Zinc?

DMC · #1 09-09-2002, 04:55 AM

I'm not new to reloading, but fairly new to casting. I read that even trace amounts of zing will ruin cast bullets. Why? What does it do to the alloy? With some wheelweights having zinc as a coating, it's cut down on my supply, although I figure I can probably seperate the lead from the zinc with careful application of heat from a torch.
DC

imashooter2 · #2 09-09-2002, 07:27 AM

Zinc has a melting point more than 150 degrees F higher than lead or lead alloy wheel weights. You should be able to just skim them off the top if you control the temperature of your melt.

Lloyd Smale · #3 09-11-2002, 01:56 AM

its an overrated problem Ive casted thousands of pounds of wheelweights and have never once ran into a problem with zinc. I dont seperate anything they all go into the pot. If its there and its a problem theres not enough to worrry about.

DMC · #4 09-12-2002, 04:35 AM

Thanks for the replies guys. Lloyd, you told me what I really wanted to hear. I've got a bunch of wheelweight with some zinc that I want to use. Now, I'll go ahead and use it.
DC

Contender · #5 09-12-2002, 01:24 PM

Zinc will increase the surface tension of the molten alloy and thus can cause problems with good fillout of the mold no matter what you do.

Here in the NE it seems we are experiencing some real contamination in the WW alloy by both aluminum and zinc.

I have a good sized batch that is contaminated with aluminum. As the alloy cools, there are globules of metal that appear to show a migration of the rest of the alloy away from these areas.

With WW's I will typically keep it in batches and separated to avoid contamination of my other alloys should it prove to be after casting.

One can usually tell of contamination in the WW's themselves by examining the fillout of them in their WW form. If you see fissures or cratering or slumping in them, chances are the alloy they were made from was contaminated with either aluminum or zinc. If they appear smooth and well filled out, chances are they are OK. I've found that the shiny or dull appearance method is unreliable for discerning contamination.

FWIW

Regards

MikeG · #6 09-12-2002, 06:48 PM

Ahh - that would explain all the free bullets that you sent me!

(just kidding).

One of these days I hope to have time to load & even shoot some of them...