Hellgate #3302 L Posted August 16, 2011 Posted August 16, 2011 OK, so today I decided to do a bunch of casting and threw in every "mystery ingot" into the melt pot to brew up a bunch of scrap lead for casting pistol bullets. I had about 6 ingots that I thought were hard lead and after the pot was melted I noticed there were two ingots that had not melted with the rest of the lead sinkers, salvaged bullets, wheel weights, etc. Rather than turning up the heat to max I decided to fish them out for fear they were zinc and if melted would ruin 20 lbs of "alloy". So, I have the two lead iced ingots and 4 more in a coffee can that seem to be hard lead but I'd like to know if there is some readily available test to tell if I have zinc or just some weird hard lead ingots. Any ideas?
Ghost, SASS #50125 Posted August 17, 2011 Posted August 17, 2011 Hellgate, I'm not sure about a test for hardness, but I do know this. Lead that is salvaged from old batteries is a lot harder and will melt at higher temps than wheel weight lead. It will also have acid in it which will give a multi-colored shean on top. Battery lead is not good for making bullets in my opinion. Ghost
Mean Matt McCord, SASS #24683 Posted August 17, 2011 Posted August 17, 2011 One easy way is to try muriatic acid. Muriatic acid on zinc will produce a very vigorous foaming reaction. On lead, it will still produce a foaming action, but much more subdued. CAUTION: Muriatic acid is a diluted version of hydrochloric acid. Wear long sleeves, rubber gloves, and full eye protection before handling it. If you don't want to mess with the acid (and I would not blame you), take your ingots and measure them to get the volume in cubic inches. Then weigh them. Lead is 0.41 pounds per cubic inch, whereas zinc is 0.26 pounds per cubic inch.
Snakebite Posted August 17, 2011 Posted August 17, 2011 Hey ... I know.. a pound of lead weights more than a pound of zinc Hummm, that may not be right.... I'll have to do some checking. Snakebite
Mustang Gregg Posted August 17, 2011 Posted August 17, 2011 The lead alloys I use weigh about 1.5#. The mystery metal from newer tire balancing weights (guessing Zn alloy) weigh less than 1#. Realistically, though- If you are melting Zn WITH Pb and you get lighter bullets, would it hurt anything as long as you get bullets that are uniform in weight? I recollect from chemistry class that Zn has a lower hardness than Cu (jacketed bullet skins). MG
Hellgate #3302 L Posted August 17, 2011 Author Posted August 17, 2011 Well then if zinc is less dense then it should have floated and these two ingots sunk. I do believe I have some muriatic (HCl) acid out in the garage. I will compare to lead sheeting and the non immersed ingots for foaming action. The battery lead (about 3 lbs out of the 20) melted right in with the rest. The bullets came out fine from the Lyman 4 cav gang mold (158311, 158gr RN). Thanks!
Old Scatterbrain Posted August 17, 2011 Posted August 17, 2011 The lead alloys I use weigh about 1.5#. The mystery metal from newer tire balancing weights (guessing Zn alloy) weigh less than 1#. Realistically, though- If you are melting Zn WITH Pb and you get lighter bullets, would it hurt anything as long as you get bullets that are uniform in weight? I recollect from chemistry class that Zn has a lower hardness than Cu (jacketed bullet skins). MG Zinc has different properties than lead, which will really screw up the casting process.
Garrison Joe, SASS #60708 Posted August 17, 2011 Posted August 17, 2011 All the Zinc wheelweights I have fished out of the lead weights, have been marked ZN with raised letters on the surface that is facing away from the open part of the clip. If the weight is not marked, then it may be lead (could still be zinc, though, so keep reading). A lead wheelweight, when dropped on concrete, thuds. A zinc weight will give a slight ring. Find a few weights you KNOW are lead and zinc, and listen to them. A zinc wheel weight cannot be scratched with your thumbnail. A lead weight, even at the top end of the antimony content for wheelweights, you can scratch a light mark into with your thumbnail. And, finally, if the weight did not melt when lead was melting (about 700 deg F), it's zinc or steel. Zinc wont melt until about 850 deg F. Steel has to be up around 2200 deg F - red-white hot. Steel weights are marked FE and will stick to a magnet (even a free refrigerator magnet). Good luck, GJ
Hellgate #3302 L Posted August 17, 2011 Author Posted August 17, 2011 These were ingots that someone else had cast into the Lyman ingot mold with the lettering on the bottom. They were not individual wheel weights.
Garrison Joe, SASS #60708 Posted August 17, 2011 Posted August 17, 2011 These were ingots that someone else had cast into the Lyman ingot mold with the lettering on the bottom. They were not individual wheel weights. OK, then, not to completely ignore the subject at hand, the fingernail test, the ring test and the melting point test still will work on the ingots. But, if the person doing the original smelting was not "sharp" enough to realize that he had some zinc weights in what he was smelting down and pouring into ingot form, then there is a GOOD chance that he has already mixed up the lead and zinc into an alloy that is essentially impossible to get all the zinc out of. Could be that there is zinc contamination in most of those ingots. If you have bullet fill-out problems, have to cast a lot hotter than normal, and can't get the melt to flux and clean up well, yep, you probably have zinc contamination. Good luck, GJ
Mustang Gregg Posted August 17, 2011 Posted August 17, 2011 Dang, I've yet to find any weights marked Zn so far. But I'm sure I have had at sometime in the past. I have accumulated over 3000# of tire weights, lead pipe, lead sheathing, linotype blocks, solder, shot, bullets, etc. Actually I try to sort out any known "light ones" or some that don't sink and/or melt nicely. I sell them back to the scrappers when I get a bucket full. Mustang Gregg
Hellgate #3302 L Posted August 17, 2011 Author Posted August 17, 2011 The bullets turned out great. The 358311 bullet is an easy one to cast with just one large rounded bottom lube groove and one crimp groove on a plain based round nosed bullet. My only concern now is whether they will lead up the barrel.
Garrison Joe, SASS #60708 Posted August 17, 2011 Posted August 17, 2011 The bullets turned out great. The 358311 bullet is an easy one to cast with just one large rounded bottom lube groove and one crimp groove on a plain based round nosed bullet. My only concern now is whether they will lead up the barrel. Zinc in a bullet alloy will not cause the alloy to lead any more than if the zinc was not there. In fact, bullets can be cast from zinc, although it is much harder to cast good ones from a zinc alloy than from our normal lead-antimony-tin alloys. And those zinc bullets are hard, and they don;t leave behind much fouling - kinda like a solid copper bullet. This latest concern is unfounded. Glad you did not end up contaminating your alloy. It is ALWAYS a risk if you use metal that you are not 100% sure what it is. Just not worth the risk, with the current cost of good lead alloy! Good luck, GJ
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