National Lead Co mystery lead

[retrobass]

Scored these two big chunks of lead a few months ago for 50 cents a pound. I believe the guy said they were used as some kinda wheel chocks, maybe for shipping. VERY labor intense to split them in half with a maul. Each weighed 60 pounds. A little chunk that flew off when chopping them tested as Aged Wheel Weight hardness. However, after I cast them, an ingot tested more like 1 in 30 hardness. I think it has tin, because they ‘tink’ instead of thud. Anybody familiar with this type of lead?

[Dusty Bannister]

Looks like the usual lead cast in "pig" ingots. The tabs on each end make it easier to pick up and stack. One problem with testing ingots for hardness is that the cooling rate is different from that of bullets. SO you are dealing with some error that you have introduced. Also, you fail to mention of the newly cast ingots have aged several weeks or tested shortly after casting. Fresh case will read softer if an alloy of lead, antimony and tin. Lead alone will be the same and not age harden. And if you do anything to speed up the cooling, you might also get a harder reading than normal.

Lots to speculate about, but you can have a sample scanned for a nominal cost and know what you have. Seeing some odd shaped pieces on the edge of the photo suggest you might have blended up some special mystery metal beyond just what the ingots were. That would normally not be suggested as a good practice. If it was contaminated, you could have contaminated your good lead ingots. Decent price on the ingots. Good luck, check with BNE for the scan. There are also others, but I have used BNE in the past.

[retrobass]

Lots to speculate about, but you can have a sample scanned for a nominal cost and know what you have. Seeing some odd shaped pieces on the edge of the photo suggest you might have blended up some special mystery metal beyond just what the ingots were. That would normally not be suggested as a good practice. If it was contaminated, you could have contaminated your good lead ingots. Decent price on the ingots. Good luck, check with BNE for the scan. There are also others, but I have used BNE in the past.

I kept these ingots separate, I like to keep my options open for alloying. I’m about to load a few up into my RCBS bottom pour and see how they behave. I will test an air cooled bullet now and again in 10 days. If it ends up being hard I will send to BNE.

Very good info about testing ingots, the cooling rate makes a lot of sense.

[retrobass]

Brinelle Hardness on freshly cast from my Lee 120 TC mold is a hair over 9 air cooled and 10 when water dropped. It casts like a dream with good fillout. I wonder if I will air cooled and powder coated will work.

Edit: cut with half COWW and a mini muffin of pewter, now running 11.5 BNH. .....SCIENCE!