Zinc wall

At the new Museum Victoria building in Melbourne we have a major
indoor contemporary Australian Aboriginal art work as an
architectural feature. 'Wurreka' is a 50 meter long zinc wall by the
artist Judy Watson. It is thought to be the largest contemporary
Aboriginal art work in Australia.

The wall consists of a band of decorative etched panels surrounded
by many pristine, highly polished zinc panels. The zinc is known as
'Rhinezink,' a patented alloy. According the trade information it is
95.995% zinc, with copper and titanium. The wall is designed to
develop a zinc oxide patina over time. There is little literature on
the cleaning and protection of pristine contemporary zinc sculpture,
as most conservation literature refers to outdoor objects where the
surface has already been compromised by the elements.

The Conservation department has two issues to solve. The first is
that while the artist wishes the wall to develop a patina over time,
(and therefore initially we chose not to coat the wall) it is
currently highly sensitive to etching by fingerprints. As we have
many visitors, including school children, there are already many
unsightly fingerprints etched into the sensitive zinc surface. Our
recommendations to place barriers in front of the wall to prevent
touching were not heeded. We now have a damaged zinc surface, and
pressure to 'clean' the prints off. I  have ruled out most abrasive
techniques as the wall is too sensitive and too big to withstand
this type of local cleaning and remain aesthetically pleasing.

We have initiated a cleaning schedule using petroleum spirits and
soft cloths  to remove greasy marks before they etch the surface,
but this does not solve the problem of those existing.

The second issue is that now we are considering a coating. Several
tradespeople have suggested that the use kerosene is an old trick
for these types of architectural features as the oily residues offer
some protection to the zinc. I am wary of this approach, and instead
am considering a coating of a microcrystalline wax. Some references
in the literature refer to the use of acrylic coatings. However,
once a coating is applied, the development of a patina will, of
course, be compromised.

I would be interested to hear from any experienced metal
conservators on possible cleaning and coating systems for this
unique zinc object.

Penny Edmonds
Senior Conservator
Museum Victoria


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                  Conservation DistList Instance 14:36
                Distributed: Wednesday, January 3, 2001
                       Message Id: cdl-14-36-016
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