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I wasn’t getting a nice silver sheen, like I usually do. It was looking pasty.
Source was wheel weights sitting in a back yard from when I thought zinc was used.
With lead melting at 622F and zinc at 786 F, shouldn’t zinc float to the top prior to melting? Also, if it’s less dense than lead, shouldn’t you be able to skim melted lead off the top?Attachment 324483
Zinc floats up like you'd want only if you bring the heat up slowly, and don't be bashful about stirring the pot.
Often when contaminated, the pot sort of looks like you put gray oatmeal in it.
And yeah, to the casual observer, that looks like what you have there.
Use your diagonal cutters and try to cut off or nip off little pieces. If it is not possible to cut it or nip it with strong bites from the Cutters then it is zinc.
That was an extre step I didn’t think I needed.Quote:
Originally Posted by Recycled bullet
I suppose the question is then, when did they start making zinc wheel weights? And why? If just lead, it makes it better for us, but I imagine that’s not the manufacturer’s overriding concern. I’m surprised they don’t just mark the zinc ones Zn, as when cast?
These wheelweights cane from a gunsmith friend who had retired when he said Clinton forced him to. In his backyard at least since then, so mid 90s or earlier.
your photo doesn't necessarily tell me you have zinc contamination, it tells me you had trouble keeping the temperature hot enough. Was it windy where you were melting? Did you have a thermometer in it, when it was liquid?
get some muriatic acid (used on pools) Put a few drops on your metal. If it bubbles, there is zinc present
Its hard to tell what you have with the steel clips still in it. Did you ever fully melt the lead and flux it or were the wheel weights just starting to melt and you stopped?
I now think I was having trouble getting to the temperature I needed plus was low on propane. Ran out, and with a refilled tank, it’s quite a difference.
The amalgamation in the photograph has since been recycled.
And so, I’m what year was the first zinc wheelweight marketed?
Zinc wheel weights have been around for quite a while. Exactly what year I don’t know. If you were melting your wheel weights with a standard turkey fryer you probably didn’t have sink melted in. Probably just ran out of gas and didn’t get everything melted. It’s not like it will come up to temperature to melt zinc instantly and yes once the lead was melted you would’ve seen the zink wheel weights floating on top. I’ve been doing this quite a while and I’ve never actually had any zinc wheel weights melt in with my mix. Then again I do sort my wheel weights so who knows. There is a way of removing zinc from your melt if it does occur. It requires the use of sulfur. Garden sulfur Works. Unfortunately it’s not pleasant, it’s time consuming, and you have to weigh whether it’s actually worth it.
Its likely not zinc if it melted @ less than 700deg. More likely just crud from other contaminates. Try aggressive fluxing, skim & toss the dross. Yes the zinc wts will float up.
Or acid type toilet bowl cleaner. You might already have some.Quote:
Originally Posted by CastingFool
Wayne
Lead wheel weights have been on the outs for a long time. Anymore when I get a 5 gallon bucket of WW 2/3 or better are zinc.Quote:
Originally Posted by mrcvs
It might vary from State to State, I don't know what State you are from, but I can share my experience in MN. I've melted COWW from 70s and 80s that I got from an old timer, not a zinker in there. I started scrounging COWW from tire shops and auto-salvage yards in 2009 and rarely seen a Zinker. Then in 2013, the State of MN decreed that all WW used on State owned vehicles must be Lead-free. That's when the tide turned for MN, any tire dealer putting tires on those cars/trucks weren't gonna stock both Zinc and Lead WW's. I think it was three years later, MN passed a total ban on Lead WWs, but most tire shops had already switched, as they seen the writing on the wall. I quit scrounging COWWs around 2017, because too many Zinkers and Iron in the mix.Quote:
Originally Posted by mrcvs
Zinc wheel weights have been around for at least 50 years. At least, that's when I first ruined a pot of alloy because of it.
Shaving COWW with a Utility knife.
Lead ones, you will get a smooth cutting action, and asilvery sliver will result
Zinc, the Utility knife will "chatter" . TRY IT
Much easier than a side cutter technique
beltfed/arnie
If the zinc is alloyed with the lead its melting point may be lower. Think solder alloys.
Idz,
I seen a chart somewhere (maybe a Lyman manual?). The melt temp of Lead-Zinc alloy is a bell curve, with the 55-45 mix at top around 1500º F. Of course our Lead is usually alloyed with Sn and Sb, so if some of those were in there, that would have another effect on melt temp.
I found this online.
https://www.researchgate.net/figure/...ig15_215730693
I have no idea what year zinkers were introduced ... but every wheel weight I get ...
gets tested with side cutters . One day someone going to figure out what we can do with these stinkin zinker's ... !
Gary
Quote:
Originally Posted by Idz
I always thought alloying with zinc generally made the melting temps higher. The graph JonB posted bears that out, and keep in mind that the temperatures shown are degrees Celsius.
Alloying with TIN does indeed drop the melting point, useful for soldering. ;-)
I didn't see zinc or steel until the 90's. I was segregating COWW.s and SOWW's and then seperating painted and unpainted SOWW's.
zinc will float to the top--skim and get on with casting or making ingots
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
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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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.Quote:
Originally Posted by CastingFool
Ok great [emoji108]. 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. [emoji16]
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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?
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.
I doubt it.
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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.Quote:
Originally Posted by Jeff Michel
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!
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.
It doesn't, they float out at 700degQuote:
Originally Posted by Idz
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.Quote:
Originally Posted by frkelly74
I wouldn't bother.Quote:
Originally Posted by frkelly74
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.
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)
I found out the hard way.Quote:
Originally Posted by sureYnot
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.