How To Repair Frayed Cable Casing
In the relentless pursuit to make sound equipment for theatre smaller and less discernible to the audience, lavaliere microphones have become increasingly delicate. After the wear and tear of multiple performances, a common condition to arise is a split or shredded wire casing on an otherwise completely useful and expensive lavaliere microphone. As long as the internal wiring is still intact, there are couple options available to quickly repair the casing and get the mic back into the show rotation. We will discuss the cons of some conventional repair methods, and then I'll suggest an alternative repair method that effectively resolves some of these issues.
As a note, while this article is based on my experience as a theatrical audio engineer, this method will also work on Mac or iPhone charging cables, or any common rubber coated cable with damaged casing.
Problems with Conventional Repair Methods
Here are a few conventional repairs to the cable casing, all which have issues with durability or and/or feasibility for use in the unique setting of a theatrical performance:
Tape: While tape is the quickest way to repair cable casing, it is undoubtedly a temporary fix. Over a short period of time, either from continuous bending or sweat, the adhesive material on tape starts to give way, exposing the wiring to to further twisting and moisture damage.
Shrink Tubing: Shrink tubing can effectively immobilize the weakened point in the cable, but the result is typically about an inch long section of inflexible material that cannot conform with the movement of the cable. It can also be difficult to fit the appropriate size shrink tubing if neither end of the cable is stripped down to bare wire. Air gaps again leave room for twisting and moisture.
Putty: Newer Hardening putty options like Sugru can protect weak areas while remaining flexible, but the final repair is bulky. It is most commonly used the repair near a connector, but would not be ideal for repairing damage in the middle of the cable.
So how can we still repair the cable while avoiding some of the conventional issues? One solution is to use a product called flexible rubber coating. Flexible rubber coating is durable, flexible, paintable, waterproof, and cost effective. And it's readily available online or at any major hardware supplier.
How to Repair Cables Using Flexible Rubber Coating
Buy a spray can of Rust-Oleum LeakSeal Flexible Rubber Coating, available online or from your local hardware store. There are other products available like Plasti-dip it Flexi-dip, but these products are designed to be removable, so avoid using them. Buy Rust-Oleum LeakSeal
Prep the cable by cutting off any excess cable casing that does not lay flat against the internal wires. This will prevent bulging in the finalized repair.
Use a piece of cardboard or scrap paper and spray the rubberized material onto it in a small spot until you have about an 1/8″ of accumulation.
Roll the cable in the material until you have even and complete coverage over the damaged area. If there is only minor damage, you can spray directly onto the cable and still get acceptable coverage.
Leave the cable to dry overnight, preferably by suspending it away from any surface.
The final product should appear milky but translucent, and should be completely surrounding the damaged area.