Test for zinc

[olafhardt]

I haven't tried this but I know zinc reacts vigorously with hydrochloric acid releasing hydrogen gas, lead does not, iron and steel do. But they stick to a magnet. So use the magnet, chunk the iron and steel, scrape the nonmagnetics with a file, add a drop of acid. If it fizzes its zinc. Hydrochloric acid is also sold as"muratic"acid for swimming pools and concrete(I think) atWallyworld, Lowes, Ace et c. Sulfuric acid gives problems.

[gray wolf]

I don't worry about the FE. it will float and I don't think it can hurt anything.
Side cutters work for me. Once you find a Zn weight save it for a sample.
You just can't cut them like a none ZN weight. Try scratching one also, then do a normal one.
There is a big, big, difference and it's hard to make a mistake.

[HammerMTB]

I was sorting some time ago and dropped one on the concrete floor. The difference in the sound is pretty distinct. Since I have found that most Zn weights are marked Zn. But if you are not sure, just drop it. If it goes thud, that's Pb. If it goes "ting" that's Zn.

[selmerfan]

I'm still trying to figure out if you guys that sort COWWs are doing hundreds of pounds at a time. I'd go insane checking each weight with a sidecutter when I have 5 or 6 buckets of WWs. I just start the burner and pot, put in half a pot, stirring regularly until they get mushy, then turn down the heat until it turns beautiful silver and the trash, including zinc weights, floats to the top. Then I continue adding a couple handfuls of weights at a time to the melt, stirring, fluxing, and skimming until I have a full pot. Then I pour ingots until I have a couple inches of alloy left, then start adding and stirring again. The temp never goes over 700 degrees, the zinc doesn't have a chance to melt in my pot. I do separate stickies, but that's easily done when grabbing handfuls of weights.

[gray wolf]

I'm still trying to figure out if you guys that sort COWWs are doing hundreds of pounds at a time. I'd go insane checking each weight with a sidecutter when I have 5 or 6 buckets of WWs. I just start the burner and pot, put in half a pot, stirring regularly until they get mushy, then turn down the heat until it turns beautiful silver and the trash, including zinc weights, floats to the top. Then I continue adding a couple handfuls of weights at a time to the melt, stirring, fluxing, and skimming until I have a full pot. Then I pour ingots until I have a couple inches of alloy left, then start adding and stirring again. The temp never goes over 700 degrees, the zinc doesn't have a chance to melt in my pot. I do separate stickies, but that's easily done when grabbing handfuls of weights.
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The above quote is a very good way to melt the WW and I use it myself.
But for an unsure beginner he/she may want to check them first and then work up to the way mentioned above. May I say you can also use a thermometer if you are unsure.
Just keep the melt below 700* I melted a bunch yesterday, they got slushy at about 550*
and were nice and fluid at 600* Pure takes a little more heat but if it's all pure then no ZN is present.