Whether to attach pigtails or for providing power injection, the need to make electrically conductive connections between wires is very important.  There are many ways to accomplish this objective, I'm going to share the methods that we have used; Soldering, Solder Shrink Sleeves, and Butt Crimp Shrink connectors.

Soldering

This method involves using a solder iron to melt solder into a wire connection.  This is the absolute best option for conductive integrity but it can be a time consuming and tedious (my opinion) process.  To make the connection waterproof application of shrink tubing is also required.

Solder Shrink Sleeves

This are a Great invention that combines low melt solder, a shrink tube and hot glue rings into a single solution to provide a waterproof solder connection.  We used hundreds of these when they first became available.  Recently we have experienced several connection failures and have determined that 99% of them were failed solder sleeve connections.  It appears that the sleeves permit too much movement and the connection breaks down over time.  We have replaced these connections with Butt Crimp Shrink connectors.  Refer to the diagram below for the components of this connector.

  Connection Process

1. Strip the ends of the wires to be connected.

2. Insert the wires into the sleeve, overlapping them in the middle.

3. Use a heat gun (or flame) to melt the solder.  There will be a visible flow when the solder melts.

4. Continue to heat to shrink the tubing and melt the glue rings.  Fully melting the glue rings is important for a waterproof connection.

Butt Crimp Shrink Connectors

These are a metal "butt" connectors with an integrated piece of waterproof shrink wrap. A  crimping tool is used to crimp the wires in the connector resulting in a very strong mechanical connection.  The reduced shrink tube adds to the strength of the connection resulting in limited movement in teh connection. I shoudl mention that these connectors are a little bit contoversial because there is no solder involved causing people to question the quality of the electrical conductivity.  I've read articles that provide equally convincing support for both sides of the argument.  We have been using them for several years and have found them to be extremely reliable.  Refer to the diagram below for the components of this connector.

  Connection Process

1. Strip the ends of the wires to be connected.

2. Insert the wires into the butt connector as far as they will go.  Note: There is an obstruction in the tube that will prevent them from reaching eachother in the middle.

3. Use the crimping tool to crimp the tube against the wire.  Note: You may want to perform the insert and crimp step for each wire separately.

4. Use a heat gun to reduce the shrink tubing.

Connector Sizes/Colors

Most connectors are designed for a specific wire size.  To make it easy to identify the right connector, they use an industry standard color coding for wire size as follows:

• Red - 22-18 Gauge Wire

• Blue - 16-14 Gauge Wire

• Yellow - 12-10 Gauge Wire.