The secret of good soldering is to use the right amount of heat. Too little heat will result in a cold solder joint; too much heat can seriously damage a component. The key factors in quality soldering are time and temperature. Generally, rapid heating is desired. If heat is applied too long, the flux may be consumed and surface oxidation can become a problem.
All soldering should be performed with a soldering iron rated at approximately 45 watts. The tip should be kept clean by brushing it frequently on a moist sponge. You may use an iron that plugs directly into a wall outlet, or for better temperature control, use a soldering station. Soldering stations usually have a variable temperature control, which lets you set the right amount of heat to be used.
For good heat conduction between the soldering iron and the joint, a small amount of solder should be applied to the tinned portion of the soldering-iron tip, and this surface should be applied to the backside of the terminal. The solder wire is then applied to the front side of the terminal, but is not brought into contact with the iron (See figure 1). When the solder melts into the terminal and wire, the joint is properly soldered. The reason the iron is placed on the backside and the solder wire to the front side is that solder travels toward heat. This procedure avoids a cold solder joint that could cause trouble in the future. It is a good idea for the inexperienced hobbyist to practice soldering with some scrap terminals and wire.
Good practice tips:
1. Apply enough solder so that every strand of wire is surrounded by solder.
2. Do not over tin the wire or solder may flow up under the wire’s insulation causing it become rigid, or you will end up with globs of solder on the terminal that will have to be removed.
