Tarnished silver is a great conductor, it will not solder easily.

Diodes with silver leads were easily ruined if not kept in a nitrogen box.
Attempts to clean the leads would have the cleaner or flux eat into
the glass diode.
The diodes were scrap if tarnished.

I am testing air in a factory now for the sulfur causing tarnish on
immersion Ag PCB's.  The Immersion Sn show no effect. The suspect is
the drywall, new construction or an industrial chicken farm at the end
of the industrial park.or some other source. Same process, materials
and equipment do not see this effect at a different factory with
greater humidy swings from 10% to 85%.

On 6/6/12, Goodyear, Patrick <[log in to unmask]> wrote:
> HMMM, NOS I can understand mainly with electronic assemblies and not car
> parts though.
>
> I seem to remember from my High School and College Chemistry and Physics
> classes that tarnished Silver is a better conductor then the clean silver,
> considerably.    I remember that being drilled into our heads in Navy ET
> school as well that one was never to "clean" silver connectors and that was
> why all Mil-Spec RF connectors were silver plated.   I want to remember that
> Silver Oxide was right next to bare clean copper in conductivity.   I
> believe even the lugs connecting to the high voltage buss work were silver
> plated.
>
> I know when we make connections at the power plant the electricians use a
> silver plating powder (Cool-Amp) to coat the connection point, this is
> especially true with aluminum wiring.
>
> Cardboard is a great storage medium, it absorbes moisture, just don't want
> to get it soggy.
>
> Pat
>
> -----Original Message-----
> From: TechNet [mailto:[log in to unmask]] On Behalf Of Mike Fenner
> Sent: Wednesday, June 06, 2012 11:06 AM
> To: [log in to unmask]
> Subject: Re: [TN] Electronic assemblies packaging
>
> Probably, it certainly is a short range force as it only works near
> transmitters.
>
>
>
> Regards
>
>
> Mike
>
>
>
>
> -----Original Message-----
> From: TechNet [mailto:[log in to unmask]] On Behalf Of Whittaker, Dewey
> (EHCOE)
> Sent: Wednesday, June 06, 2012 4:58 PM
> To: [log in to unmask]
> Subject: Re: [TN] Electronic assemblies packaging
>
> Of course the solder joints on your radio are still shiny due to all the
> string theory buffs.
> Dewey
>
> -----Original Message-----
> From: TechNet [mailto:[log in to unmask]] On Behalf Of Mike Fenner
> Sent: Wednesday, June 06, 2012 8:48 AM
> To: [log in to unmask]
> Subject: Re: [TN] Electronic assemblies packaging
>
> Dampness will improve the static dissipation properties of the card, for
> other properties I offer a personal observation rather than rigorous data:
> I own an old car (~50 years) and am always on the look out for what is known
> as N.O.S. parts. Especially electrical parts like switches, dials/gauges
> etc. For non classic car fans, "NOS" means new old stock. In other words the
> parts are also 50 or more years old, but have not been used so are in
> original packing - cardboard. [This is not for sentimentality but because
> the original old stock is better made than modern reproductions and does
> things like work and fit.] Terminations on this old stuff are nearly always
> perfectly clean and shiny, although the boxes are usually a little sad.
> Soldered joints are bright, but what would constitute tracking (very thing
> copper pieces in some gauges) is usually dull.
> 50 years is about 40 more than the planned storage time and predates nearly
> all auto electronics, so can't comment on that. [Although I do have a rather
> modern late 1960s early 70s radio complete with push button tuning - string
> operated of course!]
>
> Regards
>
>
> Mike
>
> Bonding Services & Products
> M: +44 [0] 7810 526 317
> T: +44 [0] 1865 522 663
> E: [log in to unmask]
>
>
>
>
> -----Original Message-----
> From: TechNet [mailto:[log in to unmask]] On Behalf Of Jack Olson
> Sent: Wednesday, June 06, 2012 3:23 PM
> To: [log in to unmask]
> Subject: Re: [TN] Electronic assemblies packaging
>
> Maybe I missed something, but that article didn't seem too enlightening.
> Isn't it common knowledge that bare copper will tarnish?
> and that silver coatings need to be protected with "silver saver" paper or
> some type of good packaging until used?
> (a "no brainer" study, if you ask me...)
>
> It might not be wise to store "piles of reels" in cardboard boxes for nearly
> a decade, but the component termination plating on those probably aren't
> copper or silver.
>
> I thought the original question was about shipping final product, not about
> wettability.
> What is the danger of shipping AFTER SOLDERING in cardboard?
> Maybe not the cardboard,
> probably the moisture.
>
> Jack
>
> .
> On Tue, 5 Jun 2012 20:33:27 -0400, Robert Kondner
> <[log in to unmask]> wrote:
>
>>Hi,
>>
>> Having used card board shelving supplies for years I was curious. I
>>heard about solderability issues but never noticed issues. So I was
>>wondering if this was hogwash or not.
>>
>> So I did a little web look up and found this note:
>>
>>www.kondner.com/files/cardboard_soldering.pdf
>>
>>Now I have parts in plastic bags and the cardboard containers do have
>>small holes, that might help vent. Our temperature is lower probably
>>around 20 - 23C.  But the result in the paper were a BIG surprise.
>>Likes like it is a real issue and NOT hogwash.
>>
>> I have a pile of 1206 reels that have been sitting in a card board box
>>without plastic bags for maybe 10 years. I will need to take a look.
>>
>>Bob K.
>
>
>
> ______________________________________________________________________
> This email has been scanned by the Symantec Email Security.cloud service.
> For more information please contact helpdesk at x2960 or [log in to unmask]
> ______________________________________________________________________
>
> ______________________________________________________________________
> This email has been scanned by the Symantec Email Security.cloud service.
> For more information please contact helpdesk at x2960 or [log in to unmask]
> ______________________________________________________________________
>
>
>
> ______________________________________________________________________
> This email has been scanned by the Symantec Email Security.cloud service.
> For more information please contact helpdesk at x2960 or [log in to unmask]
> ______________________________________________________________________
>
> ______________________________________________________________________
> This email has been scanned by the Symantec Email Security.cloud service.
> For more information please contact helpdesk at x2960 or [log in to unmask]
> ______________________________________________________________________
>

______________________________________________________________________
This email has been scanned by the Symantec Email Security.cloud service.
For more information please contact helpdesk at x2960 or [log in to unmask] 
______________________________________________________________________