What is the purspose of pre-tinned wire?

I guess they assume you do not need to cut it to length. It probably solders easier or stay in a pinch connector better.

Reply to
Van Chocstraw
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One of the unmentioned uses is in kits. Tinned wire reduces the chance of a bad connection made by someone inexperienced in soldering. (I didn't say it eliminated the chance.)

Reply to
William Sommerwerck

Aren't these problems are surely to do with contamination of the wire plating by the insulation rather than inherent characteristics of the plating?

Worldclass Wire & Cable's catalogue has several charts comparing the properties of the insulation including one on fluoropolymers. However they don't seem to worry much about soldering probably because maybe they presume their users (usually military subcontractors) will clean the wire.

Reply to
Johannes

I don't know Mr Haney or you but AFAICT he seems to write sensibly, accurately and with some knowledge of what he is discussing. I'm prepared to accept what he writes.

Could you cut the noise down please. Thank you.

Reply to
Tyrorex

Tarnish is silver sulphide. It is no oxide. The tarnishing process is as follows..

8Ag + 4HS(-) 4Ag2S + 2H2 + 4e-

Oxygen in the form of a water film is required - silver will not tarnish in dry air. This reaction mops up the electrons lost in the oxidation process

O2 + 2H2O + 4e- 4OH(-)

Although the reaction is a classical redox process the end product is not an oxide - it is assuredly silver sulphide.

Since I'm sure there will be a deal of shouting from people about how this is bollocks, I would point out I have a degree and masters in the field and spent a lot of time researching silver adsorption reactions for silver oxide cells and lead acids - I do know what the deal is here.

As fo silver oxide being conductive - the biggest problem in a silver cell is the extra graphite needed to make it conduct - silver oxide is a p-type semiconductor. Silver sulphide is mode conductive than copper oxide though by a long way and is usedful because then the silver coat tarnishes it does not reduce the skin effect like the dielectric coating of copper oxide will.

Reply to
Chris Street

I own a couple of antenna that are silver plated for that reason !

Reply to
Baron

Duh. That's what I said. "especially when it is inside teflon".

The FLUX 'cleans the wire' you dippy ditz.

The cases notes are where NORMAL soldering processes do NOT yield favorable results.

It is pretty obvious for anyone with an inkling of common sense.

Reply to
Mr. Haney

No. You are correct.

Reply to
Mr. Haney

You're an idiot, then. DimBulb (latest sock puppet, "Mr Haney") went out of his way to earn the name "AlwaysWrong".

Well, there you have a point.

Reply to
krw

If you will please just go away, the noise issue will resolve itself ;-)

...Jim Thompson

Reply to
Jim Thompson

You don't understand what "oxidation" means.

Reply to
William Sommerwerck

I most assuredly do as I pointed out in the post above. The suplhide is an oxidation product but it is most assuredly not an oxide as has been claimed several times.

Reply to
Chris Street

Ou, bad move!

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Reply to
Jamie

Well I suppose if you were to use the wire with in a normal time from the manufacturing date, you wouldn't need to use that flux would ya?

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Reply to
Jamie

Solder comes with flux, you total idiot, and solder processes all use flux as well.

That borders on being one of the most stupid posts you have ever made, Jamie.

Reply to
Mr. Haney

"Tyrorex" >"Mr. Haney"

** You need to see a shrink - ASAP.

Cos you are totally NUTS.

Look up " silver tarnish " on Google for f*ck's sake.

..... Phil

Reply to
Phil Allison

All he understands is trolling for attention

Reply to
Michael A. Terrell

: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.

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Reply to
Ross Herbert

Reply to
John Fields

No, oxide/sulfide is not what makes DimBulb a dope.

Reply to
krw

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