The authoritative public forum
  for Metal Finishing since 1989
-----

Metal surface maintenance, fungus?

I have some trouble with a tiny metal cable connector using in my electronic equipment. I believe it is made from stainless steel with gold plated over other metals. Problem is there are tiny dark spots all over it. I normally keep it at normal room temperature, without A/C. What are they? Are they fungus? How should I remove them and prevent them in the future? Thanks.

Gun Udomsawat
- Boston, Massachusetts
2002

---

Some years ago I suggested the same idea here, that a particular black spotting might be some kind of organic growth. The inquirer applied bleach to no effect, which was sufficient to convince me that I was on the wrong track.

I think it's you turn on the wrong track. My guess, sight unseen, is that the gold is too thin and porous, and you are seeing rust or oxidation on an underlying layer of plating or on the substrate.

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
2002