Multistrand wire is more flexible and less heavy than solid core wire. It is used in power cords, lighting circuits and many electrical appliances where flexibility is important. The stranded nature of the wire is sometimes a disadvantage when connecting it to terminals. The flexibility of multistrand wire makes it challenging to solder unless the correct technique is used. Anyone with access to a soldering iron and resin-core solder can produce a good solder joint in multistrand wire by working methodically and with care.
Switch on the soldering iron and allow it to reach its operating temperature. If the iron requires tinning prior to use, melt a blob of solder on the tip and then wipe it off with a wet sponge. The tip of the iron is ready when a thin layer of solder covers it.
Strip away sufficient outer insulation from the wire. Twist the fine strands together between your fingers until they form a single rod of wire. If the wire looks dull or contaminated, clean it with fine sandpaper or a sharp knife until the surface is bright and free from dirt.
Heat the twisted wire for a few seconds with the tip of the soldering iron. Tin the wire by placing solder on the far side of the wire, not on the soldering iron. Allow the solder to flow into the wire, and then remove it from the heat. Allow the wire to cool naturally, retaining a shiny surface.
Solder the prepared multi-strand wire to another wire or component by first tinning and heating the other object until the solder melts. Place the wire on top of the heated solder, and then apply the soldering iron to the wire. When the solder in the wire melts remove the iron and allow the wire to cool.
Always clean the wire until it is shiny, and then solder it. Solder as quickly as possible to reduce damage to the insulation and nearby components.
Soldering irons may reach 400 degrees C. Avoid contact with skin and flammable materials. Molten solder produces poisonous lead fumes.