On Sun, 11 Sep 2011 16:57:02 -0700, (Dave Platt)
wrote:

For open frame
relays, I sometime use electroless silver to replate the contacts.

Is that Cool-Amp (powder), or some form of liquid electroless silver?

http://www.cool-amp.com/cool_amp.html
That's silver chloride and calcium carbonate powder. $25/oz. Ouch.
I've used Cool-Amp immersion plating (it's not really electroless). It
works well for PCB and contact plating. You might find this of
interest:
http://yarchive.net/electr/pc_board_silver_plating.html

What I have is:
http://www.transene.com/ag.html
I think (not sure) it's a silver nitrate, ammonia, sodium hydroxide,
and who knows what else mix. One catch is that it has to be applied
warm, which is somewhat of a challenge. I'm sure easier to use stuff
exists, but I didn't pay much for the 1 oz bottle which seems to be
lasting forever. When I run out in about 10 years, I'll look at
alternatives.

Mo
http://www.finishing.com/faqs/silverathome.shtml

I've made up (and use) a homebrew substitute for Cool-Amp - silver
chloride and salt, finely ground, and then rubbed in firmly. Makes a
nice, solderable surface for DIY PC boards.

Nice, but don't use salt. Use calcium carbonate instead. Salt
(sodium chloride) might precipitate the silver out at silver chloride.


--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558