On Thu, 20 Jun 2019 08:14:16 -0000 (UTC), gregz
wrote:

In watching the video, I was wondering how the Rtv acedic acid reacted with
steel. I coated and removed cured rtv from copper sheet, no corrosion.

"Can acetic acid dissolve steel?"
https://www.quora.com/Can-acetic-acid-dissolve-steel

"What are the products of acetic acid and copper?"
https://www.quora.com/What-are-the-products-of-acetic-acid-and-copper

Any mild acid (including oleic acid) will remove the oxide layer from
copper. However, if left on the copper contacts, it will eventually
corrode the copper. This is the label from a bottle of Cramolin red,
from when it contained oleic acid:
http://www.learnbydestroying.com/jeffl/pics/Cramolin%20R-100L/index.html
"Wipe off excess with a lint-free cloth or swab."

Ancient Cramolin R100L MSDS data:
http://store.caig.com/core/media/media.nl?id=808&c=ACCT113328&h=3f8d8512c835e9a69f6 4&whence=
Mentions "mineral oil" twice.

Whatever it was, I removed old NOS stuff like silver plated switches.
Around the switch was a piece of paper looking sheet. One side said towards
part. Any part sticking out of paper had turned black. I still have some
pads to stick inside sensitive equipment said to protect. Never tried them.

That's tarnish (sulfur compounds). Some clues from how to clean brass
clock mechanisms:
https://www.snclocks.com/TechnicalInformation/Tid-Bits/Clock-Cleaning-Solution/

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