ok i jus picked up a 30 watt all purpose soldering gun along with some .032 diameter standard Rosin-core solder. i jus tried to solder some bars together and it sems as if the solder isnt sticking to the metal, like il get it attached to one bar, and when i try to bring it to the other bar to join them, the bead of solder resin jus slides off the metal. whats up with that? its kinda like tryin to paint on a wet surface, it jus bubbles up and runs. what am i doing wrong? what do i need to do?