Electrolytic reduction of iron with silver inlay

Victoria Bullard-Smith <vbullardsmith<-at->gmail<.>com> writes

>I am a masters student at West Dean College, studying the effects of
>electrolytic reduction on small ferrous objects with silver wire
>inlay ...

For electrolytic reduction, or as it is more commonly known,
electrochemical or electrolytic cleaning, you can use a standard
industrial/academic potentiostat system.  You will need to select
the proper electrolyte and reference electrode, and you will need an
inert counter electrode, generally platinum foil (stainless steel is
also often used, but you are cleaning iron so I would not recommend
that).  If this is new to you, have a look in a basic text on
corrosion and corrosion testing.  You can also find a simple
explanation of this method in

    W. Wei, I. Gerritsen and C. von Waldthausen
    "Re-examining the (Electro-)Chemical Cleaning of Daguerreotypes:
    Microscopic Change vs. Macroscopic Perception"
    Topics in Photographic Preservation, Vol. 14, Photograph
    Materials Group of the AIC, Washington, D.C., pp. 24-40 (2012).

Actually, that article gives an example of the electrochemical
cleaning of what you have, a so-called mixed electrode.  You want to
treat two metals electrochemically at the same time.  You will thus
have to choose cleaning parameters specifically for the metal you
want to clean which do not affect the other metal.  Further you need
to be careful that nothing happens under the silver, that is, in the
"crevice" between the silver inlay and the iron.

You might also want to look at Christian Degrigny's work on the use
of capillary electrodes for local cleaning if you are only
interested in cleaning the silver inlay.  This has the advantage
that you will not have to eventually dip part of or the entire sword
into the electrolyte.  You do have to be careful of staining.  And
again, you must have the right conditions to only treat the specific
problem without affecting the other metal.

For more specific details, have a look in the corrosion and
electrochemical literature, for example, the following three
journals, Journal of the Electrochemical Society, Corrosion, and
Corrosion Science.

Dr. W. (Bill) Wei
Senior conservation scientist
Cultural Heritage Agency of the Netherlands
Hobbemastraat 22
NL-1071 ZC Amsterdam
+31 6 5273 2101


                                  ***
                  Conservation DistList Instance 30:12
                 Distributed: Saturday, August 6, 2016
                       Message Id: cdl-30-12-003
                                  ***