An Electrical Question

[Mike Cutler]

No worries folks, I'm not looking for any "modern" code compliance questions. I just have a curiosity.

My house was built in 1919, and at one point in time had knob and tube installed. All of the tube holes, and I mean every one that I have uncovered, are drilled at an upward angle through the joists. It's nice work, and whomever did it either had a jig, or one very steady hand, because the angles are almost identical.
Why the angle? I'm guessing that it was to keep the original wiring semi taut as it transitioned joists.

[Ed Griner]

The holes were drilled by hand,with a brace and bit.You couldn't swing the brace,if you drilled flat.

Ed

[Mike Cutler]

The holes were drilled by hand,with a brace and bit.You couldn't swing the brace,if you drilled flat.

Ed

I like that answer. I hadn't considered that.
By hand, with a brace, that carpenter or electrician must have been very good.

Thanks Ed.

[Bill Brady]

They were drilled at an angle to keep the ceramic insulator in the hole.

[Rod Sheridan]

They were indeed drilled on an angle with a brace and bit, to keep the insulator in, and allow room for the brace.

My father, who was an electrician when knob and tube was being installed, used a standard brace and a joist brace which looked like a large ratchet. The joist brace was used where you couldn't fit a conventional brace.

I have a very old Black and Decker "3/8" Heavy Duty Drill" which eventually replaced the brace. It has a D handle, a side handle and a pipe handle, and looks like a modern 3/4" drill. I don't know if Dad purchased it in the 30's or after he came back from WW II.

I still have his Naptha torch and soldering iron that he used for splices and taps on the knob and tube system. A very high quality installation.

Regards, Rod.

[Mike Cutler]

Thanks for the answers folks. I think I now have a clearer understanding of the process.
Older houses are interesting, sometimes , the construction methods and materials are different than modern techniques. Of course, it also means that most of the construction materials at the local 'Borg are incorrect in dimension, and have to be custom cut, which is what got me back into wood working in the first place.

[John Neel]

I knew I had a few posts in my house, but yesterday I discovered one of the circuits is still live! I then discovered a bare wire splice. It is up between the joists and only about 4 inches of splice is showing, so there is little danger. I will check the angles when I repair the circuit tomorrow.

John Neel

[Duane McGuire]

They were indeed drilled on an angle with a brace and bit, to keep the insulator in, and allow room for the brace.

Fascinating! People here know so much! It's probably useless knowledge, but somehow I find it valuable to know. Thank you.

[Matt Edwards]

On a side note, the tubes which are a ceramic, make fantastic knife sharpeners for maintaining a really good edge.

Matt