I use sparex to remove oxidation on silver (heated in a small crock
pot). When the sparex is new, all silver comes out a dull white
color. After several weeks of use (I’m a hobbyist), the sparex
stops removing all oxidation. I’ve noticed that when I remove the
metal from this older sparex, it’s silver but when I dip it in water
that has a little baking soda (to neutralize the acid), a
goldish/greenish film/layer forms on the metal that can be partially
wiped off with a paper towel when still wet (of course, the film can
be polished off). This is probably just normal behavior for sparex
when it needs to be changed but I just thought I’d ask to make sure
I’m not doing something stupid. Once this film is on there, it’s
not easy to remove.
A related problem: I pickled a hand-woven chain in sparex and the
"old sparex" film formed on the chain. How do I best remove this
film (the chain is sort of hand-knitted in a hollow circle so it’s
hard to clean with a brush)? I’ve tried baking soda and salt on a
tooth brush but it’s not as clean as I would like. I do not have an
ultrasonic cleaner – would one of these remove this film?
Thanks in advance (I learn a LOT from this forum!),
Elizabeth