Quote:
Originally Posted by Javelin
I bought about 75 lbs of soft lead from a metal recycler and when I melted it down, it had alot of blue and copper stuff floating on the top. I would scoop it off then in a minute or two, more copper looking stuff on top. I never seemed to get it all of, it would just keep coming back.
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That "copper and blue" stuff is composed of oxides of lead, and is
not caused by any contaminant in the lead. As a matter of fact, that copper and blue stuff is a good indication that you have fairly pure lead with
no contaminants or significant alloying elements. If the lead had any significant alloy components, it would not likely turn that characteristic color.
What happened, simply, is that the lead was overheated. And that's why the copper and blue oxides just keep coming back. You can't scoop the contaminant off, because it's just lead that you're removing. Even if the lead is 100% pure, when overheated it will turn yellowish, and then coppery or blue.
Solution: Just reduce the heat a bit!
Quote:
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When I finally poured it into ingots, the ingots didn't have that brilliant 'silver-chrome' look to them, but more of a blue hue to them. Is this lead worth saving?
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Again, what you're seeing is the lead becoming oxidised a bit. If you reduce heat slightly, and flux before pouring ingots-- which is the proper procedure-- the ingots will be shiny. The hotter ya get 'em, the less shiny they'll be. Yup, the lead is worth saving.
I know it's common to blame anything unexpected on "contaminants" in lead, but I'm sure someone with a lot of lead pouring experience will confirm my advice here.
Be safe and best of luck!
