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View Full Version : Yes, with Zinc in the alloy you can cast bullets



John Boy
05-28-2020, 08:05 AM
Lyman, Cast Bullet Handbook, 3rd Edition - page 44:


For example at 850 degrees, which is in the normal range of bullet casting temperatures, lead will dissolve a little over 2% zinc. If more zinc is added, an immisicible melt is formed and a puddle of the lower density zinc liquid will form on the surface of the molten lead, and no amount of stirring or fluxing will make it disappear. If the temperature is raised, the solubility of zinc in lead increases and the zinc puddle will gradually dissolve. At 1468 degrees, zinc and lead are completely soluble in one another but on cooling, any alloy containing more than 2% zinc will again separate to form two immiscible liquids

Save those zinc wheel weights :castmine:

rancher1913
05-28-2020, 09:15 AM
you need to dig a little deeper into the info before preaching. yes zinc will desolve in lead, thats why we strive very hard to keep it out. yes you can cast boolits from zinc contaminated lead, but look at your last part of your post, the zinc and lead will separate upon cooling. this will give you an unbalanced boolit that will not fly straight, do you really want to use unstable boolits. the only way people have found to use zinc is as pure for boolits were lead is outlawed, some are haveing good luck.

joe leadslinger
05-28-2020, 09:40 AM
As long as you keep zinc at less than 2% of the mix it will not separate from the mix. The only benifit from adding zinc is a increase in BHN. I'm sure their are more than would like to admit it that have a little zinc in their ingots. IMO.

Shiloh
05-28-2020, 12:28 PM
Saw a posting about adding sulphur to the melt. I did it. The cottage cheese slag floated to the top. I skimmed and repeated. The alloy started throwing good bullets.

I have my suspect contaminated ingots quarantined. Probably go to the recycler.

Shiloh

djryan13
05-28-2020, 01:59 PM
I did the same. Got some bad lead on EBay. I am guessing it was Zinc but apparently Sulphur can flux other things too. Regardless, my lead started casting good after that.

Smokes really nasty and fumes acid so wear an acid mask.




Saw a posting about adding sulphur to the melt. I did it. The cottage cheese slag floated to the top. I skimmed and repeated. The alloy started throwing good bullets.

I have my suspect contaminated ingots quarantined. Probably go to the recycler.

Shiloh

popper
05-28-2020, 04:02 PM
zinc and lead will separate upon cooling. Only partially. It adds hardness and yes I've shot 1%Zn in 40sw, works fine, expands well.

wnc435
05-28-2020, 06:00 PM
The 2% rule is true most W/W have some zinc in them already just usually not over 1% To get rid of excess zinc I do not use Sulphur I slowly heat until liquefied don't stir or add flux then skim off zinc slurry from top. Then stir and let sit until it isn't moving then skim off. I do this several times then pour into ingots you may have to do this several times depending on how contaminated the mix is. But don't flux until you have a mix that doesn't have a separation when stirred. I have had to do this to several hundreds of # lead people have brought to me to make shot out of.

tmanbuckhunter
05-29-2020, 05:32 PM
I just don't understand it. There are so many other sources of lead and alloy out there, that to me, it makes no sense to run the risk of contaminating everything with Zinc. Wheel weights aren't even a consideration for me anymore.