Has anyone seen this before?

[jakemo]

A buddy just bought a property near me. The former owner was a class III builder and had built a range on the property. My friend found a bunch of lead in one of his sheds and gave it to me (about 150 lbs.)! I kind of assumed that it might have been collected range lead cooked up and cast in 'cups' about the size of a small dixie cup but too big to fit in my pot. So, I cooked up some of it, fluxed it a couple of times and cast up some 'muffins'. What happened as it cooled was very strange and I don't know what to make of it. Has anyone seen anything like this before? I'm going to have to get some kind of hardness tester!

[jsizemore]

Your probably dealing with sewer pipe lead. A little more heat ( too close to the slushy phase) and a lot of fluxing, and stirring and scrapeing the pot sides and bottom.

[Rottweiler]

Yep. seen it before. That lead cooled VERY slowly. Slow enough that it started growing crystals.

Back in my early days of casting I used to smelt any and all lead I could scrounge in coffee cans set in the fire pit. I left one sit in the fire as it burned out over several hours overnight. Next day I retrieved the can. It looked like that too. Figured it had to be from the very slow cooling