Nigel Goodwin : "...but why are you using extra flux?, and is it flux specifically designed for electronics use?"
The extra flux is both to prevent oxidation on the soldering iron tip and IC component leads, which is catalyzed during heating, and to improve the wetting of the solder so that the tip wicks the solder away from the joint, which is improved if the first purpose is simultaneously occurring, creating somewhat of a synergistic technique. And apparently, that flux type isn't compatible with electronics, according to a few of the replies.