Some insulated multistrnd copper wire is pre-tinned and a lot is
not.

What is the purpose of pre-tinned wire? As far as I can see the
advantage is that the copper core doesn't oxidise which means the
wire can be soldered or fixed to a terminate with only minimal
cleaning.

Sounds like a good thing to me, so why isn't almost all wire pre-
tinned?

Is cost really so different?

Does the tinning-coating replace where copper would have been in
the overall wire and tinning is of higher reistence?

Is flexibility affected?

On Fri, 17 Apr 2009 04:14:40 +0100, Sandi wrote:

:Some insulated multistrnd copper wire is pre-tinned and a lot is
:not.
:
:What is the purpose of pre-tinned wire? As far as I can see the
:advantage is that the copper core doesn't oxidise which means the
:wire can be soldered or fixed to a terminate with only minimal
:cleaning.
:
:Sounds like a good thing to me, so why isn't almost all wire pre-
:tinned?
:
:Is cost really so different?
:
oes the tinning-coating replace where copper would have been in
:the overall wire and tinning is of higher reistence?
:
:Is flexibility affected?


As you surmised, the answer is cost. It is not the cost of the tin itself but
the additional process and handling which adds to the complexity of production.
The copper conductor wire gauge is not made smaller where tinning is not applied
and the added few microns of tin would not affect resistance/unit length by any
significant degree. Flexibility is not an issue.

I think that manufacturers realise the majority of termination methods used
today rely on crimping or soldering while the copper conductors are clean.
Tinned conductors are an advantage where the conductors are secured by screws or
wire-wrap although less so for the latter. Insulation displacement techniques
are not a problem for untinned conductors.

Sandi wrote:
On 17 Apr 04:49, Ross Herbert wrote:

On Fri, 17 Apr 2009 04:14:40 +0100, Sandi
wrote:

:Some insulated multistrnd copper wire is pre-tinned and a lot
:is not.
:
:What is the purpose of pre-tinned wire? As far as I can see
:the advantage is that the copper core doesn't oxidise which
:means the wire can be soldered or fixed to a terminate with
nly minimal cleaning.
:
:Sounds like a good thing to me, so why isn't almost all wire
re- tinned?
:
:Is cost really so different?
:
oes the tinning-coating replace where copper would have been
:in the overall wire and tinning is of higher reistence?
:
:Is flexibility affected?


As you surmised, the answer is cost. It is not the cost of the
tin itself but the additional process and handling which adds
to the complexity of production. The copper conductor wire
gauge is not made smaller where tinning is not applied and the
added few microns of tin would not affect resistance/unit
length by any significant degree. Flexibility is not an issue.

I think that manufacturers realise the majority of termination
methods used today rely on crimping or soldering while the
copper conductors are clean. Tinned conductors are an
advantage where the conductors are secured by screws or
wire-wrap although less so for the latter. Insulation
displacement techniques are not a problem for untinned
conductors.

Is it real "tin" that's used?


No, it is usually tin/lead alloy, better known as solder.

Cheers

ian

On 4/17/2009 7:20 AM Ian Bell spake thus:

Sandi wrote:

Is it real "tin" that's used?

No, it is usually tin/lead alloy, better known as solder.

Not any more (post-RoHS). (Solder, yes, but not lead.)


--
Save the Planet
Kill Yourself

- motto of the Church of Euthanasia (http://www.churchofeuthanasia.org/)

David Nebenzahl wrote:
On 4/17/2009 7:20 AM Ian Bell spake thus:

Sandi wrote:

Is it real "tin" that's used?

No, it is usually tin/lead alloy, better known as solder.

Not any more (post-RoHS). (Solder, yes, but not lead.)




Fortunately I stocked up on the real stuff before they banned it ;-)

Cheers

Ian

On Fri, 17 Apr 2009 20:30:49 +0100, Ian Bell
wrote:

David Nebenzahl wrote:
On 4/17/2009 7:20 AM Ian Bell spake thus:

Sandi wrote:

Is it real "tin" that's used?

No, it is usually tin/lead alloy, better known as solder.

Not any more (post-RoHS). (Solder, yes, but not lead.)




Fortunately I stocked up on the real stuff before they banned it ;-)

Cheers

Ian


Sorry, but TPC wire was already RoHS compliant. All the idiots had to
do is change the label. TIN is TIN. It doesn't say "SPC" (Solder PLated
Wire)... It SAYS TPC TIN Plated Wire. Pretty simple.

