What is the purspose of pre-tinned wire?

[Sandi]

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?

 

[Ross Herbert]

On Fri, 17 Apr 2009 04:14:40 +0100, Sandi <invalid@email.com> 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.

 

[Steve Terry]

"Sandi" <invalid@email.com> wrote in message
news:Xns9BF02B2DB25E3628D1@news.albasani.net...
<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

 

[Eeyore]

Steve Terry wrote:

"Sandi" <invalid@email.com> 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

 

[Phil Allison]

"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

 

[Pilgrim]

In article <gs9gt7$uk9$1@news.albasani.net>,
"Steve Terry" <gFOURwwk@tesco.net> wrote:

"Sandi" <invalid@email.com> wrote in message
news:Xns9BF02B2DB25E3628D1@news.albasani.net...
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.

 

[GregS]

In article <pilgrim-AB916B.05415017042009@70-3-168-216.pools.spcsdns.net>, Pilgrim <pilgrim@noemail.net> wrote:

In article <gs9gt7$uk9$1@news.albasani.net>,
"Steve Terry" <gFOURwwk@tesco.net> wrote:

"Sandi" <invalid@email.com> wrote in message
news:Xns9BF02B2DB25E3628D1@news.albasani.net...
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

 

[Sandi]

On 17 Apr 04:49, Ross Herbert wrote:

On Fri, 17 Apr 2009 04:14:40 +0100, Sandi <invalid@email.com
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?

 

[Steve Terry]

"Pilgrim" <pilgrim@noemail.net> wrote in message
newsilgrim-AB916B.05415017042009@70-3-168-216.pools.spcsdns.net...

In article <gs9gt7$uk9$1@news.albasani.net>,
"Steve Terry" <gFOURwwk@tesco.net> wrote:

"Sandi" <invalid@email.com> wrote in message
news:Xns9BF02B2DB25E3628D1@news.albasani.net...
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

 

[Ian Bell]

Sandi wrote:

On 17 Apr 04:49, Ross Herbert wrote:

On Fri, 17 Apr 2009 04:14:40 +0100, Sandi <invalid@email.com
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

 

[Salmon Egg]

In article
<pilgrim-AB916B.05415017042009@70-3-168-216.pools.spcsdns.net>,
Pilgrim <pilgrim@noemail.net> 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!

 

[Spehro Pefhany]

On Fri, 17 Apr 2009 15:18:30 +0100, "Steve Terry" <gFOURwwk@tesco.net>
wrote:

"Pilgrim" <pilgrim@noemail.net> wrote in message
newsilgrim-AB916B.05415017042009@70-3-168-216.pools.spcsdns.net...
In article <gs9gt7$uk9$1@news.albasani.net>,
"Steve Terry" <gFOURwwk@tesco.net> wrote:

"Sandi" <invalid@email.com> wrote in message
news:Xns9BF02B2DB25E3628D1@news.albasani.net...
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.

 

[Tim Shoppa]

On Apr 17, 8:41 am, Pilgrim <pilg...@noemail.net> wrote:

In article <gs9gt7$uk...@news.albasani.net>,
 "Steve Terry" <gFOUR...@tesco.net> wrote:

"Sandi" <inva...@email.com> wrote in message
news:Xns9BF02B2DB25E3628D1@news.albasani.net...
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

 

[David Nebenzahl]

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/)

 

[Dave Platt]

In article <pilgrim-AB916B.05415017042009@70-3-168-216.pools.spcsdns.net>,
Pilgrim <pilgrim@noemail.net> 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 <dplatt@radagast.org> 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!

 

[GregS]

In article <vdumb6-6ch.ln1@radagast.org>, dplatt@radagast.org (Dave Platt) wrote:

In article <pilgrim-AB916B.05415017042009@70-3-168-216.pools.spcsdns.net>,
Pilgrim <pilgrim@noemail.net> 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.

 

[GregS]

In article <gsajee$d6b$1@usenet01.srv.cis.pitt.edu>, zekfrivo@zekfrivolous.com (GregS) wrote:

In article <vdumb6-6ch.ln1@radagast.org>, dplatt@radagast.org (Dave Platt)
wrote:
In article <pilgrim-AB916B.05415017042009@70-3-168-216.pools.spcsdns.net>,
Pilgrim <pilgrim@noemail.net> 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 !

 

[Ian Bell]

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

 

[Steve Terry]

"Mike" <youmustbej@king.com> wrote in message
news:gsao5i$m0u$1@news.albasani.net...

"Steve Terry" <gFOURwwk@tesco.net> wrote in message
news:gs9gt7$uk9$1@news.albasani.net...
"Sandi" <invalid@email.com> wrote in message
news:Xns9BF02B2DB25E3628D1@news.albasani.net...
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

So how high does the frequency have to be for skin effect to matter?

(I have killed the cross posts to stop the usual abuse from being seen
outside uk.radio.amateur)
Mike

Beats me?

Steve Terry

 

[Sandi]

On 17 Apr 16:22, Salmon Egg wrote:

In article
pilgrim-AB916B.05415017042009@70-3-168-216.pools.spcsdns.net>,
Pilgrim <pilgrim@noemail.net> 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?