Oldiron2 mentioned in post #28 poor boy soldering flux can be made from pine sap:
I have a pine tree needs to redeem itself because it has ruined so many paint jobs!
So as Oldiron2 said, I went out to the old pine tree and harvested some sap:
At Carbon-Arc break time, I set up the DIY flux smelter - frying pan and torch:
I had a little trouble finding just the right container to pour the flux into.
The hot flux was skimmed and then poured through a special flux maker's filter -not to be confused with a common red shop rag- into a retail ready package:
Of course quality testing was in order.
Before - Strap is heated hot enough to melt bar solder, but the solder will not wick or tin:
After - With Oldiron2's Marvel Mystery Flux:
Just a touch of Oldiron2's Marvel Mystery Flux - Instant flow, tin, and bond.