BLTsandwedge
01-11-2010, 06:27 PM
Three weeks ago at the range, an older gent (80?) gave me two 20lb cylinders of what he believed to be pure lead that had a bit of an oxide crust. He had them for decades.
I took them home and melted one down- 20lbs on the nose. Only problem was that is was oatmeal at 600f. Initially I thought it contained zinc. I cranked the temperature- as soon as it hit 650f. the melt turned to quicksilver- very, very low viscosity. Thinking 'oh, this is cool,' I ran a 4-cavity mould with it- I'd been running two Lymans for about an hour while I was melting the cylinder down, so the moulds were in-use and hot. First thing- this quicksilver stuff wasn't setting quickly. The 4-cavity I was pouring was a #401638 @ an average 174g with WW alloy. It was taking this stuff about 20 seconds to solidify- still at the same 650f. That didn't make much sense. When the boolits did come out, they were white-silver- and hard as a wedding night distal fibula. I had an idea what this stuff was. I took one of the #401638s and weighed it- 144g- 30g lighter than lead. Lastly, I tried to snip one in half with a bolt cutter- it shattered. I was fulching thrilled!
When I was a kid and just starting to cast, the old-timers used to rave about 'white metal.' It's babbitt. As in 90% tin, 7% antimony and 3% copper. That's what this stuff is. I've probably got the component percentages wrong, but in short, I've got 40lb of world-class hardener.
Yesterday at the range I into the gent that gave it to me. He confirmed that at some time in the past, he worked at a tire service shop that's long since gone. There they had a power transfer axle that spun tires- it sat on babbitt bearings. He'd picked up the bearing run-out and cast them into the cylinders for boat ballast. He'll check for me- he might have some more layin' about. Life's good.
Tom
I took them home and melted one down- 20lbs on the nose. Only problem was that is was oatmeal at 600f. Initially I thought it contained zinc. I cranked the temperature- as soon as it hit 650f. the melt turned to quicksilver- very, very low viscosity. Thinking 'oh, this is cool,' I ran a 4-cavity mould with it- I'd been running two Lymans for about an hour while I was melting the cylinder down, so the moulds were in-use and hot. First thing- this quicksilver stuff wasn't setting quickly. The 4-cavity I was pouring was a #401638 @ an average 174g with WW alloy. It was taking this stuff about 20 seconds to solidify- still at the same 650f. That didn't make much sense. When the boolits did come out, they were white-silver- and hard as a wedding night distal fibula. I had an idea what this stuff was. I took one of the #401638s and weighed it- 144g- 30g lighter than lead. Lastly, I tried to snip one in half with a bolt cutter- it shattered. I was fulching thrilled!
When I was a kid and just starting to cast, the old-timers used to rave about 'white metal.' It's babbitt. As in 90% tin, 7% antimony and 3% copper. That's what this stuff is. I've probably got the component percentages wrong, but in short, I've got 40lb of world-class hardener.
Yesterday at the range I into the gent that gave it to me. He confirmed that at some time in the past, he worked at a tire service shop that's long since gone. There they had a power transfer axle that spun tires- it sat on babbitt bearings. He'd picked up the bearing run-out and cast them into the cylinders for boat ballast. He'll check for me- he might have some more layin' about. Life's good.
Tom