Yesterday, I noticed that the lamp hanging over the kitchen sink was no longer hanging by the woven polyester cable sheath (which is intended to carry the weight of the lamp fixture) and was now hanging by the electrical wires. Which were coming undone - the terminal screws had already backed out a bit. Not good.
It turned out that over the five years since installation, the cable sheath had wiggled out of the crimped strain relief ring ferrule at the lamp end of the cable. The ring was crimped by being crushed into a (US) football shape, and one end had broken, reducing the clamping pressure on the cable. Discarded the ferrule. But what to replace it with?
In the thread on corrosion when aluminum and stainless steel are in contact, I had mentioned the Rigger's Apprentice book, and their recipes for lanolin as a corrosion preventer.
This same book talks of "constrictor knots", used to repair such things as split tillers. Hmm. This could work.
So, I replaced the metal ferrule with a double constrictor knot made of nylon cord, all well daubed with Pliobond rubber cement. We'll see how well this works, but it ought to be permanent.
Joe Gwinn
Ref: "The Complete Rigger's Apprentice - Tools and Techniques for Modern and Traditional Rigging", Brion Toss, International Marine, Camden, Maine, 1998 McGraw-Hill.