ORIGINAL: Redback
To avoid overheating when soldering it is important that you use an iron that is large enough.
Whilst this sounds backwards, a large iron will get the area you want to solder up to temperature quickly. A smaller iron will take longer, and all the while the heat is conducting away from the joint to the surrounding area.
Terry
Good point.. i believe the one i use is 40 watts? i have a lil pencil and a gun type as well.