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Bright dip


#1

How exactly does one bright dip sterling??

Marshall T. Jones
@Marshall_Jones

Hanuman
The Ganoksin Project


#2

How exactly does one bright dip sterling??

A very nasty process- an exothermic reaction using industrial
hydrogen peroxide and sodium cyanide. Not a process that you want
to do in the studio- put the sterling pieces (castings) into the
hydrogen peroxide and drop in a couple sodium cyanide eggs and
the (resulting hot!!) solution removes the copper oxides leaving
the sterling shiny. Fume hood, rubber apron, long rubber gloves,
full face protection, you really don’t want to do this.

Rick Hamilton

Richard D Hamilton, Jr.
@rick_hamilton


#3

The process Richard is referring to we always used to call
’bombing’. We’d heat up a solution of sodium cyanide (maybe a
quarter of an egg at the most) in a glass or corning container
until it steamed, and then squirt in a couple tablespoons of
hydrogen peroxide (30%). The solution would boil and foam for a
few seconds, maybe quintupling its volume, and then collapse
turning a vivid blue color from the dissolved copper. The surface
of the article (usually gold) when then have an even bright 24k
finish ready for plating or whatever. Very handy when working on
chains which couldn’t be polished, and not quite as dangerous as
it sounds. Of course, we always worked under a fume hood.

Bright dip on the other hand is (was) a commercially available
solution (Max Friedheim used to sell it) composed of a blend of
nitric, hydrochloric, and sulphuric acids (kind of a dark brown
color). You’d heat it and then just dip the sterling or gold
into it. I used it once only, I hated it.

Jeffrey Everett