Brass

Samantha de van Geer <sam.vandegeer [at] oxfordshire__gov__uk>
writes

>I am wondering if anyone can advise me on the more appropriate
>conservation materials for cleaning Social History post-18th century
>brass. ...

Wyatt Yeager <weyeager [at] comcast__net> responded

>Have you considered a pre-soak in Sodium Sesquicarbonate or Sodium
>Hexametaphosphate followed by a treatment with BTA or Incralac? ...

Although sodium sesquicarbonate was recommended at one time for
treatment of copper alloys, it is no longer considered safe.  This
double-carbonate removes copper from the metal surface (as does
ammonia).  Also, brass is vulnerable to dezincification from both
alkaline and acidic solutions, so care must be taken with any
cleaning product.

Terry Drayman-Weisser
The Dorothy Wagner Wallis
Director of Conservation and Technical Research
The Walters Art Museum
600 N. Charles Street
Baltimore, MD  21201
410-547-9000 ext. 291
Fax: 410-837-1274


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                  Conservation DistList Instance 22:50
                  Distributed: Tuesday, March 3, 2009
                       Message Id: cdl-22-50-003
                                  ***