Woody wrote: ↑Mon Dec 28, 2020 6:41 pm
I just don't flux. Stir and skim. Discard the scum. The amount of waste is so small, it ain't worth the worry. All fluxing does is to turn the small amount of lead oxide back into metalic lead. I have had the scum tested and it is the same alloy mix as the main melt. Do your research and you will find the same results.
Woody
I’m glad you mentioned the ‘scum’ that accumulates on the top of the melt. I’m pretty new to casting, and I’ve always wondered if I was doing something wrong by removing this burned-looking ‘scum’. This sets my mind at ease. Thnx!
Robert
Nope. Once the tin/lead alloy is melted, it is a true alloy and will not separate. I'm not the chemist, but I have talked to several and researched this. Antimony alloys are not alloys, they are a mechanical mix. The antimony forms a matrix not a alloy, and again fluxing just doesn't justify the mess.
Woody
Richard A. Wood
If you are surrounded. You are in a target rich environment.
One of the things that helps reduce lead oxidation when using saw dust as flux is to leave the residue (ash) on top the melt. It's the oxygen in the air at the surface that is causing the lead to oxidize. This method works best when using a bottom pour pot.