SPC (Silver, of course) is better anyway... particularly from a shelf
life POV.

I hate TPC wire that has been around too long. The crap won't even
take solder. Give me SPC any day. The cost difference is negligible, if
one weighs the added labor cost of dealing with poor quality TPC, which
nearly all of it is.

On Fri, 17 Apr 2009 15:20:00 +0100, Ian Bell
wrote:

Sandi wrote:
On 17 Apr 04:49, Ross Herbert wrote:

On Fri, 17 Apr 2009 04:14:40 +0100, Sandi
wrote:

:Some insulated multistrnd copper wire is pre-tinned and a lot
:is not.
:
:What is the purpose of pre-tinned wire? As far as I can see
:the advantage is that the copper core doesn't oxidise which
:means the wire can be soldered or fixed to a terminate with
nly minimal cleaning.
:
:Sounds like a good thing to me, so why isn't almost all wire
re- tinned?
:
:Is cost really so different?
:
oes the tinning-coating replace where copper would have been
:in the overall wire and tinning is of higher reistence?
:
:Is flexibility affected?


As you surmised, the answer is cost. It is not the cost of the
tin itself but the additional process and handling which adds
to the complexity of production. The copper conductor wire
gauge is not made smaller where tinning is not applied and the
added few microns of tin would not affect resistance/unit
length by any significant degree. Flexibility is not an issue.

I think that manufacturers realise the majority of termination
methods used today rely on crimping or soldering while the
copper conductors are clean. Tinned conductors are an
advantage where the conductors are secured by screws or
wire-wrap although less so for the latter. Insulation
displacement techniques are not a problem for untinned
conductors.

Is it real "tin" that's used?


No, it is usually tin/lead alloy, better known as solder.

Cheers

ian


Folks in this discussion need to define "pre-tinned".

There is TPC wire, which is individual TIN plated Copper strands made
into mutli-stranded wire in the same process as any other stranded wire.

There is SPC, which is individual Silver plated Copper strands.

It was always my understanding that "pre-tinned" wire was stranded wire
that was run through a solder bath and tinned similarly as the 'tinning'
one would give the end of a wire in a solder pot.

If the wire is this type, it is used in certain industries to reduce
production labor costs. It is specifically NOT used in certain other
industries due to the problems associated with cinched type termination
processes and an effect known as 'solder creep'.

TPC is TIN plated, not solder plated. Just like it states.

"Pre-tinned wire" IS processed using solder.

"Sandi" wrote in message
...
snip
Does the tinning-coating replace where copper would have been in
the overall wire and tinning is of higher reistence?
Is flexibility affected?


Tin has a much lower conductivity than copper, and as RF travels on
the surface of a conductor, it would attenuate RF and high frequency AC

Steve Terry

Steve Terry wrote:

"Sandi" wrote in message

snip
Does the tinning-coating replace where copper would have been in
the overall wire and tinning is of higher reistence?
Is flexibility affected?

Tin has a much lower conductivity than copper, and as RF travels on
the surface of a conductor, it would attenuate RF and high frequency AC

Largely irrelevant since the RF flows on the surface of the entire bundle
of conductors, not individual uninsulated strands.

Graham

In article ,
"Steve Terry" wrote:

"Sandi" wrote in message
...
snip
Does the tinning-coating replace where copper would have been in
the overall wire and tinning is of higher reistence?
Is flexibility affected?


Tin has a much lower conductivity than copper, and as RF travels on
the surface of a conductor, it would attenuate RF and high frequency AC

Steve Terry

Is that why most, but not all, teflon insulated wire was silver plated?

Chuck P.

"Pilgrim"
"Steve Terry"
"Sandi"

Tin has a much lower conductivity than copper, and as RF travels on
the surface of a conductor, it would attenuate RF and high frequency AC


Is that why most, but not all, teflon insulated wire was silver plated?


** No.

Teflon coated wire intended is for high temp applications.

Silver has a much higher melting point than tin ( just a tad below copper)
and is more corrosion resistant too.



...... Phil

On Fri, 17 Apr 2009 22:35:39 +1000, "Phil Allison"
wrote:


"Pilgrim"
"Steve Terry"
"Sandi"

Tin has a much lower conductivity than copper, and as RF travels on
the surface of a conductor, it would attenuate RF and high frequency AC


Is that why most, but not all, teflon insulated wire was silver plated?


** No.

Teflon coated wire intended is for high temp applications.

