Can anyone provide some soldering tips? I successfully soldered my two wires to one outer leg and the middle leg on my 1K variable resistor. I tinned the other ends of the wires in preparation for soldering to the card. I first tried to solder the ground wire to a solder pad. The solder will melt, but it just won't stick to the solder pad. I'm using a 15W soldering iron and 60/40 solder.