Preventing damage and understanding the collections
The old adage that 'prevention is better than cure' certainly holds true for collections. Protecting collections from damage is a vital part of the work that goes on behind the scenes at the National Museum of Australia.
Preventive conservation requires a continuous cycle of work involving expertise from the Museum’s Conservation, Registration and Facilities staff.
Providing stable storage conditions
All the items in the National Museum's collection will deteriorate over time – this is a natural process but we can slow the rate of deterioration in many ways. Providing stable storage conditions appropriate to the types of materials in the collection is a first line of defense. Not all objects require the same storage conditions, so it is important to understand the materials that make up each object in order to place them in their optimum storage environment. The National Museum has a range of storage environments in its main building and off-site repositories, and these have to be maintained and monitored.
Protective bubbles
Carcoons provide a specialised protective environment for the Museum's vehicle collection.
Cars are susceptible to metal corrosion and their painted surfaces are easily scratched. Dust can be highly abrasive and contain chemically active components that corrode metal surfaces over time.
Inside the Carcoon's protective bubble, fluctuations in temperature and humidity are reduced and the air is filtered to prevent dust from settling on the vehicle.
Materials analysis
Given the different characteristics of different materials, it is important that conservators know what they are dealing with. This is where various analytical techniques come to the fore.
X-ray fluorescence
One technique the Museum's staff use quite regularly is X-ray fluorescence (XRF). X-ray fluorescence provides information about what elements are present in a material. It is a non-destructive technique for identifying metals and investigating the composition of materials such as paints, glass and ceramics. When a test piece is bombarded with high-energy beams from an XRF machine, it gives out secondary X-rays that provide a unique ‘fingerprint’ of the elements making up the material.
X-ray fluorescence can also be used to check for the presence of hazardous elements such as mercury and arsenic, or to authenticate an object's age or origin by looking at its composition.
Museum conservator David Hallum used X-ray fluorescence in the Museum Workshop exhibition to help document a silk and tulle dress worn by Lady Alice Carruthers on her presentation to Queen Alexandra at Buckingham Palace in 1908.
More on X-ray flurorescence and Lady Carruthers' dress
David also used the technique to identify the metallic make-up of threads and fabric in a Chinese processional costume from the 1880s, on loan from Bendigo’s Golden Dragon Museum for display in the Landmarks gallery.
Micro-fading
Hi-tech systems are also used to determine display periods for light sensitive objects. The National Museum has done extensive work on micro-fading to better understanding the fading characteristics of objects. This involves exposing objects to a very small pinpoint of infrared light. The results allow conservators to make more accurate predictions about the fading rate of objects if they are kept on display.
More on micro-fading in Nicki Smith's 'Risk management and light levels' audio presentation
Microscopes
Microscopes are used by conservators to identify materials and examine the structure of objects. Lower levels of magnification help to clarify features that can be seen with the naked eye. Under higher magnification, the fibres of paper become visible. In the case of a medal awarded to explorer Ludwig Leichhardt by London's Royal Geographical Society in 1847, surface characteristics not visible to the naked eye were revealed. Examination of objects under higher magnification requires careful interpretation. Scratches on a metal surface, for example, might result from the manufacturing process or alternatively be evidence of damage from vigorous polishing.
Debugging the collection
A very important aspect of preventive conservation work is the detection and elimination of insect and rodent activity. All items that come into the Museum's collection are inspected for pests and hazards, and all collection areas are continuously monitored. If there is evidence of insect activity or of the outbreak of mould, the Museum's preventive officer isolates the affected collection items and determines the appropriate treatment to eliminate the offending organisms, while keeping the ollection items intact.
Bad bugs
Insects can cause devastating damage to collections if not controlled.
Carpet beetles, borers, silverfish and case-making clothes moths can make a meal of museum objects, especially those made from fabric, paper, wood, feathers and leather.
Conservators treat infested objects, but they prefer to practise prevention by creating conditions that discourage insects from coming into the Museum in the first place.
Anoxic treatment
To treat insect infestation, objects are snap-frozen at –21°C or placed in an oxygen-free, or anoxic, chamber. The oxygen inside the chamber is replaced with nitrogen, causing the insects to suffocate. Anoxic treatment is used on objects that could be damaged if frozen, such as feathers, bone and electrical equipment.
Meet preventive officer Donna Wilks
A focus on preventing object damage
Donna Wilks had never considered a career in preventive conservation until she came to work in the conservation section at the National Museum.
Donna studied business management and completed a Certificate in Museum Practice. Her thorough attention to detail and enthusiasm for the work of the conservation team made her very well suited to taking on the role of preventive officer. Donna has not been through a formal training course in conservation but has had sound on-the-job training supplemented by specialised short courses.
Donna's work focuses on the prevention of damage to objects. On a day-to-day basis this means inspecting objects for any hazards or pest infestations, treating objects that are affected, inspecting storage and exhibition areas, supervising the cleaning of collection storage areas, monitoring environments and maintaining disaster bins.