Knowing how to make your own waterproof low-voltage connectors will come in handy when working on wiring exposed to the elements. They come in especially handy when working on low-voltage landscape lighting and automotive wiring. Making waterproof connections is crucial when working with low-voltage circuits because any current leakage to ground can cause serious problems. The connectors are easy to make using commonly available materials and tools that can be purchased at home centres and hardware stores.
Select a piece of heat shrink tubing slightly larger in diameter than the crimp-on connector that you are going to use to make the waterproof connector. Cut the heat shrink tubing one inch longer than the crimp-on connector. You will want the heat shrink tubing to extend at least ½ inch beyond the ends of the crimp-on connector.
Slip the section of heat shrink tubing over one of the wires to be spliced together. You make your own waterproof connector at the same time you make the waterproof connection; it is an all-in-one process. This is just one method for making do-it-yourself waterproof connectors, but it is the easiest method for the inexperienced do-it-yourself person to master.
Grasp one of the wires firmly in your left hand and strip 3/8 inches of insulation from its end. Grasp the remaining wire firmly in your left hand and strip 3/8 inches of insulation from its end.
Connect the two, stripped ends together using a crimp-on butt connector. Crimp-on connectors are colour coded by wire size. The three most common sizes are designated by Red, Blue and Yellow insulated sleeves. The Red connectors are designed for use with AWG 22 through AWG 18 stranded wire. The Blue connectors are designed for use with AWG 16 through AWG 14 stranded wire. The yellow connectors are designed for use with AWG 12 through AWG 10 stranded wire. Match the colour-coded jaws on the crimping tool with the colour of the connector.
Center the shrink tubing over the crimped connector. Plug in the hot air gun and apply the heat evenly along the full length of the heat shrink tubing. Use caution when using an industrial hot air gun—it is not a hair dryer. A hot air gun gets hot enough to peel skin from your fingers.