Tell me about zinc

[shepherddogs]

I've heard zinc should be avoided like the plague. What problems does it cause? How do you identify zinc? I cast bullets years ago but back then I don't think they used zinc for wheel weights.

[docone31]

I have zinc in my blend. I also paper patch. It is ok.
I am a smokeless paper patcher so, so far zinc has not had that much of an issue for me.
When I first discovered I had zinc, I turned the heat down on the melt. The zinc floated to the top and I skimmed most out. It was touch and go untill I did that. It made me really crank up the heat to mold.

[JeffinNZ]

Zn increases the surface tension of your 'melt' and bullets will not form at all well.

Zn wheel weights much lighter than lead equivalents and where lead makes a "clunk" when dropped on concrete Zn sounds more like a "chink". A lot of Zn weights are marked "Zn" also so that makes them easy to identify.

The melting point of Zn is much higher than Pb so if you smelt at no more than 750-800F the Zn weights will not melt and will float to the top and can be removed. I prefer to sort prior to smelting but the temp thing is a nice safe guard.

This is a photo of the last batch I sorted.

http://img.photobucket.com/albums/v505/JeffinNZ/Shooting%20stuff/IMG_0106.jpg

The bucket is Pb clip on, the tub is Pb stick on, the pile is Zn/ferrous.

The next photo is a selection of Zn and ferrous weights.

http://img.photobucket.com/albums/v505/JeffinNZ/Shooting%20stuff/100-0005.jpg

http://img.photobucket.com/albums/v505/JeffinNZ/Shooting%20stuff/100-0001.jpg