Variable Temp Soldering Iron

Not variable-temperature, but temperature-controlled. That is, you want an iron that actually has a temperature-sensing element in it. That way it is the same temperature all the time.

An iron without that attribute (EVEN if it is "variable") is too hot some of the time and too cold at other times. Paradoxically, BOTH situations will result in overheating the thing you're working on. If the iron is too hot, you'll overheat it immediately. If the iron is too cool, you'll overheat neighboring components while waiting for the solder to melt and flow (there will be too much time for heat to flow).

Thank you for the explanation. How do I know the temperature setting required to solder every component? Is there a rule of thumb or something?

The temperature should be slightly above the melting point of the solder you are using. The time/temperature profile of the part you are soldering is most important. You should check the specs of the parts your are using.

Al

You can get one for less than that. Here's one for $35