Time for an update. Work is a two bladed sword. Pays the bills to allow you to play, but then interferes with playtime. About to flush out a bunch of work, which hopefully, will allow more time to play.
Anyway, have managed to smelt about 400 pounds of the wheel weights. Interesting process and not nearly as difficult or scary as I had feared. As long as you don't get complacent, not much to fear about this. The weights I found had been stored in a wash tub that was left outside and many of them were covered in water. Once moved to buckets, the steel clips started to rust. There can also be a lot of trash in those including things like rubber air stems. The first few batches, I was careful to pick all that out and try to clean them up some. Then I tried a few that were not and it made little difference. What isn't lead floats to the top to be skimmed off, including things like the rubber. Just do a gently burn (not full blast) and give it time, and they will melt and separate. Even the rubber, which has a higher melting point than the lead. Get it too hot and your lead turns a bluish gold and you run the risk of also melting things like the zinc weights. I have found a few of those and they float just like the steel clips to. As soon as I can see molten lead, I start stirring. It speeds the process along. A way to envision this is to imagine putting about 6 inches of ping pong balls in a 5 gallon bucket and piling gravel on top. Then start filling the bucket with water. The rocks will probably hold the ping pong balls down as they don't have enough buoyancy to float the rocks. But agitate it the least little bit and they will pop to the top and the rocks will sink. Same with lead and the steel clips. Stir it just a bit and things will go much faster. Funny to see those heavy steel clips bobbing around on top.
Second part is the need to flux, which is apparently adding a carbon source. This is a bullet caster's trick. The guy who sold me the weights said to use candle wax. That is done after the first cleanup of clips, etc. Others recommend using saw dust as the source of carbon. I suspect the same stuff we use to thicken epoxy would work. Purpose is to kept the tin and antimony in suspension and to clean up the lead of impurities. Apparently, you can use quite a lot and it won't hurt anything. The more you use, the cleaner the lead gets. All bright, shiny and clean looking.
I also decided to order some special bentonite clay for green sand casting. Despite what you may read, cat litter won't work. The casting stuff is very, very fine microscopic powder. Have mixed some up and will experiment with it in coming days. First pour may test the pucker factor. Green sand is said to be porous enough to vent the steam to avoid any explosions. We will see. If this turns out to be my last posting, it didn't work.