Another mystery lead question

[fatelk]

I looked through the stickies a bit but couldn't find what I was looking for.

I've had four 25lb chunks of "mystery lead" for a couple years, finally thought I'd melt them into usable ingots. Three of them were bricks and turned out to be some kind of low-temp bismuth alloy.

The other one was a "pig", and I was finally able to melt it into my Lee 20lb pot a bit at a time. When I got the last of it melted there was a whole bunch of "crunchy mush" on top. I thought "dang, zinc".

I skimmed off the mush and smelted it separate at a higher temp with a propane torch. I was able to get a pound out of it and melted it into a separate ingot. It melted at a higher temp, but not as high as zinc, it seemed. The funny thing is that the ingot is not hard. It seems soft, almost like pure lead.

The rest of the pot I cast into ingots and they are fairly soft too. The odd thing I noticed it that when pouring the lead into the ingot mould it seemed to have very minimal surface tension. Normally the lead kind of bulges up at the sides, but this stuff is just flat.

I've been casting for a long time, and have learned a ton on this site, but I'm still learning and curious about what might be in this lead.

[lwknight]

I got the same thing in a roll of sheet lead. It was dead soft in the sheet and still dead soft in the ingot as well. There was a skin on top and if I skimmed it off , it came right back. Then when I poured it into ingots I noticed that the surface tension was a flat zero.

Also I'm a fanatic about my beautiful 25 pound lead bricks so I often pass a propane torch flame around the edges to make all the little burrs smooth out and it also reduces any skin back to perfectly shiny alloy. Well , not this stuff. The skin was not affected at all by the reducing flame at all, plus the edges stayed square and flat instead of the nice rounded edges you normally get.

I have not tried to cast with it yet so I can't know if it will make good boolits or not.
The specific gravity is that of nearly pure lead , so its definately not tin.