| oliverotuns@gmail.com: Jun 21 05:31AM -0700 i need Solution Manual Electronic Principles (8th Ed., Albert Malvino, David Bates) pdf for 8th edition |
| "pfjw@aol.com" <peterwieck33@gmail.com>: Jun 20 10:00AM -0700 On Thursday, June 20, 2019 at 4:14:18 AM UTC-4, GS wrote: > 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. "Silver Paper" has been around since the 1800s, invented/developed in England when burning high-sulphur coal was common both for heat and for "town gas" that powered street lights. In that environment the "Plate" would tarnish almost overnight, requiring dedicated servants for its maintenance. Still around today: https://www.amazon.com/3M-Anti-Tarnish-Silver-Protector-Strips/dp/B00O89A21Q As a related 'aside', fine silver is much more resistant to tarnish than Sterling or Plate-silver. So drinking vessels and those made to serve food typically had a fine-silver wash on the contact surface. Peter Wieck Melrose Park, PA |
| Jeff Liebermann <jeffl@cruzio.com>: Jun 20 03:20PM -0700 On Thu, 20 Jun 2019 08:14:16 -0000 (UTC), gregz <zekor@comcast.net> 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=3f8d8512c835e9a69f64&whence=> Mentions "mineral oil" twice. >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 jeffl@cruzio.com 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 |
| gregz <zekor@comcast.net>: Jun 21 08:13AM >> pads to stick inside sensitive equipment said to protect. Never tried them. > There are several types of RTV. Some have the acedic acid and eats > copper, and some does not have the acid and is fone with copper. I used acedic type. I don't know what remnants remain. The smell goes away. Greg |
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