Zinc

[Octaron1]

I found a supply of 30 lb lead bars, they have been checked and contain .6% zinc.
Do you folks think this will create problems for casting?

[AlaskanGuy]

Not in the least... Most lead at we cast with contains a small percent of zinc.... Cast away is my advice... Or better yet, send them to me and I will cast away.. [smilie=1:

AG

[popper]

No, buy it. You can easily eliminate it if you want.

[Octaron1]

Not in the least... Most lead at we cast with contains a small percent of zinc.... Cast away is my advice... Or better yet, send them to me and I will cast away.. [smilie=1:

AG
I didn't think it would be a problem so I just bought 180 lbs. I might get more tomorrow they have another 260 lbs still there.
Nice bars 12 to 14 inches long solid lead.

[wistlepig1]

Is 4 % Zn the magic number not to go above or has my old menory failed me again?

[bangerjim]

I started seeing things go a "little sideways" at 4-5% when I did my Zn contamination tests on cast boolits. I intentionally contaminated at 1, 2, 3, 4, & 5% levels and cast with it.

This Zn paranoia is everywhere on here! Small amounts are no reason to "throw out my whole pot" because ONE Zn WW got in 100# of Pb! This fear has been instilled in people for no real reason, other than just here-say. Many newer smelters think they have Zn when the only problem is not enough heat to melt the lead and "oatmeal" forms on the top. More heat & flux/reduce and the problem goes away.

Any degradation in fill-out I encountered with Zn was offset by adding a little more SN.

It IS always best to check all your WW's while melting to eliminate them, but a bit-o-zinc does not ruin anything. And you CAN remove it chemically as addressed on several threads on here.

banger

[mikeym1a]

I read somewhere that lead will mix with 1% zinc, with no problems. I can't remember where I read that, but it stood out in my mind. So, .6% zinc should cause no problem for you, if you will trust my memory....[smilie=1:

[10mmShooter]

According to Lyman Cast bible Zn effects surface tension of lead alloys and "castablity" all are relative terms, you have determine what an acceptable level of contamination is and at what level it effects your finished product.

[runfiverun]

arsenic affects surface tension, that's why it's used in shot.
.6% zinc is nothing.