Multiple Connection Solder Techniques

Tools

• Wire strippers are essential to removing the outer insulation from a wire without damaging the conductor. Two types are available: mechanical and thermal. A temperature-controlled soldering iron with an appropriately sized tip is necessary. The tip should be large enough to transfer heat quickly to the solder joint. Use rosin flux and rosin core solder. Alcohol and cotton swabs will clean up any excess flux. Finally, use a sharp wire cutter and round-nose pliers to form wire loops.

Preparation

• To connect multiple stranded wires to a post terminal, begin by stripping about 10 to 12 mm of the insulation from each wire. Heat the soldering iron and use it to apply solder to the stripped ends. This is called "tinning," and it performs two functions by helping the wire retain its shape as it is formed and reducing the time heat is applied.

Forming the Wire

• Use the round-nose pliers to form small, U-shaped loops in the tinned ends. This will require some practice because in the finished joint, the insulation should have a gap between its end and the post terminal. Ideally, the gap should be the same width as the wire, so practice until you can form the wire correctly. Cut off any excess wire, but leave just enough to close the U around the terminal with the round-nose pliers. This is an excellent mechanical connection.

Soldering Single Wires

• There are two ways to solder multiple wires. The first is to solder each wire individually beginning at the bottom of the terminal. Apply rosin flux, then heat the joint with the soldering iron and flow solder into it. Use only enough solder to connect the two metal parts with a shiny, slightly concave fillet. Excess solder will get in the way of subsequent wires, so avoid applying too much. When the terminal is cool, attach the next wire and solder it.

Soldering Multiple Wires

• The second method of attaching multiple wires is to solder them all in one operation. Form and attach each wire in turn beginning at the bottom of the post terminal. When they are all in place, apply some flux. Use a large tip on the soldering iron, as this method requires a lot of heat. Bring the iron in contact with the bottom-most part of the joint and feed solder into it. Slide the iron up and solder the middle. Watch carefully to prevent applying too much solder. Slide the iron up again and solder the top.