Sorry, I'll fight you very strongly on this. Most soldering that relies on effects from solder surface tension simply will not work without quite a bit more fl

Sorry, I'll fight you very strongly on this. Most soldering that relies on effects from solder surface tension simply will not work without quite a bit more flux than you can get from the core of a solder wire. Drag soldering, for example, won't work on quad flat pack chips without quite a bit of flux. And while my techs will absolutely back you up that my soldering skill sucks, to a person they ALL use solder flux for their soldering. Not even a single exception. And they're all trained to NASA aerospace standards. Now, maybe you can be more skilled than they are and get away without using solder; however, back down here in reality, the rest of us punters will just add flux when soldering stuff, thanks.