With the sole exclusion of anything related to a nuclear reactor.

Teflon turns to powder in that environment, and they (Genral Atomics)do
not use it in such settings. You will see it used on the Predator,
however.

Silver has a much higher melting point than tin ( just a tad below copper)
and is more corrosion resistant too.

Also, purified Silver Oxide, made in the lab, conducts better than the
element itself does. Silver oxide on wires, and other conductive
surfaces creates a protective 'patina' on the surfaces that are exposed
to the air. In wiring, it does not affect the overall conductivity of
the wire. In the lab, it is the top dog.

Most conductive element: Silver

Most conductive compound: Silver Oxide






..... Phil

"Mr. Haney"
"Phil Allison"

** No.

Teflon coated wire intended is for high temp applications.

With the sole exclusion of anything related to a nuclear reactor.


** Wot utterly irrelevant drivel.


Silver has a much higher melting point than tin ( just a tad below copper)
and is more corrosion resistant too.

Also, purified Silver Oxide, made in the lab, conducts better than the
element itself does.


** Shame it does not even exist on silver objects or wires.


Silver oxide on wires, and other conductive
surfaces creates a protective 'patina' on the surfaces that are exposed
to the air.


** Absolute ******** !!!!!!!!!!!!!

The dark tarnish seen on silver is silver sulphide ( Ag2S ) - which is an
insulator.

Hanley is just parroting one of the DUMBEST MYTHS floating around the
internet and swallowed whole by audiophools.



...... Phil

In article , Pilgrim wrote:
In article ,
"Steve Terry" wrote:

"Sandi" wrote in message
...
snip
Does the tinning-coating replace where copper would have been in
the overall wire and tinning is of higher reistence?
Is flexibility affected?


Tin has a much lower conductivity than copper, and as RF travels on
the surface of a conductor, it would attenuate RF and high frequency AC

Steve Terry

Is that why most, but not all, teflon insulated wire was silver plated?

Chuck P.

Most of my TFE coated wire is not silvered butl is tinned. All TFE wirewrap is
silvered.

greg

On Apr 17, 8:41*am, Pilgrim wrote:
In article ,
*"Steve Terry" wrote:

"Sandi" wrote in message
...
snip
Does the tinning-coating replace where copper would have been in
the overall wire and tinning is of higher reistence?
Is flexibility affected?

Tin has a much lower conductivity than copper, and as RF travels on
the surface of a conductor, it would attenuate RF and high frequency AC

Steve Terry

Is that why most, but not all, teflon insulated wire was silver plated?

I think the reason for silver-plated teflon wiring is mostly milspec
compliance (and the follow-ons that include the mispecs.) The real
question is, why is it in the milspec? Certainly WWII and Korea
influenced milspecs a lot to focus on fungus-proofing, and Teflon had
some advantages back then when the other insulators were not so fungus
resistant. At the same time, other insulating materials can turn
copper or even tin-plated copper inside the insulation black with a
kinda sooty residue (common on Romex from the 50's-70's for example).
It seems to me that silver-plated teflon was a kind of knee jerk
reaction to these two issues, a belt-and-suspenders-cost-is-no-object
approach to a pretty mundane but really fundamental issue.

It's a real joy to work on ex-military equipment with Teflon cable
assemblies. Compare it to other consumer or less-speced industrial
stuff from the same era with PVC-type insulation, where you flex the
cable a little bit and the insulation cracks and falls off leaving
bare wires.

Tim N3QE

"Pilgrim" wrote in message
news
In article ,
"Steve Terry" wrote:

"Sandi" wrote in message
...
snip
Does the tinning-coating replace where copper would have been in
the overall wire and tinning is of higher reistence?
Is flexibility affected?


Tin has a much lower conductivity than copper, and as RF travels on
the surface of a conductor, it would attenuate RF and high frequency AC
Steve Terry

Is that why most, but not all, teflon insulated wire was silver plated?
Chuck P.

Yes, Silver is one of the few metals that has a lower resistance than
copper,
but oxidises easily so silver should be covered, PTFE is one of the best
coverings.

Steve Terry

On Fri, 17 Apr 2009 15:18:30 +0100, "Steve Terry"
wrote:


"Pilgrim" wrote in message
news
In article ,
"Steve Terry" wrote:

"Sandi" wrote in message
...
snip
Does the tinning-coating replace where copper would have been in
the overall wire and tinning is of higher reistence?
Is flexibility affected?


