On Tue, 3 Nov 2009 21:55:21 -0500, "Chris"
wrote:

I have a 55 year old door chime clock and the board has carbon arcs which is
causing a short. I have seen boards with this problem before and they were
repaired using some type of filler. What is used?

Epoxy. G10/FR4 boards are made from fiberglass matting and epoxy
binder. If your PCB is made from phenolic instead of epoxy, use epoxy
anyway. Scrape out the carbonized material. Place some PTFE tape on
one side of the hole. Hold it in place with a mess of sticky tape and
maybe a temporary cardboard stiffener. The idea is that the epoxy
will not stick to the PTFE tape. Mix some "2hr" epoxy (not the 5 min
variety) and smear it into the hole. When set, remove the tape. Let
cure for at least 24 hrs before applying power.

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