[TheForge] removing silver from the back of a mirror.

[terry l. ridder]

hello;

well like edison i now know what does not work. ;-)

acetic acid does not work.
citric acid does not work.
phosphoric acid does not work.
hydrochloric acid does not work.

doing a further search on the internet it would appear that my options
are limited to sulfuric acid ( hot concentrated sulfuric acid ) or
dilute or concentrated nitric acid.

unless i am mistaken nitric acid is not something i can purchase at
stores like lowes, farm&fleet, etc. muratic acid ( hcl ) is ready
available which is why i tried it. sulfuric acid is battery acid but i
do not particularly care to work with hot concentrated sulfuric acid.

so would anyone have any suggestions where to obtain a half-gallon or
gallon of nitric acid. actually only need about a quart.

i did find that the red shop rags turn a dark blue when hcl acid is
poured on them. ;-)

On Sat, 17 Jul 2004, Andy Vida wrote:

"terry l. ridder" wrote:
terrylr> 
terrylr> hello;
terrylr> 
terrylr> now for the problem. the mirror is etched from the back. many of the
terrylr> etchings are fine in detail there is no way for me to remove the layers
terrylr> using a 3m stripper pad. so what would be a safe ( do not want to effect
terrylr> the glass in any manner, i.e. etch the glass or scratch the glass) way
terrylr> to remove the protective layers from these fine details.
terrylr>

andy> 
andy> 	I know that nitric acid will etch away silver.  As far as I know
andy> 	it will not attack the glass.  I believe it produce silver nitrate,
andy> 	though not certain.
andy> 

terrylr>
terrylr> another note of interest is that when you look at the mirror on edge
terrylr> there is no greenish tint to the glass, it is clear. i found that
terrylr> interesting.
terrylr>

andy> 
andy> 	Typical of that sort of class.  There is a nae for it, but I
andy> 	cannot dredge it up from memory just now.  Soda glass, maybe?
andy> 

-- 
terry l. ridder ><>