Knob & Tube Repair

Status
Not open for further replies.
Assumption: The two ends of the cut wire just touch each other, or are very close to touching.

Strip back the two ends of the original K&T conductor 2 - 3". Take a short length of the same gauge conductor and form a "western union splice" on each end of the original K&T pulling the now spliced conductor taut, and thus, forming a solid mechanical connection. Solder and tape.

I expect that the tape is listed.

It can be argued that a wirenut is a suitable "listed" "splicer", but I'd rather not hash that out.
 
I would splice the wires together using a butt splice that is crimped in place and cover with heat shrink tubing. (Not necessarily in that order!)
 
K & T may have still been around when I started, but I don't have any time on it. So, are the conductors generally stranded or generally solid? I thought they were solid.

carl
 
coulter said:
K & T may have still been around when I started, but I don't have any time on it. So, are the conductors generally stranded or generally solid? I thought they were solid.

carl
Click to expand...

I have never seen stranded, only solid
 
1793 said:
I have never seen stranded, only solid
Click to expand...

Yup. Same experience here. I still see a lot of K&T (depending upon the age of the dwelling). I've never seen an original installation of K&T with stranded.

Now, DIY additions have afforded a few stranded conductors. . . but that's another story altogether.

The K&T solid is coated with tin and is, in my estimation, not quite as soft as contemporary NM-B solid conductors.
 
al hildenbrand said:
The K&T solid is coated with tin and is, in my estimation, not quite as soft as contemporary NM-B solid conductors.
Click to expand...

When working with older K&T or even the old 2 conductor cabling I often wonder why it has the grayish finish. I was under the impression it was copper clad, but you have solved the mystery for me.

What was the purpose of tin coating?
 
jes25 said:
What was the purpose of tin coating?
Click to expand...
The main use of the tin is to isolate the copper from the natural rubber/synthetic rubber insulation. The copper is chemically affected by contact with the rubber.
 
Sorry about the "listed tape" comment. . .I didn't mean to mislead. It was a backhanded comment to the point that the tape covering the splice was probably the only part of the splice that has a listing.

I keep at least a roll of rubber splice tape like a Scotch 23 on the truck. After rounding off any sharp corners or edges with the 23, covering the splice with a skin of plain old 33+ yields, IMO, a good looking finish.
 
tshea said:
I would splice the wires together using a butt splice that is crimped in place and cover with heat shrink tubing. (Not necessarily in that order!)
Click to expand...

When you put the heat shrink on first, how do you make the splice? :p :p :p
 
dlhoule said:
tshea said:
I would splice the wires together using a butt splice that is crimped in place and cover with heat shrink tubing. (Not necessarily in that order!)
Click to expand...

When you put the heat shrink on first, how do you make the splice? :p :p :p
Click to expand...

Very carefully!!!

(Not necessarily in that order!) :lol: :lol: :lol:
 
Status
Not open for further replies.
Top