Melting and casting zinc

[Rickf1985]

Well, I went to my local tire store today and asked about their wheel weights. The woman that owns the store told me I could have all they have if I wanted them. She did mention the lead weights were very few and far between anymore. I have known these people since her father owned the store so I we know each other very well. I used to send a lot of work there when I was doing fleet work. So the guys helped me load up about 450 lbs. of weights in four extra large five gallon buckets and home I came. I am through three of the buckets sorting them out and so far I have about 20 lbs. of lead weights, at least 100 lbs. of steel weights and quite a few lug nuts.:smile: and the rest is all zinc.
So, I am thinking, that is a LOT of zinc to just send to the scrap yard and get very little for it. I do see there are some people now actually casting zinc boolits, I am not going that far but I do want to melt these down and cast them into ingots for future consideration. Has anyone done this and is there any advice out there for doing so?

[oley55]

I did exactly what you are asking a couple months ago. It wasn't the amount you are talking about, but I wanted to save a bit for future 'what if' usage or sale. My initial and still current opinion is, "never again!!!"

The stuff came out clean and didn't need much, if any fluxing and made nice Lyman mold ingots. Besides the additional heat needed and much longer ingot cooling time (multiple molds highly recommended), that stuff really, really clung to any and all of my casting ladles, skimmer spoons and etc. I spent about as much time trying to clean my tools as I did smelting.

Also it is a bit odd to have steel clips and errant Fe stick-ons sinking to the bottom of the pot. Finding and scrapping out the flat Fe weights was interesting.

Did I mention the high heat? Your best, thickest welder gloves will be needed.

Edit: here's a link to a fairly recent Zinc discussion, although not much helpful info besides my whining post. https://castboolits.gunloads.com/showthread.php?428645-Still-a-market-(demand)-for-Zinc

[Winger Ed.]

There's several folks already casting Zinc.
I picked up a Zinc rifle boolit about .35 caliber in the berm several weeks ago at our range.
From the same mold, they weigh about 60% what Lead does, but you can push them up around jacketed speeds.

Get on youtube and search 'Casting Zinc bullets'. There are several videos about it.

Not anytime real soon, but as Lead dries up, it's the future for casting.
I've thought about it for .223 in an AR if the price of jacketed goes crazy and I can't find factory seconds.

[NyFirefighter357]

Clean Zn should sell for more in ingot for either for scrap or casting alloy for bullets or other projects.

[Hogtamer]

With 4% aluminum added it casts great. These are 12 ga . 731 full bore slugs weighing 477 grns.
290946

[Rickf1985]

2 questions, what alloy of aluminum did you use and how hot did you have to go to get the aluminum to alloy in? For now I am just looking to melt the zinc as pure and keep it that way. In the future I might get into making alloys but I doubt it. I will either sell it to someone else who wants to do that or dabble in making pure zinc bullets.

[TyGuy]

I assume this is 4% by weight, not volume, correct? Since aluminum’s melting point is higher than zinc’s boiling point (IIRC) I assume aluminum will readily dissolve into molten zinc. I guess that rules out aluminum molds…

[BK7saum]

I have about 150 lbs of zinc ww I am about to melt down. I figure they will be easier to store than a few buckets or boxes of zinkers in ww form.

Just need to mark them so there is no confusion.

[BK7saum]

I believe I read that the zinc ww alloy is Zamak or some variation. Note really pure zinc to start with.

[Winger Ed.]

I guess that rules out aluminum molds…

There's another thread here in the last several days that sort of addresses that.

Zinc melts a couple hundred degrees or so sooner than Alum.
However; You'd need to get it hotter than the melting point for a good flow and mold fill out.
You'd still be under Alum.'s melting point, but the Alum. would probably be getting so soft you couldn't
bang around on the sprue plate if a boolit didn't want to just drop out of the Alum. mold.

[JonB_in_Glencoe]

The vast majority of zinc WW is ZAMAK 3
https://www.dynacast.com/en/knowledge-center/material-information/die-cast-metals/zinc-casting-metals/zamak-3

[fc60]

Greetings,

Since Zinc contaminates Lead for our casting needs, consider taking to the scrapper and trading for some Lead.

If you shoot the Zinc bullets at the local club and they recycle the backstop it will not be of much value to us casters.

Cheers,

Dave

[Rickf1985]

If you keep your lead below 750 degrees the zinc will just float on top. I always keep my temp at 700 when smelting wheel weights, that way if I have missed one or two zincs they just float and I pull them out. I have never contaminated a pot yet. You might as well get used to new metals showing up in the berms. Not just zinc but there are others out there being shot.

[RogerDat]

I assume this is 4% by weight, not volume, correct? Since aluminum’s melting point is higher than zinc’s boiling point (IIRC) I assume aluminum will readily dissolve into molten zinc. I guess that rules out aluminum molds…

Have a friend who has aluminum molds he was going to use for cannon balls, found out zinc into aluminum mold is a No-Go.