Hi. I think I read somewhere that someone said that it was better to use the solid wire solder drag soldering rather than the flux cored kinds. There wasn't any explanation behind it, except that the flux should have already been added to the PCB separately in much larger amounts. I was just wondering if the flux core is needed to properly to properly wet the tip (or fill the hoof in the tip of the iron) before drag soldering. Like...the flux has to do something to the solder iron tip right? Remove oxidation or something? Or does it just shorten tip life?