Brinnell
I bought a few kilos a year ago and after hundreds of hours millng they have no apparent wear on them. Highly reccomended!
leadball@brightdsl.net