1 second is nowhere near long enough. Maybe 3 seconds on an old solder joint, the flux needs TIME to clean the metals especially the steel component lead. You need to get it wet, get some solder on, remove the dead solder and filth (tap the tip to flick it off in your tray) and once more with fresh solder for the final joint.
With a new clean PCB and component leg, especially a small pad size, 1 second may be enough but even then i'd say 1.5 seconds and two quick solder dabs.
For large joints like the heatsink tabs I get it wet then apply LOTS of excess solder, then just hold the side of the tip on it and wait. The increased thermal mass of that big melted solder blob and its increased contact area with both the tip and the PCB helps carry the heat into the PCB copper and the heatsink tab much quicker.
For removing parts like TO-220 (and all 3 leg transistors, even most 2 leg caps etc) I apply a heap of solder to all legs at once (again the thermal mass) and jam the side of the tip against all the legs at once. Generally you can remove a transistor in about 2 seconds this way and it's so quick you wont damage the PCB so it's not as butcherous as it sounds. I also like to run my iron tip a little hot at 325'C and get in and out quicker but it does require a bit more cleaning of the tip.
When we had TV repair shops I used to get the apprentices practicing for a few weeks desoldering parts from TV and VCR PCBs for at least a couple hours a day. When they can pull a cap or TO-220 in a couple of seconds, and a DIP 16 with a sucker in under a minute then they can solder pretty well.