I have been warned of zinc in wheelweights and I have tried to avoid it. But, I have no idea if I am really avoiding the zinc. I pick through the WWs and take out the shiny ones (someone told me to do this). Am I wasting my time? Can the zinc be skimmed off the top of the melt? Before fluxing? After? Help.

Bullie,

Zinc is much harder then the alloy in a wheelweight. One way to determine if you have a zinc WW is drop it on a concrete floor and compare the sound when it hits to that of a WW that you know is not zinc. You'll probably hear a "ring" sound when the zinc one hits the concrete. You could also try a scratching a suspected zinc wheelweight. They are much harder to scratch then an alloy weight. Now as far as melting if you turn your melting pot temperature down to just a little above the melting point of lead, the zinc will not melt and will float to the top, which you can skip off. Some wheelweights are painted with a paint to approximate looking like the alloy wheels they put on most the new cars today. All of those I've found were normal wheelweight alloy inside. Another test has just come to mine. You can bend a normal weight, but a zinc one won't bend much, as they are brittle and break.

To give you an idea of what zinc is and used in, remember the old carburetors that looked lead color (some were gold colored like Gm Quadrajets), well those are made from zinc. Not to be confused with the old Carter AFB four barrels, those are aluminum. Also back in the much older days hood ornaments were cast from zinc then chrome plated. So you can get an idea of hard zinc is.

Joe

Or just check out a US penny. They are made from zinc with just a copper flashing on the outside.

Zinc melts at about 200degrees hotter than your normal casting temp. Most of the ones I've seen were the little squares and were taped on.