https://imgur.com/a/5ueM3J4
Melted down a bunch of range scrap last week and all went well till the last batch. Felt like I was Endlessly skimming till I started running out of propane. Turned off the burner and gave it one more swipe before it cooled. That's the clean spot in the middle.
Taking a handheld torch to the surface would cause it to shrink and pull the surface layer that's the odd spots on the surface.
I fluxed it 4 times with wax, once I'm ready to deal with this again do I just keep fluxing & skimming?
The pot was quite full and the temp seemed low as it would take time for the surface to brown before the rainbow effects.
The bad: no thermometer.