Posted by Sherman in Idaho [108.162.245.55] on Saturday, February 18, 2017 at 11:33:22 :
In Reply to: Chemically Cleaning Brass posted by Greg Coffin [172.68.34.103] on Friday, February 17, 2017 at 23:51:19 :
Any dilute acid, as mentioned, will clean the tarnish off. The problem I usually find with old switches and other electrical devices is that they were assembled with tubular rivets connecting various parts and the connection between the rivet and what it goes through has gotten corroded. There's no good way to clean that contact other than disassembling it and putting a new rivet in, and then you'll have to go through the whole process again in another 60 or 70 years. What I prefer to do is clean up the brass rivet and whatever it goes through and then solder it. The housings are usually ceramic or bakelite plastic which can take the soldering heat. Or sometimes I'll run a small wire to bypass the rivet connection entirely. Solder is always more reliable than mechanical connections.