[Milsurplus] contact cleaners

[Brooke Clarke]

Hi Robert:

What you say makes a lot of sense.  "But now for the rest of the story", 
as an old time radio announcer would say:
Do you do anything, except toss the foam rubber, to the contacts to keep 
them going?

My theory, and that's all it is now, is that something like Radio Shack 
"Lube Gel" applied in a thin coat would tend to keep the contacts 
working longer than they would just bare.

Any Thoughts?

Brooke Clarke, N6GCE
http://www.PRC68.com
PS I don't own Radio Shack/Tandy stock, but I do think that "Lube Gel" 
is a modern miracle worker.

WA5CAB@cs.com wrote:

> Brooke, George and group,
>
> I'll second George's comments from fairly extensive and long term 
> experience with vibrators.  Some ten years ago, I began to notice that 
> vibrators packaged prior to VJ day and never opened and used since 
> then had a near 100% probability of not working.  Within the past year 
> or two, the same problem has started to show up in those packaged 
> during the Korean War.  Used units that were in service into the 
> Vietnam War period will usually still work the first time you apply 
> power, regardless of their actual original vintage.  The only 
> exception that I am aware of is the VB-16 used only in the PE-237.  
> Aside from physical size (it is the largerst vibrator that I have ever 
> come across) and number of contacts, the significant difference 
> between it and all of the others is that it does not have a sponge 
> rubber sleeve around the mechanism inside the outer can or cover.  The 
> culprit is sulpher from the sponge rubber.  After 40+ years, I can't 
> recall which suplher compound it actually forms with the silver, but 
> chemical cleaners don't help (and you have to open up the vibrator to 
> apply them anyway).  The two fixes are either mechanical abrasion 
> (contact burnishing tools, which also requires opening the crimped 
> seal) or electrical punch-through.  I normally use the latter method.
>
> In a message dated 10/3/2003 8:16:30 PM Central Daylight Time, 
> gl4d21a@juno.com writes:
>
>> One of the misunderstood aspects of the contact problem is that it is
>> rarely as simple as oxidation.  This is apparent when you consider the
>> silver plating on many switches and connectors.  Silver oxide is a fair
>> conductor, which is why it is chosen.  Other compounds of silver do not
>> fare so well.  Gold is not supposed to corrode at all.  HA!  One of the
>> principal offenders is sulfur, which migrates out of most old rubber
>> products.  
>
>
>
> 73
> Robert Downs - Houston
> <http://www.wa5cab.com>
> <wa5cab@cs.com>



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