Purest Green!

[Waggy]

I'm interested to see if anyone has any insight into the hard crystalline green corrosion (?) that you often see in watches. It seems particularly prevalent on rotors, see below on the watch I recently did.

From the quick search I did I am reasonably sure it is brass corrosion product, can anyone confirm? But very interested if anyone has a good way to remove it other than using abrasives?

I tried rust remover but didn't seem to do anything, and also put it in the ultrasonic with my usual detergent, again this didn't move it. I also ran through the watch cleaner with my 'home brew 111' ammoniated cleaning solution, but all to no avail. In the end I resorted to using wet and dry paper... is there a better non-abrasive (or less abrasive) solution... how do you deal with it?

Just found these home remedies, anyone tried these or have other solutions?

https://blog.thepipingmart.com/metals/how-to-remove-green-oxidation-from-brass-a-complete-guide/

Edited August 3, 2023 by Waggy
Typo

[Razz]

Looks like verdigris. In the coin collecting world a product called veridicare available fron Wizards coin supply. It is somewhat expensive but removes verdigris without a trace if it is not too far along. Very good on US cents and vintage copper pennies. In the coin collecting world condition is everything and any trace cleaning destroys a coin's collecting value so this is one product that could work more to watches that don't have to have untouched surfaces to remain valuable.

Edited September 19, 2023 by Razz
Typo fixed

[RichardHarris123]

White vinegar works.