Hello all,
I bought this 1930s French wrought iron Art Deco mirror recently .......
Now folks, I don't think Mittens' mirror has a mercury based coating, because ....
The invention of the silvered-glass mirror is credited to German chemist Justus von Liebig in 1835. His process involved the deposition of a thin layer of metallic silver onto glass through the chemical reduction of silver nitrate. This silvering process was adapted for mass manufacturing and led to the greater availability of affordable mirrors. http://wikirank.com/en/Mirror
A silvered-glass mirror is made by depositing a layer of
pure silver on the glass and then "painting" it over with a protective coating to protect it from the Oxygen in the air. If not, the silver will "oxidize" just like your tea pot, etc. The protective coating is most always "black" in color thus preventing any light from entering through the backside, except in cases of "two way mirrors" like you see in police movies.
I first learned how to “silver” glass in Chemistry Lab. Wash the glass clean, immerse it in formaldehyde (I think it was) and then pour in some silver nitrate. The two will react and the pure silver will be deposited in a very thin layer on top of the glass. If one uses copper nitrate they get a copper mirror.
Anyway, the chipping and flaking can be caused by two things. 1. The silver didn’t adhere to the glass that good (for whatever reason) and age has caused it to flake off. 2. A tiny nick or scratch of the “protective coating” will permit the oxygen in the air to start a “cancerous” oxidation of the silver. The more it oxidizes and flakes off, the more of it will be exposed to the oxygen.
A “cheapy” fix for an old mirror, …. remove it from its frame, clean all the old “silvering” off, wash it impeccibly clean, buy a real thin “cheapy” mirror, cut it to fit the frame, wash it impeccibly clean, replace the old glass in the frame, place the “cheapy” mirror behind it, and seal it all up. No one will ever know unless they take it back apart.