Something a little different

To start off with, one of my closest friends is in the junk business i.e. cars, radiators, batteries, copper wire , cast-iron and steel if you'll notice I did not mention lead that's because he gives it all to me for free. It's usually lead-pipe (the telephone company type) today he stopped at the house with a half of 55 gal. drum of flashing (roofing lead). I figured what the hell I didn't have anything better do so I decided to melted it down for ingots, about halfway through this blue and purple scum started forming in the lead pot if I skimmed it it would reappear within twenty seconds I went ahead and used flux it didn't get rid of it. When I got done tonight I took a piece that I knew had that purple stuff on it, I used my Saeco hardness gauge it was 2 that's just barely above pure lead.

I can get over how odd this stuff was it was crusty and brittle maybe one of you guys knows what it was.

I've been casting bullet for twenty years even hard ones using Linotype and wheel weights and this one is new to me it reminds me of chrome flaking off of a bumper . ::

 

My best guess is that it's a trace amount of antimony that came out of the mix. Antimony will separate if you heat lead hot enough but I'm surprised the fluxing did not make the stuff mix back in with the lead.
I've read also that some soft lead was mixed with arsenic. I don't know what arsenic looks like and would rather not know.
I doubt it would hurt you as not many people chew on the stuff on purpose.
Flatheads anyone?

 

Nearly all lead has trace amounts of arsenic in it. If I remember correctly it is added as an aid in hardening the lead when tin and antimony are introduced, but I beleive some is present anyway.

I've seen the blueish/purpleish stuff your talking about and I believe Maxi is mostly right...I also think some tin is in that stuff. If you just leave it on top it burns off to a black eventually and you can skim it off and dump it with your other slag. Obviously it doesn't hurt anything as your BHT indicated.

Vic