Tin has a much lower conductivity than copper, and as RF travels on
the surface of a conductor, it would attenuate RF and high frequency AC
Steve Terry

Is that why most, but not all, teflon insulated wire was silver plated?
Chuck P.

Yes, Silver is one of the few metals that has a lower resistance than
copper,
but oxidises easily so silver should be covered, PTFE is one of the best
coverings.

Steve Terry


Some of the newer wires have PTFE-Polyimide-PTFE insulation. Best of
both worlds.

On Apr 17, 7:18*am, "Steve Terry" wrote:
"Pilgrim" wrote in message

news


In article ,
"Steve Terry" wrote:

"Sandi" wrote in message
.. .
snip
Does the tinning-coating replace where copper would have been in
the overall wire and tinning is of higher reistence?
Is flexibility affected?

Tin has a much lower conductivity than copper, and as RF travels on
the surface of a conductor, it would attenuate RF and high frequency AC
Steve Terry

Is that why most, but not all, teflon insulated wire was silver plated?
Chuck P.

Yes, Silver is one of the few metals that has a lower resistance than
copper,
but oxidises easily so silver should be covered, PTFE is one of the best
coverings.


Silver does not oxidize so much as it tarnishes, by picking up sulfur
from the air.

Silver does not oxidize so much as it tarnishes,
by picking up sulfur from the air.

Same thing. Chemically, it's oxidation. Silver cleaners/polishes are
reducing agents (eg, Tarn-X).

On Fri, 17 Apr 2009 17:30:45 -0700 (PDT), wrote:

On Apr 17, 7:18*am, "Steve Terry" wrote:
"Pilgrim" wrote in message

news


In article ,
"Steve Terry" wrote:

"Sandi" wrote in message
.. .
snip
Does the tinning-coating replace where copper would have been in
the overall wire and tinning is of higher reistence?
Is flexibility affected?

Tin has a much lower conductivity than copper, and as RF travels on
the surface of a conductor, it would attenuate RF and high frequency AC
Steve Terry

Is that why most, but not all, teflon insulated wire was silver plated?
Chuck P.

Yes, Silver is one of the few metals that has a lower resistance than
copper,
but oxidises easily so silver should be covered, PTFE is one of the best
coverings.


Silver does not oxidize so much as it tarnishes,

Tarnish IS oxide, you dope. Silver oxidizes, it just doesn't grow a
crust like Copper does, regardless of whatever other elements it grabs
while doing it.

by picking up sulfur
from the air.

You are thinking of Copper.

On Fri, 17 Apr 2009 17:30:45 -0700, spamtrap1888 wrote:

Silver does not oxidize so much as it tarnishes, by picking up sulfur from
the air.

I once watched a guy build a 1KW linear out of surplus parts. He had this
beautiful silver-plated tank coil, and this idiot SAMDPAPERED the tarnish
off!

Can you say "skin effect", boys and girls? ;-)

Cheers!
Rich

On Fri, 17 Apr 2009 15:18:30 +0100, "Steve Terry"
wrote:

but oxidises easily so silver should be covered, PTFE is one of the best
coverings.


Silver oxide is acceptable. It remains as a mechanical part of the
surface, and does not adversely affect conductivity.

Copper oxide is an unacceptable CRUST on your wire.

That is one reason why Sivler was used to plate copper wires.

"Mr. Haney the Dickwad "


Silver oxide is acceptable.

** But non existent on wires etc.

It remains as a mechanical part of the
surface, and does not adversely affect conductivity.


** Since it does not exist on wire surfaces, that is true.

Hanley is a TOTAL MORON !!!




....... Phil

In article
,
Pilgrim wrote:

Is that why most, but not all, teflon insulated wire was silver plated?

My guess is that tinned wire is soldered more easily even after much
exposure to unfriendly environments. You do not have any copper oxide to
remove. Any crap in the tin flots away and new solder flows in under
such crap.

Bill

--
Private Profit; Public Poop! Avoid collateral windfall!

On 17 Apr 16:22, Salmon Egg wrote:

In article
,
Pilgrim wrote:

Is that why most, but not all, teflon insulated wire was
silver plated?

My guess is that tinned wire is soldered more easily even
after much exposure to unfriendly environments. You do not
have any copper oxide to remove. Any crap in the tin flots
away and new solder flows in under such crap.


That's what I would have thought too. But if pre-tinned (plastic
insulated) wire is so useful in this respect then why isn't pre-
tinned found more often?

