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RangersSuck RangersSuck is offline
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Default Lamp Repair using a Rigger's Constricting Knot

On Wednesday, December 9, 2015 at 8:39:21 PM UTC-5, DoN. Nichols wrote:
On 2015-12-09, Larry Jaques wrote:
On Wed, 09 Dec 2015 10:14:48 -0500, Joseph Gwinn
wrote:

On Dec 8, 2015, Joe Gwinn wrote
(in article ):


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.


[ ... ]

Followup: It failed already - the constrictor knot just slid off the cable.
Probably due to the heat of the lamp softening things. I'll probably make
some kind of tight-fitting swage collar of metal.


Have you considered NOT hanging the lamp by the cord? It has always
seemed to be a short waiting to happen, as the knots slip out,
knocking off the poorly applied wire nuts...


Well ... there is the "Underwriter's Knot", which used to be
used to keep wires from pulling out of fixtures -- back before things
like the Heyco strain relief nuts replaced grommets. (And the knot did
not even require a special tool, unlike the Heyco strain relief nuts.

O.K. This site gives a video:

https://www.youtube.com/watch?v=KHRaRRWW34w

And this one is pure text:

http://www.howtodothings.com/home-garden/how-to-tie-an-underwriters-knot

Enjoy,
DoN.

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I wonder how many lamps are strain-relieved by underwriters knots. Tens of millions, perhaps? This was one of the first 'electrical' things I ever learned.

Meanwhile, I watched the video, which was perfect. Then I watched another about the 'truckers hitch.' That's a new one on me. I always use ratchet strap tiedowns, but I do like this knot.