Strange Lead Questions

[bbs70]

Last week I got a small amount of unknown lead scrap from the local scrap yard.

Today I had the time to melt it into ingots.

Since most of it looked like someone at one time had melted it I decided to keep it seperate from my good lead.

QUESTION#1
One piece about 5 inches in diameter and 2 inches thick just wouldn't melt.
I took a benz o matic torch to it with no affect.
Then I put it into the melting pot with some other unknown pieces of lead, while the other lead melted around it, this piece just stayed there.
I finally got tired of playing with it and took it out of the melting pot.

Does anyone have any idea what this piece could be?

QUESTION#2

In a different pot of lead I had to turn my turkey burner up quite a bit to get some of the pieces to melt.
I got to thinking zinc contamination.

When I poured this lead into ingots, it took quite a while for it to set up to where I could dump the ingots out of the molds.
This was done outside at 34 degrees with a high velovity fan 1 foot from the molds (3 of them ) to cool them faster.
It didn't help, still took a while before emptying the molds.
Thinking the lead was too hot, I turned the burner almost completely off and let it sit for a while.
The pot of lead stayed fluid.
Still no difference in cooling time for the ingots.


I am at a loss, ANY input to these two questions would be greatly appreciated.
Bill

[runfiverun]

on number two, when it cooled it all went solid at once? right? it's an eutetic metal alloy like linotype.
i'd have put my thermometer in it and noted how low the temp was if it went to about 520 and stayed fluid then went solid at once thats what i'd call it [linotype]after comparing bhn and weights to a known.

[Cherokee]

#1 sounds like zinc. #2, since you have already melted it, try casting some bullets with it and see how they do, and compare the weight to the same bullet cast from an alloy you know. If it cast good, not likely any zinc in it. If it casts lighter than known casting, it has higher tin/antimony content.

[lwknight]

Melting temperature?? 63/37 solder has a temp below 400 degrees. That would have taken a lomg time to set up if it were as hot as to melt some pure lead in with it.