"David Nebenzahl" wrote in message
s.com...
On 10/26/2009 11:02 AM Existential Angst spake thus:

wrote in message
...

On Mon, 26 Oct 2009 11:38:56 -0400, "Existential Angst"
wrote:

Of course, the wiring is old, cloth covered, but in BX, and
super-high quality. The wire seems to be nickel or silver
coated/tinned -- not just ends, but the whole wire. Curious as to
what the purpose of that coating is.

The wire appears to be only 14 ga, but still more than ample for 15 A,
AND each splice is wire nutted AND soldered!!

You answered your own question. They tinned the copper wire because
it usually was going to be soldered.

So you mean the whole spool/reel of wire was tinned before the
insulation was added, in anticipation of soldering?
To avoid the local application of flux?

One would still need to use flux (most likely rosin, as in rosin-core
solder), but the tinning would prevent corrosion to some extent, plus make
soldering easier.

At least that's my understanding ...

By the way, I'm glad you expressed your appreciation of this antiquated
wiring, which is often in much better condition than people give it credit
for.

It's funny, we started with copper, went to tinned copper, went back to
copper, slid further back to effing aluminum (goodgawd), learned from that
mistake and went back to copper again. Altho power companies use aluminum
in parts of their service -- and steel!

Also, there are different grades of copper, wire supposedly being
"electrical grade", which is among the higher grades, iiuc. Electrical
grade copper commands a substantially higher scrap value than copper pipe,
altho I don't know how a dealer would tell, if it were copper bar.

I wouldn't be surprised if wire is now a crappy grade of copper. Proly
could tell by comparing the resistance of an old 500 ft spool to a new
one -- if one could find an old spool.
--
EA





--
Found--the gene that causes belief in genetic determinism