ECN Forum Forums General Topics of the Trade General Discussion Area Old Cloth-Covered Wire

... A customer told me of an interesting way of "doctoring" up old cloth covered wire..He said that some time ago,an electrician was working at his home and came across the cracked,frail,frayed wires in a box,and instead of just taping them up,used an ordinary drinking straw,which he simply covered over the offending,denuded wire,and some kind of polymer that had two parts,much like epoxy does,and a syringe-like applicator with which he "injected" the polymer into the straw,waited a few minutes,removed the straw,and ...voila,..a new pliable,flexible rubber/latex insulation covering for the wire...Has ANYONE here heard of such a thing?? The guy who told me this is a Dentist,and explained the process explicitly so I believe he wasn't making it up...I just never heard of this type of agent for this type of application... Help!!
Russ

Russ,
That's a rather interesting concept.
However, doing a thing like this would mean that you would have to make sure that the wire concerned was absolutely straight, to be in the middle of the insulation.
Personally, I'd replace any wire like that if the insulation was that bad on it, you don't know what the rest of it in the walls/attic is like.
Good idea though.

it was a dentist who gave you this idea? maybe he is making his crowns the same way? Look out for the root canal...

I expect that what the dentist really saw was the use of "cold" shrink tube, which has a liner removed to 'shrink' it.

How about a much simpler, faster, and cheaper method?

Simply slide a section of insulation stripped from a piece of one-size up (i.e., use new #12 insulation for old #14 wire) right over the stripped old wire. New insulation, and your choice of colors to boot.

After sliding the insulation as far as you can, trim the excess and strip a little bit less than usual, grip the tip of the wire with your Kleins, and push the insulation farther into the old sheath.

This will avoid a possible short where the old wires enter the box and pass through the cable clamp. Typically, only the stripped portion crumbles and falls off. There's no need to replace an entire run.

... Yeah, Larry,..I've done it that way,..seems to be the best/easiest way...If there's enough slack,I've even cut back on the old BX casing and found the wires to be in perfect condition,like the day they were made...1800 years ago,complete with the beeswax cloth wrapping..I'm gonna try shrink tubing next,as I run into this alot,and want to find an effective way of dealing with it..
Russ