[TheForge] removing silver from a mirror

[James Binnion]

Hi Bruce,

	From experience Aqua Regia has problems with dissolving high 
silver content metals. Not being a chemist I am not clear on the 
exact reaction but it is my understanding that silver chloride is 
formed by the action of the hydrochloric acid on the silver. The 
silver chloride is not soluble in the aqua regia and acts as a resist 
to the further action of the acids. In etching high silver content 
gold alloys with aqua regia you must occasionally remove the item 
being etched and rinse it in water  then place it in aqua ammonia to 
dissolve the silver chloride then rinse and return to the aqua regia 
bath for further etching. I have never tried to use aqua regia to 
dissolve pure or sterling silver as nitric does that just fine so I 
don't know about the action of aqua regia on pure silver but I would 
assume that the formation of silver chloride would occur then as well.

	Also ferric nitrate is indeed a good etchant for silver.

BTW Terry did you get your ferric nitrate and did it do the trick on 
the mirror?

-- 
Jim Binnion

James Binnion Metal Arts
Phone (360) 756-6550
Toll Free (877) 408 7287
Fax (360) 756-2160
http://www.mokume-gane.com
jbin at mokume-gane.com
Member of the Better Business Bureau