I'm not thinking of the use of wire at RF frequencies but as an
interconecting wire.

I haven't managed to compare the cost of pre-tinned wire identical
plain copper wire but I don't ever recall seeing tinned wire and
thinking it was unexpectedly expensive. Has anyone got any info
from making this comparison in the past?

This thread has gone on along time without seeming to go anywhere. In a
hope to end it and move on, I did a Google search. My best immediate hit
was: http://www.cardinalproaudio.com/main/instrume.htm,

It gave my reason first--it is easier to solder. The second one was also
commonly posted. The tin protects against copper getting oxidized if it
sits on the shelf for a long time.

What this site did not say was that the coating is not actually tin. But
I as well as many other posters use the term tin instead of solder.

Can we move on now?

Bill

--
Private Profit; Public Poop! Avoid collateral windfall!

On Wed, 22 Apr 2009 18:39:16 -0700, Salmon Egg
wrote:

This thread has gone on along time without seeming to go anywhere. In a
hope to end it and move on, I did a Google search. My best immediate hit
was: http://www.cardinalproaudio.com/main/instrume.htm,

It gave my reason first--it is easier to solder. The second one was also
commonly posted. The tin protects against copper getting oxidized if it
sits on the shelf for a long time.

What this site did not say was that the coating is not actually tin. But
I as well as many other posters use the term tin instead of solder.

Can we move on now?

Bill


Tinning, in soldering nomenclature refers to dipping the stripped ends
of a stranded wire into a solder pot after applying flux to it.
"Pre-tinned wire" is a stranded wire where the entire length of the wire
has been "tinned" (read solder impregnated) during manufacture, before
the sheath (insulation) is added.

It is entirely different than TPC, which IS TIN plated copper wire.

Pre-tinned wire is made for manufacturing processes where labor costs
have been pared down. It has nothing to do with shelf life other than
how it relates to manufacturers and THEIR shelf life during a production
cycle. It would oxidize at the same rate that a solder joint does, which
is near NONE.

I doubt seriously that you will ever find RoHS "pre-tinned wire"
anywhere as it is likely a very poor wire being tinned with RoHS solders.

PVC wire is more porous than tfe is, so it will allow oxygen to attack
the wire, even though it is sheathed. TFE allows NO oxygen into the wire
via the sheath, so it has a long shelf life regardless of the wire type
inside.

So, TPC and SPC are true plated wire assemblies, and "pre-tinned wire"
is a cheap way for a manufacturer to cut costs and give a cheaper product
as well.

Pre-tinned wire is MORE susceptible to fracture due to flexing of the
wire as it is actually a single strand as a result of the way it is made.
TPC and SPC are true stranded designs and allow flexure without work
hardening the copper inside.

Essentially pre-tinned wire sucks and is a lame choice for ANYONE
trying to build a nice piece of equipment. The difference in cost is not
enough to say that economizing by using it yields any benefit other than
to expose the designer as a cheap, stupid *******, at best.

In article ,
Pilgrim wrote:

Tin has a much lower conductivity than copper, and as RF travels on
the surface of a conductor, it would attenuate RF and high frequency AC

Is that why most, but not all, teflon insulated wire was silver plated?

My understanding is that the Teflon-insulated wire uses silverplating
for a couple of reasons, related to the high melting point of Teflon
(and thus the high temperatures to which the wire is exposed when the
Teflon is melt-extruded onto the conductors).

The old-standard tin/lead tinning material can't be used in this
high-temperature environment, as it would be melted by the heat of the
Teflon extrusion, and would fuse a stranded-conductor wire into an
inflexible single strand.

Not tinning or plating the wire would leave the surface of the copper
exposed to high temperatures during the extrusion... I suspect that it
would oxidize (if there's any free oxygen in that environment... dunno
about that) or might react with the polymer. Even if it didn't react
at that time, oxygen would infiltrate the wire at the cut end (albeit
slowly) and the last few inches of the wire might end up with a
significant amount of copper oxide on the conducter surface.

Silver-plating protects the copper from oxidation (I gather that
silver oxide is somewhat easier for fluxes to deal with?) and the
silver doesn't melt at the Teflon extrusion temperature.

I don't believe that the silver plating is thick enough to give the
wire a significant conductivity advantage over pure copper, even at RF
frequencies.

--
Dave Platt AE6EO
Friends of Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!

