Zinc in the lead? Ooops...maybe?

N

NateKirk

New member
So I have been getting into casting bullets and such for my BP revolver. so far I have just been making ingots out of wheel weights. Now as I'm sure you know not all wheel weights are lead- some are zinc, and steel also. Being poor I have just been melting the stuff in a big pot over a campfire (cant afford a casting furnace) and scooping out whatever doesn't melt. It has just occured to me though that the zinc could melt also, so, is it bad if some zinc got mixed in with the lead. If I cast bullets out of those ingots are they going to be too hard and damage the gun? Please give me some good news:(
 
They won't be too hard to shoot down the barrel. Zinc is softer then steel. The problem you will have is the mold won't fill out right, radical bullet weights, and probably not an even weight distribution around the axis of the bullet. I've heard that about 2% is the maximum you still don't want in a batch of lead, but castable. If possible keep it out. You can flux it out with sulfur, but I've never done it and its not very safe because it's toxic. If you smelt below 600F the zinc should float on top to be scooped off. Zinc I believe melts at 750.
 
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You don't need a casting furnace, but a decent lead thermometer would go a LONG way in keeping the zinc out of your lead, as would sorting through them to begin with. There are several easy test to determine if they are zinc or not and even if you have contaminated lead with zinc. If you go the thermometer route just keep your melt temp below 700 and the steel and zinc will usually float to the top. However, you should always start with some known alloy in the pot first before adding to it so you know what the actual starting temp is. Add in a little at a time so as not to drop the temp too much ans try to keep it constant by the addition of more weights as you go.

The easiest way to keep it out in the first place is to use a set of side cutters and after separating the possibles from the known lead weights, you simply cut into them. The lead ones can pretty easily be cut into, not all the way through but enough to know it's lead. The zinc ones, you might mark them but your not going to give them a cut, unless you have some darned good cutters and supreme hand strength.

If you do a search on the net, you will probably find several links to sorting out wheel weights I know for a fact there is a good one here,Hand Sorting Wheel Weights

While your there browse the other stickies and you will find how to test your alloy using muratic acid or drain cleaner. Sounds WAY worse than it really is.
 
Zinc melts at around 875F so there is some room. A quick temp check with a casting thermometer will let you know for sure that you stick around 600-650F. Pure lead melts at 630F , most alloys with sn and sb will melt around 550F to 600F. Lino is 450Fish.
 
Use a casting thermometer. If the melt still looks soupy at 800 it is probably contaminated with zinc.

When melting I keep temps at 750 or less with clip on wheel weights in the event a zinc weight makes its way into the melt it will float up with the clips, and steel weights. For the stick on ones I usualy have to get them up to around 800 degrees to get them to pour well.

Note make sure you melt weights outside. It releases Carbon Monoxide to melt them inside, also it makes the house smell like burned tires for days afterwards.
 
Zinc is not good for shore !

But before gettin to much outta shape try casting with your alloy & see what happens.
 
Zinc weights will float to the top of the melt before they melt down. They also give off a distinct, sweet sickening odor when they reach high temperatures where lead is pretty much odorless.
 
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