Thiourea is an acid. Any acid, repeatedly used on any silver will
damage the silver, gradually eating it away. I would recommend that
you tell people who buy your work that if it tarnishes, use the
aluminum foil/hot water/baking soda method to safely remove
Hmmm…something about the distinction being made here strikes me as
a bit fishy.
To form tarnish, the metal surface has reacted with atmospheric
gases to form metal sufides/oxides.
Isn’t it the case that regardless of how one removes this tarnish,
the metal that was reacted to become tarnish is gone from the
surface? If it is otherwise, then one has to believe that the
tarnish “removal” process is actually reducing the metal
sulfides/oxides back to metal AND that the resulting metal is well
integrated into the surface (rather than perhaps becoming an easily
disrupted layer on the surface).
I’ll buy that the thiourea is reducing the sulfides…and giving you
just the slightest whiff of hydrogen sulfide to let you know it is
working. It’s the fate of the newly reduced metal that I can’t swear
Unless of course I’m thinking about this in some fundamentally wrong
way…wouldn’t be the first time…
Me, I love that Tarnex. I’m under no illusions, though, about its
impact on the pieces being cleaned. If you want your silver to last
forever, the only solution is to keep in from tarnishing in the
first place. I find those little pieces of black paper (3M brand, I
think I got mine from Rio) treated with sulfur scavenging stuff work
great. I keep a few in the air tight containers in which I store my
silver chain samples and I haven’t seen any tarnish to speak of
since I started doing so. Maybe not so convenient for the jewelry
box, but they work!
…looking over my shoulder, hoping a real metallurgist is lurking
about who can clue me in…anyone seen Jim Binnion lately?