In article , (Dave Platt) wrote:
In article ,
Pilgrim wrote:

Tin has a much lower conductivity than copper, and as RF travels on
the surface of a conductor, it would attenuate RF and high frequency AC

Is that why most, but not all, teflon insulated wire was silver plated?

My understanding is that the Teflon-insulated wire uses silverplating
for a couple of reasons, related to the high melting point of Teflon
(and thus the high temperatures to which the wire is exposed when the
Teflon is melt-extruded onto the conductors).

I checked looked at a spool of about #20 stranded wire. It does look very shiny like silver.
I thought it was odd looking at it. its made up of a tightly twisted center
section and a loosly woven outer section around the inner section. The TFE is
almost a fluorescent blue. Neat stuff. 19/32 strands.

In article , (GregS) wrote:
In article , (Dave Platt)
wrote:
In article ,
Pilgrim wrote:

Tin has a much lower conductivity than copper, and as RF travels on
the surface of a conductor, it would attenuate RF and high frequency AC

Is that why most, but not all, teflon insulated wire was silver plated?

My understanding is that the Teflon-insulated wire uses silverplating
for a couple of reasons, related to the high melting point of Teflon
(and thus the high temperatures to which the wire is exposed when the
Teflon is melt-extruded onto the conductors).

I checked looked at a spool of about #20 stranded wire. It does look very shiny
like silver.
I thought it was odd looking at it. its made up of a tightly twisted center
section and a loosly woven outer section around the inner section. The TFE is
almost a fluorescent blue. Neat stuff. 19/32 strands.


This got to be audio grade !

On Fri, 17 Apr 2009 11:29:51 -0700, (Dave Platt)
wrote:

I don't believe that the silver plating is thick enough to give the
wire a significant conductivity advantage over pure copper, even at RF
frequencies.


There are grades of plating, just like there are grades of say hard
anodizing surface thickness for Aluminum, which affects its insulative
capacity (electrical).

On Fri, 17 Apr 2009 05:41:50 -0700, Pilgrim wrote:

In article ,
"Steve Terry" wrote:

"Sandi" wrote in message
...
snip
Does the tinning-coating replace where copper would have been in
the overall wire and tinning is of higher reistence?
Is flexibility affected?


Tin has a much lower conductivity than copper, and as RF travels on
the surface of a conductor, it would attenuate RF and high frequency AC

Steve Terry

Is that why most, but not all, teflon insulated wire was silver plated?

Chuck P.


Wrong. The customer gets what the customer buys. If all YOU were
exposed to was SPC TFE, the THAT was ALL your employer was buying, you
dope. TPC was just as prevalent, despite the fact that it sucks on so
many levels.

On Fri, 17 Apr 2009 10:07:46 +0100, "Steve Terry"
wrote:


"Sandi" wrote in message
...
snip
Does the tinning-coating replace where copper would have been in
the overall wire and tinning is of higher reistence?
Is flexibility affected?


Tin has a much lower conductivity than copper, and as RF travels on
the surface of a conductor, it would attenuate RF and high frequency AC

Steve Terry


That's why one should use SPC, which is Silver plated Copper.

Sandi wrote:

Some insulated multistrnd copper wire is pre-tinned and a lot is
not.

What is the purpose of pre-tinned wire? As far as I can see the
advantage is that the copper core doesn't oxidise which means the
wire can be soldered or fixed to a terminate with only minimal
cleaning.

Sounds like a good thing to me, so why isn't almost all wire pre-
tinned?

Is cost really so different?

Does the tinning-coating replace where copper would have been in
the overall wire and tinning is of higher reistence?

Is flexibility affected?

Are you certain that its tinned wire you are looking at and not
nickel-plated copper? That is often used for high temp applications
where the copper alone will oxidize.

--
Paul Hovnanian
------------------------------------------------------------------
At some point it becomes necessary to behead all the architects and
begin construction. -- Abi-Bar-Shim (Project Mgr. - Great Pyramid)

On Fri, 17 Apr 2009 04:14:40 +0100, Sandi wrote:

Some insulated multistrnd copper wire is pre-tinned and a lot is not.

What is the purpose of pre-tinned wire? As far as I can see the advantage
is that the copper core doesn't oxidise which means the wire can be
soldered or fixed to a terminate with only minimal cleaning.

Sounds like a good thing to me, so why isn't almost all wire pre- tinned?

Is cost really so different?

Does the tinning-coating replace where copper would have been in the
overall wire and tinning is of higher reistence?

Is flexibility affected?

