Consolidative reduction of lead

Suzanne Kitto <suzanne.kitto<-at->armouries<.>org<.>uk> writes

>Many years ago on my conservation course we converted lead corrosion
>back to lead.  I am looking at trying this on corroded lead bullets.
>I have my university notes but wondered if anyone had actual
>experience of carrying out this method and how successful it was?

I have carried out the reduction of many hundreds of lead objects
using the potentiostatic method as described in

    Carradice, I.A., and S.A. Campbell
    "The conservation of lead communion tokens by potentiostatic
    reduction".  Studies in Conservation, vol. 39, no. 2, pp.
    100-106, 1994

This method may be varied to allow the removal of reduced lead
corrosion products as a loose lead powder to reveal an original
surface, or the morphological form of the corrosion products may be
retained as crystals of metallic lead which remain in situ.  A
suitable potentiostat and a reference electrode such as a saturated
calomel electrode are required.  The method is very successful but
suitable acid-free post-conservation storage and display
environments should be provided to help prevent renewed corrosion of
the lead.

Will Murray ACR
Artefacts and Preventive Conservator
The Scottish Conservation Studio LLP


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                  Conservation DistList Instance 29:10
                  Distributed: Thursday, July 30, 2015
                       Message Id: cdl-29-10-001
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