Did I melt a zinc wheel weight in with my lead ones?

[Walter Laich]

zinc will float to the top--skim and get on with casting or making ingots

[Willie T]

For melting down wheel weights, dipping out the clips, fluxing out the crud, and pouring into ingots, a thermometer to keep the temperature down around 650-675 Fahrenheit will avoid mixing zinc into your lead. It is worth the small capital outlay. Lead wheel weights are still a thing here in Texas. My tire guy gives me one or two five gallon buckets per month. 60-70 percent are usually lead clip ons. 5-7 percent are stick on soft lead. The remainder are a mix of steel stick ons and zinc clip ons. I’ve sorted and melted a bunch of them. The clip on zinc will have raised lettering and somewhere will be the letters Zn, or they will be plastic coated. I sort them before melting. When it starts to melt it makes a gloppy mush. Keep stirring till it goes liquid and dip off the clips. If you’ve payed attention to your thermometer, any zinc that got missed in the sort floats to the top to dip out with the clips and cause no problems. Melting them that way you don’t have to wonder if you got any zinc into your lead. You also don’t get much purple or yellow oxidation film on the top if you keep the temperature down.
Willie

[vrod1023]

I melted a brick of alloy I didn't know what was in it but I did have some mushy oatmeal like stuff floating to the top which I just skinned off. Judging by the weight of the bullets I got good mold fillout so does that mean I got rid of the zinc?

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[sureYnot]

get some muriatic acid (used on pools) Put a few drops on your metal. If it bubbles, there is zinc present

But don't keep the jug near anything steel. I had a gallon in my garage, and it inspired rust on everything within a few feet.

[vrod1023]

Ok great . Yes I should have tested that dross. I tossed it in the bin will go and dig it out - haven't dumped any stinky stuff down there yet.

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[frkelly74]

how many zinkers can you get away with putting into your 20# pot before you get oatmeal? I have three or four I want to get rid of and wonder about just slipping them in to see what happens. Will an ounce in 20 pounds be noticeable?

[Jeff Michel]

Don't do it, you will never get your alloy "right" sulfur can get a majority of zinc out but it's far better not to get it in your pot in the first place. Test your metal, if you can't or are uncertain, don't use it. I've been nailed a couple times, I've probably tossed close to a hundred pounds that was zinc contaminated in the last thirty years.

[vrod1023]

I doubt it.

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[Dusty Bannister]

Don't do it, you will never get your alloy "right" sulfur can get a majority of zinc out but it's far better not to get it in your pot in the first place. Test your metal, if you can't or are uncertain, don't use it. I've been nailed a couple times, I've probably tossed close to a hundred pounds that was zinc contaminated in the last thirty years.

The most common way to deal with zinc contaminated alloy is to let it stand quietly while at casting temp and skim the dross about every 15 minutes until most of the dross is minimal. Then cast into ingots that are well marked. CAST BULLETS by E H Harrison suggests that one then fills their casting furnace half way with good alloy and add one contaminated ingot and test cast bullets for non critical bullets like fat pistol bullets. If all goes well then add another contaminated ingot. If the alloy then does not cast well, fill the remainder of the pot with good alloy. Then in the future just add one contaminated ingot to your casting furnace filling with good alloy and eventually you will use up the contaminated alloy. While some find extracting zinc not practical, it can successfully be diluted and used.

[Budzilla 19]

Way back in 2017, I was corresponding with an experienced caster here over how to use zinc to harden your alloy with out the dreaded “ oatmeal” forming.
His recommendation was .3% just to bump the alloys hardness some, turn up the heat some, and cast some really tough boolits. About 1% you really had to be on top of the sprue cutting and ramp up your pot heat some more! He said about 1.5% is where you should start seeing the oatmeal thing.
I tried the .5% thing for some step on the gas 30 caliber boolits, but couldn’t tell any difference in those rounds or the rounds cast from good ole hardball, so I put the zinc thing on the shelf. For now. frkelly74, just add one at a time, and have fun!

[barsik]

I think all the wheelweights that go back to the smelter for reuse are mixed together, without being segregated for lead alloy or zinc alloy. some of my earlier scrounged wheelweights have some zinc in them but the latest pail has a lot. I picked out as much of the pure zinc ones as I could but my ingots still came out very poor so I stopped melting them. the wheelweights from half a dozen years earlier did make bubbles when I tested them but they still made a very good bullet. I'm not collecting wheelweights any more because the amount of zinc in the so called lead wheelweights is unusable. it doesn't matter to the guy who is recycling the wheelweights if they are lead alloy or zinc, once they melt it's just another batch of recycled wheelweights. at some point the zinc/lead content will stabilize but it probably won't be anything that we could work with given the present technology and techniques of hobbyists. those are my findings, depending on where you live it may be better or worse. now I'm learning to make linotype with antimony, tin, and pure lead. I'll add more lead later to get the alloy I want for whatever purpose I need.

[fredj338]

If the zinc is alloyed with the lead its melting point may be lower. Think solder alloys.

It doesn't, they float out at 700deg

[fredj338]

how many zinkers can you get away with putting into your 20# pot before you get oatmeal? I have three or four I want to get rid of and wonder about just slipping them in to see what happens. Will an ounce in 20 pounds be noticeable?

No but why bother, just toss them. I have manaeged to flux & skim enough at lower temp to remove a lot of zinc contaminates in a pot of alloy. Flux, skim, repeat.

[Winger Ed.]

how many zinkers can you get away with putting into your 20# pot before you get oatmeal? I have three or four I want to get rid of and wonder about just slipping them in to see what happens. Will an ounce in 20 pounds be noticeable?

I wouldn't bother.
It's like putting a glass of dirty water into a gallon of fresh water....
Now you have a little more than a gallon of dirty water.

[Delkal]

While it is always best to avoid zinc contamination if it happens don't sweat about it and certainly don't toss it. Just crank up your temp, flux a lot, and cast heavy pistol bullets. A 20 pound batch doesn't last long casting 230 grain 45 bullets and zinc contaminated or not they will still shoot better than I can at 25 yards. I have not noticed a difference with a 400 grain 45/70 at 100 yards either. Save your good stuff for casting your rifle or hunting bullets.

For goodwill, and to save the planet and all that.......I would be happy to take all of your zinc contaminated lead (if you pay to ship it)

[CastingFool]

But don't keep the jug near anything steel. I had a gallon in my garage, and it inspired rust on everything within a few feet.

I found out the hard way.

[BRatigan]

I routinely sort lead wheel weights that we get from a local tire guy. The lead content is about 15-20 percent. Zinc(usually marked Zn), Iron or steel weights that are marked Fe, and lead weights are all we get. I use either a pair of plyers or the steel clip itself to dent, scratch or mark each piece that is questionable. Only the lead weights mark easily. The zinc are usually painted grey and the steel/iron weights are black, grey or silver colored. Lead weights usually are not painted. I have seen many lead weights that are flat and they bend very easily, the others are not bendable by hand.