The best I can remember was that the original plastic coating first used
when the cloth covering was abandoned was somewhat corrosive adding to the
problems of exposure to other corrosive elements including poor annealing
of the core wires and would usually result in you having to scrape the
wire ends before trying to solder them since the wire was usually oxidized
enough to interfere with proper solder adhesion off the spool new.

Tinning did away with this aggravation and the need to use corrosive flux
to get a proper solder joint. Though some of the early tinning was poor
quality and corroded also.

Early tinned wire was slightly stiffer and a tinned stranded conductor was
almost as stiff as a solid wire. with thinner plating techniques this is
not the case any more except for much of the wire made in the far east.

This was usually offset by going to a smaller gauge wire.

Most early primary electronic wiring was originally something between 14
and 16 ga. with tinned wires this became 18 to 20 ga. in most cases.

Gnack

On Apr 16, 11:14*pm, Sandi wrote:
Some insulated multistrnd copper wire is pre-tinned and a lot is
not.

What is the purpose of pre-tinned wire? As far as I can see the
advantage is that the copper core doesn't oxidise which means the
wire can be soldered or fixed to a terminate with only minimal *
cleaning.

Sounds like a good thing to me, so why isn't almost all wire pre-
tinned?

Is cost really so different? *

Does the tinning-coating replace where copper would have been in
the overall wire and tinning is of higher reistence?

Is flexibility affected?

ALL I CAN THINK OF BESIDES THE FACT THAT WIRE ONLY INTENDED FOR
SOLDERING SHOULD BE TINNED IS THAT IT IS DEEP PROBE TIME AT THE TROLL
FARM

I AM PROTEUS

(Misspelled Subject corrected)
On Fri, 17 Apr 2009 04:14:40 +0100, Sandi wrote:

Some insulated multistrand copper wire is pre-tinned and a lot is not.

First, I apologize for such a long-delayed reply. Just recently resumed
USENETting after several years. The flaming was pathetic (and apparently
cross-posted, no less!). When I tried to delete the flame messages, the
Pan newsreader crashed openSUSE 11.1! Needed to reboot. Never happened
before... (Pan is typically very stable, ditto SUSE.)

Anyhow, the worthwhile messages brought a lot to mind. (I built my first
radio at 6, adapting a Meissner circuit, fwiw, and I'm 73.)

In my experience, untinned stranded insulated Cu wire is rare, and
probably meant for uncritical applications that use screw terminals.

Speaking of rare wire types, only once since 1942 have I ever seen two-
conductor cable (including line/mains power cords) that had no way to
distinguish which wire was which. Otoh, inside a Hammond tonewheel organ,
and (late 1950s) perhaps most electric-action pipe organs, multiconductor
cables had no wire ID. (I don't know about cables between consoles and
the organ proper, though.)

I didn't see any mention of fused tinned stranded Cu wire.
Although uncommon in my experience, it's nice to strip in a production
environment, yet the bonds between the strands are weak enough that they
break easily when the wire is flexed.

Coatings, whether tin, solder, or Ag, must be applied before the
individual strands are joined. Didn't see any mention of that.

I distinctly recall reading about relays (probably contactors -- for
power -- with Ag oxide/Cd contacts; iirc, those don't weld easily, if at
all, but that could be wrong.

Btw, thanks for the chemistry!

Was wondering about the term "cinch" -- whether that's a formal
engineering term; I knew them as "crimp" connectors, but I think
"compression fitting" might be the formal term. As many know, Cinch was a
company that made some fine products; dunno about its present status.
(Merged, to form Cinch-Jones, iirc, but what happened to C-J, I don't
know.)

An important point about reliable solderless connection schemes, including
properly-engineered [crimp] connectors, Wire Wrap [TM}, and Termi-Point
is that all make a "gas-tight" connection. The wire and the metal it
connects to are forced together under great pressure, typically deforming
the wire and maybe the other part as well, so the boundary between them
cannot be penetrated by gas (under ordinary circumstances, at least).

I once read that when an intermittent poor connection is suspect,
submerge the device (operating) into a vat of sulfur hexafluoride gas,
and if there's a non-gas-tight connection, it will open up!

Anybody for Cool-Amp, an electroless Ag plating prep. used for joining Cu
busbar? True, that's not for ordinary electronics, but, megawatt stuff,
more likely.

Mentions of Cu oxide reminded me of Cu oxide rectifiers, which were in
use long before Se, Ge, or Si rectifiers. Cu oxide rectifiers had low
forward drop, pretty sure, which helped in measuring low voltage AC.

