I normally flux my range scrap with sawdust two or more times before I pour it into ingots. When I cast boolits I melt my ingots and may add some tin. I flux this with sawdust and add about a teaspoon of beeswax. Stirring and then leaving the charred sawdust etc stay on the top to make a seal from the air.
I’ve come across others who use cat litter to cover the alloy when casting. Is there an advantage to using this method ? Do many others do it? Is there a better way than just leaving the old flux on top?
Thanks