How to Waterproof Coax Cables

By C.L. Rease

Sealing coax cables reduces corrosion.
i coaxial cable connection image by Michael Shake from

Coax cables transfer audio and video signals from a receiver to a piece of electrical equipment. Keeping moisture from entering exterior mounted coax cables eliminates corrosion on the coax connectors and reduces signal interference caused by internal corrosion on the cable. Moisture barriers geared toward sealing coax cable tend to breakdown when exposed to direct sunlight. Protecting the sealing barrier against UV light will increase the lifespan of the sealant.

Step 1

Wipe the coax cable and cable connections with a clean rag. Inspect the cable for abrasions or holes while you clean. Mark each defect with a paint marker.

Step 2

Cut a piece of rubber cable sealing tape 10 inches for each exterior cable connection long with a pair of scissors.

Step 3

Remove the paper backing from the sealing tape. Push one end of the sealing tape onto the cable approximately 2 inches back from the cable connection. Wrap the sealing tape toward the connection, overlapping the tape 1/4 to 1/2 inch with each wrap as you keep the tape pulled tight. Press the end of the tape to the cable on the other side of the cable connection.

Step 4

Wrap each connection as described. Seal each marked hole and abrasion with a length of tape that allows you to cover 3 inches of the cable surrounding the cable defect.

Step 5

Press electrical tape to the coax cable, 1/2 inch away from one of the areas containing rubber sealing tape. Tightly wrap the electrical tape over the sealing tape until you cover the connection plus an additional 1/2 inch. Wrap each sealing tape protected area with the electrical tape to protect the sealed connection from UV light.