How to tell if lead is contaminated with zinc

[Ray Settanta]

I want to start casting round balls this winter and I have been given about 2 hundred pounds of lead ingots cast from a Lyman ingot mold. These were cast about 25 years or more ago and no information is available as to exactly what metal is in these ingots. Looks and feels like lead but because of what I have read here about zinc contamination, I am hesitant about casting without finding out what I have. How can I find out if there is any zinc contamination?

[Daryl]

Ray - if 25 years old or older, they are unlikely to contain zinc.

Dropping one on a concrete floor, or smashing 2 together - what's the sound? - any ringing shows hardened lead pof some sort

- maybe or maybe not zinc - not likely zinc if 25 years old.

It could simply be WW alloy or Lino or some other blend, good for modern rifle bullets or balls for a SB or undersized

cast round balls for a rifle with thicker patches.

Use a lousy junk mould and cast up a few balls or bullets.  Zinc will increase the ball or bullet hardness considerably.

If you are a good bullet or ball caster, you will likely see how well they fill out in a properly heated mould

and thus know if the lead is OK or not.

[P.W.Berkuta]

Put one of the ingots in a ladle and heat it and flux it - if it is lead it will melt to a very smooth surfaced liquid -- if it is contaminated with zinc it will look like "puffy - lumpy clouds" floating on the surface. Since the ingots you have are over 25 years old they are either pure lead or range lead from modern cartridges. Did the original owner shoot muzzle loaders or modern guns?

[Ray Settanta]

Thanks for the replies. That should get me started. The original owner did not shoot muzzleloaders.

[Ray Settanta]

Daryl, Looked up Lead Bullets Technology and found a hardness tester for sale at $100.
Is this the one you were talking about?
http://www.lbtmolds.com/hardtester.shtml

[Brokennock]

Is there a known weight for a pure lead ingot from a Lyman ingot mold? Weigh and compare?

[Joe S]

Pure lead melts at 621.5°F.  If your metal melts at some other temperature, it is an alloy.

[TN Longhunter]

The old test is if your fingernail will scratch it, then no hardening allow present. 

[Mike from OK]

Just how accurate is the fingernail test?

Near my home there is a flea market. One of the booths has cast lead ingots for sale. I can pick them up and use my thumbnail to scratch a decent gouge into the ingots.

But I have not bought any yet for fear that they may not be pure lead.

Am I being too paranoid about this?

Mike

[Daryl]

Daryl, Looked up Lead Bullets Technology and found a hardness tester for sale at $100.
Is this the one you were talking about?
http://www.lbtmolds.com/hardtester.shtml

That's the one, Ray- grab it.  They were $125.00 back in the late 80's - or maybe that was landed here.

[P.W.Berkuta]

I have the Lee tester and it is a pain to use -- I think I will be purchasing one of these - thanks for the info & link .

[TN Longhunter]

Lead has a very low hardness. The keratin in fingernails is also low but will mark lead. Try it on wheel weights and either not a mark or a very shallow one.  Try a few different alloys and you will soon learn. Not a definitive test but one that will allow you to make a decision on found lead.

[T*O*F]

Cast a ball from pure lead.  Hold it at shoulder level and let it drop on to a concrete floor.  It will have a flat spot on it.  Use that ball as your standard.  Harder balls won't dent as much and the difference is easily measured.

[Daryl]

Guys - this is a book everyone who casts for a number of different guns, should have.

http://www.lbtmolds.com/books.shtml

[Scota4570]

I want to start casting round balls this winter and I have been given about 2 hundred pounds of lead ingots cast from a Lyman ingot mold. These were cast about 25 years or more ago and no information is available as to exactly what metal is in these ingots. Looks and feels like lead but because of what I have read here about zinc contamination, I am hesitant about casting without finding out what I have. How can I find out if there is any zinc contamination?

To tell if it is pure enough, drop an ingot on a cement floor.  IT it goes clunk you are fine.  IF it rings it is harder.  IT it cast like cream of wheat it has zinc.  IF it goes clunk it has no zinc.  .

Lead is now regarded as a hazardous material, yes that is stupid.  Even so, it is becoming harder to find.  Time to stock up.