Anthropological museum collection including both ethnographic and archaeological materials
comprises a documented objects acquired by the museums for the sole purpose of education,
entertainment and enlightenment of the public. It’s an array of display of cultural and historical heritage
that reminds man of past civilization.
The source of cultural property in a museum are varied. The objects may come through exploration,
excavation, treasures trove finds, through purchase, gifts, transfer or even loan. Materials used in
making the objects, could be organic- examples are wooden object, fabrics and textiles, leather etc.;
inorganic example are metallic, both pure or in their alloys, gold, silver, iron, bronze and brass, both
copper alloys etc.; stones source example clay, etc. cellulosic materials example films.
Metals are materials of great strength and flexibility (of manipulation) than other materials such as clay,
stone or wooden objects. This is achieved with the use of high temperature during fabrication thereby
changing the physical and chemical properties of the metal. Deterioration of the metal object is as a
result of the formation of compounds in the form of oxides. The ores which occurs in their natural form
mined are reduced during fabrication to pure metal objects . These fabricated metallic object exposed
over time and under environmental conditions begins corroding, thereby making corrosion, a menace
conservator face.
Metallic objects in the museum exposed to new environments face deteriorating factors such as
fluctuations in relative humidity, temperature, moisture from poor handling, poor storage and of course
lack of maintenance and monitoring. This is why the conservator has to tackle the problems head on, so
as to preserve and restore these cultural and historical heritage.
Conservation of the metallic objects can be done by removing and/or arresting further corrosion
elements that have been accumulated over time and under environmental conditions. Both scenario can
be achieved by use of physical method, chemical method, and electrochemical (electrolytic) method.
Physical method using simple mechanical tools like chisel, scalpel, pins, etc. can be used to remove the
unwanted corrosion products on the metallic objects like bronze, iron artefacts etc. A final emery sheet
to bring out the inner patina layer to relief adding aesthetic beauty to the metallic objects. For certain
patina can also act as protective coat for the metallic objects.
Chemical method involves the use of chemicals like very diluted solution like ethanol. One must
understand that the use of a particular chemical solution is determined by the type of metallic objects
and the corrosion deposits. If chloride are present in bronze antique, carbonate solutions is used to
remove the unwanted chloride. Lead objects are treated with 5 percent acetic acid. However, these chemical
intervention techniques calls for extreme care. Chemical method may introduce additional chemicals or
products of chemical changes on the metallic artefacts. This kind of chemical intervention is a form of
curative conservation restoration and treatment.
The electrochemical method involves the reduction of corrosion (oxidation) products using reductive
electrolysis. However, this electrolytic reduction is done for the restoration treatment of coins and inscribed plates. It is not recommended for most metallic object in the museum collection, as it’s quite
technical. It’s only advisable for badly corroded bronze icons
