Capt. Montgomery Little Posted January 1, 2011 Share Posted January 1, 2011 Was casting lead bullets yesterday and found quite an accumulation of a greenish yellow powder in the "pure lead" pot after casting about 100 bullets. The more that were cast, the more accumulation there was. Anyone have an idea as to what was going on? Link to comment Share on other sites More sharing options...
Captain Woodrow Cahill, SASS # 54363 Posted January 1, 2011 Share Posted January 1, 2011 Howdy Captain - Were you melting reclaimed shot? From your description, it could be arsenic. It's sometimes added to lead to slow the cooling process and allow the shot to form into a more uniform shape and make it a bit harder than pure soft lead. Link to comment Share on other sites More sharing options...
Capt. Montgomery Little Posted January 1, 2011 Author Share Posted January 1, 2011 Not reclaimed shot but lead used in stained glass window production. Link to comment Share on other sites More sharing options...
Garrison Joe, SASS #60708 Posted January 1, 2011 Share Posted January 1, 2011 Not reclaimed shot but lead used in stained glass window production. A yellowish-green oxide of lead can form on your pot walls. Make sure you are not casting at too high a temperature, flux with a good casting flux occasionally (I use either borax powser or parafin wax from old candles), and for sure watch out for any Calcium contamination from modern car battery lead alloys. I understand that zinc chloride has often been used for fluxing lead soldering - zinc should not be picked up by the lead alloy, but it sure would be possible to get melting pot corrision from zinc cholride, so if you are the glass worker, you might use a zinc-chloride-free flux for your work. Arsenic is fairly hard to oxidize once it is alloyed into lead alloy. Same for antimony. Tin can oxidize pretty fast, but then, preventing that oxidation is one reason to use a reducing type flux like parafin. In general, keep your lead temp down below 800 deg F and you should not have much to worry about. Good luck, GJ Link to comment Share on other sites More sharing options...
Capt. Montgomery Little Posted January 1, 2011 Author Share Posted January 1, 2011 Thanks for the replies. It appears that the "powder" is coming from the "came" I used to melt. Just learned today that "came" is the lead strips used in stained glass work and if melted at a high temp, this will happen. Just flux w/parafin and it should go away. Never too old to learn something new and when I get old, I will appreciate that even more. Link to comment Share on other sites More sharing options...
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