Zinc In Alloy?

[American]

Hello all. While this is my first post, I'm not new to CastBoolits and have been gathering wisdom here for a few months off and on as time permits. So, the first thing I'd like to do is express my gratitude and appreciation to all those who share info here with the likes of me.

Thanks much - I do sincerely appreciate it.

I bought about 100# of WW from a scrap yard, to get started, because I've got the bug to start casting and didn’t find any for free right off. Guess I paid about what they cost on ebay delivered… I'll try to better that in the future.

Also got a heavy old stainless steel pressure cooker bottom pot, about 8" across, a slotted spoon, and a couple non-stick muffin tins, all either free, on sale, or at local thrift stores for a buck here and there.

Today I fired up the propane camp stove, melted about 20# of WW, starting with the big, soft ones I figured were lead for sure (and sorting out stick-ons and obvious non-lead ones with riveted clips). I tried to keep the temp down so I could spot floating zincs before they could melt - but saw none…

I've seen two conflicting views on this, best illustrated as so:

Goatlips says in his "Black powder Tips" http://goatlipstips.cas-town.com/index.html :

"Here is where the dreaded Zinc weights are supposed to float up also (higher melting temperature) but I've never found any."

Never found any, in years of sucessful casting?!?!

OTOH, in the the thread here "Smelting without a thermometer" it is stated:

"If you are doing it right, you will get the zinc ones before they have a chance to melt. There ARE zinc ones.....unmarked ones at that!"

Goatlips seems to have much experience and little trouble - the boolits he casts and shows pictures of I would be very happy to cast and shoot, zinc or no zinc.

But then I read how every batch of WW has zincs in it and even a little zinc will ruin a batch of alloy for casting and it must be discarded and all equipment used to process that bad zinc-containing batch must be carefully cleaned.

So, I guess my question is: How can I tell if my alloy ingots now contain zinc or if I was just lucky and didn’t have "unmarked" zincs in my batch of scrap WWs?

[mtgrs737]

If the ingots you smelted cast nice well filled out bullets then you probably got all the zinc weights out of the batch during sorting. I sent Goatlips an email about his smelting technique using a weed burner to speed things up (which it will many times) as the weed burner will dump so much heat into the unmelted weights that it will melt the zinc ones that are mixed in. Goatlips may just have a zinc free source, however I doubt it, he may also be able to cast decent boolits with a small amount of zinc in his mix.

I prefer to not use the weed burner and keep the melt temps under 725 and insure that I get a chance to skim off any zinc weights before they melt in. If you hand sort or keep the temp down then you should not have any zinc problems.

[American]

I prefer to not use the weed burner and keep the melt temps under 725 and insure that I get a chance to skim off any zinc weights before they melt in. If you hand sort or keep the temp down then you should not have any zinc problems.

Thanks much. Already figured that about the top torching, and I'll be getting a thermometer ASAP.

Another question - I've heard that lead/tin solder melts at a lower temp than either lead or tin do seperately. Could this same effect cause the zinc to melt into the already molten lead at a lower temp than it would alone? I realize in the case of solder the lead and tin are already alloyed together, but the lead and zinc are seperate. Still, is there any of this effect going on when the metals are not alloyed yet?

[floodgate]

American:

Bill Ferguson, aka. "The AntimonyMan" our metallurgy guru, reported recently (I think it was in CBA's magazine, "The Fouling Shot", but I have passed my back issues on to a friend) that even down in the low-to-mid-600's, zinc will SLOWLY combine with a lead/tin/antimony mix, well below its normal melting temperature. But this is not a problem if you monitor "smelting"* temperature, and dip them out as soon as you see them.

floodgate

* Technically - I believe - "smelting" refers to the process of reducing and separating metal oxide or sulfide, etc., ores into the pure metals; what we do with WW's is really not smelting (unless you use a potent reducing flux like stearic acid) but a preliminary melting to separate out clips and non-metallic components like rubber valve stems, tobacco juice and stray lug nuts; and if we're careful, zinc weights. But everyone here knows what we all mean by "smelting" (just as we use the term "boolits"), so I won't be a "dead piss-ant" (i.e., peed-ant) about it.