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excess650
01-26-2011, 07:43 PM
My friends and I bought a couple of tons of cable sheathing back in the mid '90s. It came from a hydroelectric plant when they upgraded, and had already been smelted and poured into 5# Lyman ingos when we got it. I was shooting BPCRS at the time and using 20-1 or 25-1, and I have no doubt that this sheathing was pure or nearly so.

Some years later another friend worked with a guy who was recycling lead sheathed telephone cable, and asked if I wanted to buy the lead. My previous experience was that cable sheathing was excellent stuff, and the price was such that I would have been foolish to turn it down. It was smelted, poured into 3# and 10# ingots and delivered to my driveway. 2200# was more than I had anticipated needing, but I took it all anyway.

With my electric plant cable sheathing all used to make BPCRS alloy, I started with the telephone cable ingots. It didn't take me long to realize that there was SOMETHING in it, but I didn't know what. Adding tin to it made much harder than anticipated alloy.

When in need of soft lead for MLer PRBs last year, I started melting this stuff down, and rather than fluxing, I simply skimmed the slushy, gold tinted stuff from the top. When it cooled in ingot molds( the skimmed material) it was shiny and silvery. The remainder was cast into RBs, and measured roughly 9.5bhn according to my Cabinetree tester, so there was still something in the lead. I suspect there was antimony in the metal, and possibly some calcium from what I've read. Whatever, it causes the metal to cling to my ladle in thin sheets, kinda like soapy water mixture for blowing bubbles.:confused: I should mention that it seemed to seperate mostly when the ingots were melting, and not up to casting temperature. Adding anything into the pot that decreased the melt temperature caused more seperation. The metal was NOT overheated when I was doing this.

Regardless, I had the remnants to use along with pure tin, 50/50 solder, wheel weights, and recovered indoor range scrap. I was wanting to cast some soft boolits, but without adding tin it didn't fill out well, and still was roughly 9.5bhn. Today I decided to add tin to the skimmed lead, and the result was nice shiny boolits 12.5bhn 30 minutes after water dropping. I'll check them over the next several days to see how quickly and how much they harden.:popcorn:

BHN now 15 after 16 hours!
BHN still 15 after 26 hours
BHN 16-18 after 100 hours
after a week, BHN 16-18

I've saved all of the skimmed material and will eventually remelt it into a homogenous batch and have it tested. I'm betting that its high in antimony content, and there must be at least 50# right now.

405
01-26-2011, 09:38 PM
Thanks, interesting report. My primary source of "pure" lead is sheathing. It has always produced large amounts of the tan colored fluffy dross when first melting and fluxing. But it has always tested right at 5-6 BHN afterward. It has not acted weird when mixing with antimony or tin either. Curious to see what the "dross" is.

excess650
02-03-2011, 02:36 PM
I cast up a batch of 30cal "plinkers" from an old 6 cavity group buy mold. These were from the same mix as the initial post, but air-cooled instead of water dropped. 30 minutes after I finished casting the reading was 9.5bhn. I'll be curious to see how much they harden up with age.