(Anybody remember Mg/Cu sulfide rectifiers, btw? What was good/bad about
them?)

Apologies, and regards,

--
Nicabod =+= Waltham, Mass.
who never worked on megawatt electronics

Nicholas Bodley wrote:

Speaking of rare wire types, only once since 1942 have I ever seen two-
conductor cable (including line/mains power cords) that had no way to
distinguish which wire was which. Otoh, inside a Hammond tonewheel organ,
and (late 1950s) perhaps most electric-action pipe organs, multiconductor
cables had no wire ID. (I don't know about cables between consoles and
the organ proper, though.)

Here in the UK I've a Desk fan I inherited from my grandparents that has a
mains cable with no distinguishing marks - the cable is like a 3 core
ribbon cable with clear insulation on all 3 wires (no outer insulation),
when I was a kid I once stayed with gran in the summer and wanted to put it
on to cool the room and found someone had taken the plug off. Without
access to a multimeter I had to disassemble gran's torch and use the
battery and bulb to find the earth wire and guess the other 2. As far as I
know the plug's not been changed or rewired since.

But then again it's got no guard round the fan blades either (but motor is
so weak the blades stop easily when touched) - wasn't health & safety
ruling much more fun years ago (I've no idea how old it is, I'm guessing
40's or 50's).

On Sun, 19 Jul 2009 15:55:17 +0100, Nigel Feltham wrote:

Here in the UK I've a Desk fan I inherited from my grandparents that has
a mains cable with no distinguishing marks - the cable is like a 3 core
ribbon cable with clear insulation on all 3 wires (no outer insulation)

Enjoyed your message!

You remind me that Boston, Mass. has apparently been slow to provide AC
power everywhere. A friend says that one city building has various
voltages, some DC, and some AC. However, he's told other tall tales that
stretch credibility to the breaking point.

In the mid-1960s or so, the New Yorker Hotel was the venue of the annual
Audio Engineering Society convention. As the exhibits were being set up,
all of a sudden word got around that the outlets were DC, most likely 120
V, and UNMARKED! Apparently, line fuses and circuit breakers don't
necessarily protect their loads from burnout when the device is fed with
DC at rated voltage. (But, universal (AC/DC) motors, anyone?) Whether any
motors and/or power transformers burned out, I don't know.

As a kid, probably during WW II, I remember visiting my uncle's office on
Bromfield St. which had DC power. His desk fan motor had a lovely little
commutator plainly visible on the back; it was maybe 3/4 inch / 2 cm in
diameter, if even that big.

Afaik, the U.K. only comparatively recently standardised on those quite-
big plugs. I used to read in Wireless World about buying appliances
without plugs, because iirc there was no one national standard.

Best regards from across the big pond,
--
Nicabod =+= Waltham, Mass.
using British spelling
of one word; why not?

On Fri, 17 Apr 2009 22:54:38 GMT, Howard Eisenhauer
wrote:

:On Fri, 17 Apr 2009 04:14:40 +0100, Sandi wrote:
:
:Some insulated multistrnd copper wire is pre-tinned and a lot is
:not.
:
:What is the purpose of pre-tinned wire? As far as I can see the
:advantage is that the copper core doesn't oxidise which means the
:wire can be soldered or fixed to a terminate with only minimal
:cleaning.
:
:Sounds like a good thing to me, so why isn't almost all wire pre-
:tinned?
:
:Is cost really so different?
:
:Does the tinning-coating replace where copper would have been in
:the overall wire and tinning is of higher reistence?
:
:Is flexibility affected?
:
:
:In the telecom industry the rule is "silver on silver". Back in the
:bad old days there could be problems with diss-simmilar metals
:corroding & creating noise on circuits both from rectification effects
:& from current punch-through across the junction when voltage was
:applied to the circuit, i.e. "going off-hook". In some cases
:"sealing" current was (& still is) applied on a constant basis to
:circuits that didn't require it for operation, just to keep junction
:corrosion from getting bothersome.
:
:Although not part of the original Bellcore standard I've actually
:speced tinned wire for T1 circuits going into areas I knew were going
:going to be climate controlled.
:
:H.


That is correct. A typical manufacturer of internal switchboard cable
application chart shows that their Switchboard 100 product (equivalent to what
most western countries would use for internal cabling) is suitable for T1 and
DS1 applications.
http://www.superioressex.com/uploade...lect_chart.pdf