Knob & Tube wiring

[jmellc]

Knob& Tube was the only permitted single family wiring method in the county where I served my apprenticeship in the 60s.

Where in the world was this town? I wasn't in the trade in the 60's but I was a child watching people build and remodel around town. They were using plastic NM cable for most all wiring I saw. We were sort of a back country town but not to that degree. I 1st started work in 1976 and we didn't use it then at all. Our house was built in 1954, wired with 2 wire cloth NM.

I don't have my code book handy, but my recollection is that existing knob/tube can still be used, but not extended. I am quoting a job for bringing a new feeder to k/t after a copper theft, but I'm urging customer to replace it. This is his ideal time to do it.

 

[macmikeman]

There is a hardware store a bit north of me that still sells the ceramic tubes. I didn't see any knobs there.

The tubes must have a longer shelf life.

Maybe they are recycled ones. The tubes come out really easy, the knobs are a son of a gun to remove, I just leave those where they are. Them things had beefy nails holding them in place.

 

[MichaelGP3]

This is off the original topic, but I'm wondering how old is BX? I worked in an apartment building once that was wired with BX (cloth insulation on the 2 conductors; no bond wire). It looked to be the original wiring, and the owner said the building was built in 1925.

 

[jmellc]

Maybe they are recycled ones. The tubes come out really easy, the knobs are a son of a gun to remove, I just leave those where they are. Them things had beefy nails holding them in place.

Could be new ones. We had an old hardware store in my town that had all types of horse drawn plows & parts for them. They'd been in business since early 20's and had some unsold stuff for all those years. I'm sure many old stores have a handful of tubes or knobs that were never sold, thus are still on the shelf til owner trashes them. Might even find an occasional roll of the wire or loom. I guess loom was on rolls, anyone know?

 

[jmellc]

This is off the original topic, but I'm wondering how old is BX? I worked in an apartment building once that was wired with BX (cloth insulation on the 2 conductors; no bond wire). It looked to be the original wiring, and the owner said the building was built in 1925.

20's to the 50's best I know. I've seen some with the bond wire, I think from early 60's not sure. I find that BX is often in the worst shape of any wiring. If I have to rework a piece and cut a few inches off, it nearly always cracks off some insulation. I tape it up well and handle it gently. That with the bond wire is usually some better, as it's not quite as old.

 

[jmellc]

Inspector cleared me to refeed K/T in my upcoming repair job. I tried to get customer to replace it, but he wants to keep it.

 

[danickstr]

Mobile Electric in Seattle has a roll of loom, which can be bought by the foot for repairs. Don't' know where it comes from, but it is newish.