In article , Jim Yanik wrote:
(GregS) wrote in
:

In article , "Michael
A. Terrell" wrote:

GregS wrote:

In article
,
Dubtron wrote:
On Sep 18, 10:28=A0am, GeneO wrote:
Have been Googling the proper way to clean plated electrical
contacts but either get nothing if use " or a lot of nonrelevant
hits without.

Am interested in any suggestions esp how to remove the
nonconductive oxides.

If a connector is too damaged would also be interested in what
are considered the best type replacement.

Thanks

Gene

I have had very good luck repairing low current relay contacts and
mechanical rotary switches using "tarn-x" silver cleaner containing
acidified thiourea. MSDS:
http://www.jelmar.com/msds/TX_MSDS_eng.pdf. If you take the relay
or switch apart to get to the contacts, use a cotton swab with a
small amount of cleaner and apply to the oxidized (tarnished)
surfaces. They shine right up and the surface does not appear to be
damaged by it. Then dry and apply a very light film of silicone
based contact cleaner to keep the air away and help with
lubrication. Works great for speaker relays in amplifiers and mode
switches for VCR's.


Silicone based products are really not a good thing, at least thats
what some say. However sometimes a silicone grease is used to
protect connections. Silicone sprays were common 30 years ago.
I don't recall any of the more common recommended sprays having
silicone. I see mixed recommendations of lubing relays.
Some say no, but I do.


Silicone based chemicals were banned from all telephone switching
centers with mechanical switching.

The old General Cement "Tuner Lube" is petroleum based and doesn't
build up an insulating film like Silicone based products.

contact wiping pressure should handle that "insulating" film.
Only TEK "HF switch contacts" didn't have enough wiping pressure to deal
with films left from tuner cleaner/lube sprays.

I got some of that stuff. For rubber and some plastics
petroleum based products can hurt. I have been using plastic safe
liquid CRC 2-26 but I really don't know whats in it. For those outside
the US, if you use Cramolin Contaclean, it must be removed after
cleaning because it will gum. Here is an old
can. Check out the buildup at the top.

http://zekfrivolous.com/misc/cramolin%20contaclean.JPG

greg


I used to use Tarn-X on TEK 500 series tube scope rotary switches,to clean
off the black oxidation.
It worked great,had to wash and oven-dry the scopes anyways.
You must RINSE the contacts after using Tarn-X on them.


Been there. I love big silver plated ceramic switches.

A friend used to say, he liked using both Cramolin Red
and Tweek on contacts, together.

The current Caig R100 full strength is also great.

greg