9.2: Soldered Connections
A variety of joints are used to prepare wires for soldering. These include:
- Western Union splice
- tap joint
- twist joint
Western Union splice
This splice joins the ends of two wires inline (compared to the twist joint below). Strip the wires for a length of 2.5 to 8 cm (1" to 3 " ), as shown in Figure \(\PageIndex{1}\). Clean the wire, then twist the ends of the wire tightly together as shown.
Tap joint
The tap joint (Figure \(\PageIndex{2}\)) connects a stranded wire to an intermediate point along the length of a second wire. Wrap the wire at least six times.
Twist joint
The twist joint (Figure \(\PageIndex{3}\)) is used to join parallel wires, whereas the Western Union splice is used to connect wires that are in line. Strip the insulation, clean the wires, and twist them together tightly for a length of 2.5 cm (1 in.).
Tinning stranded wire
In a general sense, tinning is the process of applying a thin layer of solder to something and will be discussed in more detail in Learning Task 2. In the case of stranded wire, you should tin the stripped ends of the wire to prevent the strands from separating while bending or connecting. Use only enough solder to make the stripped portion of the wire solid. The strands of the wire should be visible through the solder. Avoid solder from wicking in a wire underneath
the insulation because it will make the wire solid and cause it to break more easily.