using zink in cast boolits

[hodg0610]

This is interesting. I had always thought zinc would somehow ruin the pot and the molds, not just the mixture. I might have to give this a try.

[bangerjim]

This is interesting. I had always thought zinc would somehow ruin the pot and the molds, not just the mixture. I might have to give this a try.

You will not ruin your mix...................and CERTAINLY not your molds!!!!!! Many decades ago, that old wive's tale got started about a "teeny bit of Zn will ruin everything" because people got wrinkled boolits with a known Zn %. Wrinkled boolits are generally caused by just a very few things............low temp alloy, low temp molds, and novice casters. That's it. Not oil, not grease, and not Zn. And if there is Zn in there, you simply need to goose up the temp of your mix a bit and make sure your preheated molds (on your electric hotplate.....you DO use one, RIGHT?) are a bit hotter than normal.. Frosty boolits (if you do get them) are not bad. If you do not like them, just slow down your casting speed a tad and/or lower your alloy temps.

And adding a little more Sn will help also.

Good luck casting. If you ever get the urge to "throw a whole pot out" just because of a little Zn contamination, just cast it up into ingots and send to me! I will pay the USPS charge for the box. And I will gladly cast boolits with it.

[GregLaROCHE]

I would never consciously add zinc to my casting pot. However, if some accidentally gets in, can’t you flux it out by lowering the temperature, until it starts to congeal and rise to the surface?

[bangerjim]

I would never consciously add zinc to my casting pot. However, if some accidentally gets in, can’t you flux it out by lowering the temperature, until it starts to congeal and rise to the surface?

You would have to have a LOT of it to do that! And you will be scraping off most of your Sn and Sb by skimming and throwing it away.

Just do not worry about a small amount of Zn. Your best way is to do a very good sort B4 you ever melt anything.

But try it and see if it works for your needs. I never worry about Zn anymore. Haven't ever since I did the research on up to 5% Zn contamination. Just adjust the temp and cast away.

[Baltimoreed]

My first experience with zinc wheelweights was when I bought some ‘lead’ weights from a guy years ago. When I saw the box and felt the weight I thought this isn’t right. Turned out 3/4 was zinc 1/4 lead, when I contacted the guy he claimed he didn’t know-didn’t want them returned but did refund some of my money. I keep meaning to carry them to a tire place to see if I could swap them for lead. I had never heard of them living in NC. Live and learn.

[dondiego]

I have had a serious case of zinc contamination in one of my melts. I just kept adding known, good wheel weights until the melt straightened out and poured real nice. I might have increased the temp, I can't remember. It happened to me at about the time when zinc weights had just started up. I had never heard of them. Well, I melted some into my melt. It was thick but I just kept diluting it and it turned out fine. It didn't take too many pounds in a 50 pound melt.