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The basic fundamental of electronics soldering is to properly apply solder to create a conductive connection. Soldering correctly is done by applying the soldering tip to the joint, heating it and applying the solder to the hot joint to melt it into a flow.

Tinning the Soldering Iron
You must tin the tip of your soldering iron every time you are ready to use it. Tinning is done by melting solder directly on the tip of the soldering iron. It keeps the tip from oxidizing, which can impede the transfer of heat to the joint being soldered. Touch the solder to the soldering iron tip and coat it with enough solder to cover it. Wipe the tip on a wet sponge to remove excess solder and reveal a shiny, silvery soldering tip.

Soldering
Use the iron to heat the joint, touch the solder to the heated joint and the solder will flow evenly over it. Melting the solder by touching it to the iron instead of the joint will create a "cold solder," which means the solder will not make a proper connection, it will crack or break easily, and will cause an electronic malfunction. A cold solder will look dull and pitted. A good solder will have an even covering of shiny, silvery solder on the joint.

Electronics Soldering
Prepare the wire to be soldered by stripping the insulation off, twisting the wire ends and attaching heat sinks to protect the insulation from melting. To make soldering to a bracket easier, tin the ends of the wire by heating them with the iron and touching solder to them in a gentle sweeping motion until the wire is shiny and silvery.

When soldering electronic components, bend the leads to secure the piece, cut the leads, apply heat sinks to fragile components, solder the joint, and clean with alcohol and a brush. Do not overheat what you are soldering because it can damage electronic components or cause wire insulation to melt or circuits to detach from the board.

Tips
Clean the soldering tip on a wet sponge every time you put it back in the holder or pick it up to use to keep the oxidation off the tip.

Bad soldering can be removed using copper braid or a solder sucker. The copper braid is laid over the solder to be removed. As the iron heats the copper braid, it liquefies the solder, which is absorbed by the braid. A solder sucker pulls up the melted solder to remove it.