SlippShodd
05-27-2012, 01:42 AM
Since I had the day to play, I took my time with smelting my range scrap, doing a bit of personal research along the way; pretty much reinventing the wheel, but satisfying my own curiosities. I started with 20 pounds of scrap, picked out of berms at some of the local shooting areas in the desert. I usually segregate the cast boolits from the J words and smelt them separately so I can blend my own alloys somewhat accurately. I figured this was mostly a moot point for the bulk of my shooting needs since I really only cast for handgun rounds. I have a fair stock of wheel weight and linotype alloy accumulated over the years, and the segregated range scrap has been useful for blending with those. A while back I just started smelting my range pickings all together and adding a bit of tin when casting and the resulting alloy has been more than satisfactory; something a lot of you already knew.
Today I figured I had a pretty typical mix from the ranges, but I sorted out all the cast stuff before I melted it down to get an idea of what the composition of the mix would be. Out of 20# of dirty scrap, there was 3.34# of cast in the mix. After the usual amount of fluxing, stirring and skimming, I took out 2.66 pounds of jackets and platings. I screened the dirt and ash out of the dross and added the dross back to the melt, fluxed, skimmed and poured my ingots. That resulted in 17.1 pounds of clean ingots. The resulting dross that wouldn't return to the mix weighed 3.62 ounces, and I lost 5 ounces of jackets to the magnet, leaving me with a little over 2 pounds of #2 copper to sell to the recycler. I don't have a hardness tester, but I use the pencil scratch test to determine consistency in my alloys. Just like the last batch of ingots I poured like these, the hardest pencil that wouldn't scratch was the "B", putting the BHN higher than 10 and less than 15, or somewhere around that magical 12 BHN number.
So out of 20# of starting metal, 17.1# of usable alloy (85%), plus 2.66# of jackets (13%), equals 19.76 pounds, plus almost a 1/4 pound of dross (about 1%) and I can account for most of 20 pounds; I didn't weigh the dirt :). About 12% of the jacket weight was lost to steel. A little more than 19% of the resulting alloy started life as cast boolits. I figure that's a pretty typical smelt for me, YMMV, but probably not by much.
My 20.5 cents worth, adjusted for inflation on the silver standard.
mike
Today I figured I had a pretty typical mix from the ranges, but I sorted out all the cast stuff before I melted it down to get an idea of what the composition of the mix would be. Out of 20# of dirty scrap, there was 3.34# of cast in the mix. After the usual amount of fluxing, stirring and skimming, I took out 2.66 pounds of jackets and platings. I screened the dirt and ash out of the dross and added the dross back to the melt, fluxed, skimmed and poured my ingots. That resulted in 17.1 pounds of clean ingots. The resulting dross that wouldn't return to the mix weighed 3.62 ounces, and I lost 5 ounces of jackets to the magnet, leaving me with a little over 2 pounds of #2 copper to sell to the recycler. I don't have a hardness tester, but I use the pencil scratch test to determine consistency in my alloys. Just like the last batch of ingots I poured like these, the hardest pencil that wouldn't scratch was the "B", putting the BHN higher than 10 and less than 15, or somewhere around that magical 12 BHN number.
So out of 20# of starting metal, 17.1# of usable alloy (85%), plus 2.66# of jackets (13%), equals 19.76 pounds, plus almost a 1/4 pound of dross (about 1%) and I can account for most of 20 pounds; I didn't weigh the dirt :). About 12% of the jacket weight was lost to steel. A little more than 19% of the resulting alloy started life as cast boolits. I figure that's a pretty typical smelt for me, YMMV, but probably not by much.
My 20.5 cents worth, adjusted for inflation on the silver standard.
mike