Over the years, man keeps collecting objects of historical value. With these collections, he is able to learn about the past,enjoy in the present and helps give direction(s) on how the future will be shaped. For antiques to outlive man,he has to develop ways to preserve and safeguard them; so that generations yet unborn will enjoy and learn from them also.
Protecting antiques,monuments, historical sites,archival materials etc from damaging pests,man-made and natural disasters is a museum-wide endeavour. In this instance,we will discuss specifically the preservation of antiquities and other museum collections. Conservation starts immediately an object enters the museum; that is to say, all the operations of acquisition, entering in the inventory,recording in the catalogue, placing in storages/display, conservation processes and if necessary restoration. Conservation of objects is a shared role between the curators, documentation staffs,conservators,taxidermist.
The preservation of a museum collection and its associated data depends on a long term commitment to an ongoing conservation program. The primary goal of a museum object conservation program is to preserve whatever still exist of the object as nearly as possible to its original and in an unchanging state.
In museum practice, we have basically two types of conservation, which are :(1) Preventive conservation and (2) Restorative (curative) conservation.
1. PREVENTIVE CONSERVATION
Objects inevitably deteriorate over time. Preventive conservation seek to slow the rate of deterioration of material culture as much as possible. This effort is aimed at reducing the damage and deterioration to collections by improving the environment in which collections are kept. The parameters normally considered in preventive conservation of objects include:
(a) Temperature :Temperature is the degree of hotness or coldness of an object. Keeping collections in relatively low temperature environment helps to minimize the rate at which objects contracts and expand. When museum collections made of biological materials like wood,ivory,hide and skin etc contracts and expand quickly,it hasten the rate of deterioration of the object. Adapting a microclimate helps slows the rate at which pests develop and reproduce.
(b) Relative humidity (RH): RH is the ratio of the amount of water vapor actually present in the air to the greatest amount possible at that temperature. A RH reading 50% means the water vapor present represent only half the amount that will be present if the air were saturated at that temperature. Every material responds to their immediate environment. Very high RH is conducive for mould growth. Fluctuating RH causes organic materials like wood, ivory to undergo cycles of expansion and contraction leading to cracks, broken points and warping .RH of between 40% to 45% is most conducive for collections.
(c) Pollutants: particulate pollutants like dust,sand,grains and soot are carried into the museum from urban and agricultural environments. Sharp grains like sand leads to abrasion of object surfaces. Soot is grimy and acidic leading to discoloration, embroilment of organic materials and corrosion of metals overtime.
(d) Archival housing: for long term preservation, it is critical that objects housing physical support for objects are chemically stable materials that will not cause harm to the objects. Conservators study manufacturer’s data and conduct artificial aging and chemical test of materials to select materials for housing,storage and display mounts. The object structure and condition determines the support needed to prevent deterioration and breakage overtime.
(e) Loan documentation and packaging for transport: objects going on loan to other institutions are carefully examined to make sure they can safely travel and are packed to reduce the vibrations and shocks inherent in air and vehicular transport.
(f) Integrated pest management (IPM): protecting collections from damaging pests is very important. Pests like beetles,rodents,weevils, moths,reptiles,birds,should be kept at bay from objects.
(g) Hygiene and general house -cleaning: dust and debris in collection storage and workroom provide attractive environment for damaging pests. Dust falling on objects is often difficult to remove without disrupting the fine structure of materials like feathers and paint. Access to storage should be limited to reduce the build up and movement of dust and dirt’s. Workrooms should be regularly cleaned by housekeeping staff.
(h) Emergency/disaster mitigation and response: disaster planning includes identifying potential risks to collections, mitigating those risks through improvement to buildings, object storage/ support,exhibit furniture and procedures. Disaster maybe caused by natural events like flooding, tornadoes,earthquakes and by man-made situations like leaking pipes,breakage of vitrines and fire. When accidents occur, the Museum staff should respond immediately to reduce damage to collections.
(i) Handling: objects can suffer breakage and staining thorough inappropriate handling. All departmental staff, researchers, interns,and volunteers should be given training in lifting, supporting and transporting objects. Gloves are worn to prevent deposition of hand oils ,perspiration and soil. Padded carts with pneumatic wheels are used to move heavy objects
(j) Hazardous materials: these materials pose a great risk for staff working with collections. Some hazards maybe inherent in the objects themselves. For example, pigments made of arsenic or mercury materials. In other cases,toxins may have been applied to an object. In early effort to reduce damage. In museums in Europe, Asia and America, objects were tested for toxins and labeled if positive. Procedures have been developed in those countries with museum health,safety officers and public health advisors to protect staff.
2. CURATIVE (RESTORATIVE) CONSERVATION
This involves a direct interaction between the conservator and the cultural object (antique). It is also known as remedial, active and intervention conservation. Here ,the damage of the object has already occurred, before conservation work is introduced. It is very expensive to carry out. It has to do with the minimization of the deterioration process, restoring the object shape and form to near its original position and stopping further deterioration of the cultural object. This is only used when the existence of an object is threatened by damage or total loss.
Collections; either in storage, workrooms, galleries, halls etc should be made accessible and physical care must be of professional standard. Every treatment is an intervention, minimal treatment is preferred; this leaves an object closer to its original appearance, presents lesser risk and afford the opportunity to await a better treatment technology. The purpose of treating objects are:
● To stabilize the object for storage
● Clean the object for exhibition
● To repair after infestation
● To reverse previous treatments.
