Old things, just like old people, need looking after if they are to survive. Objects that have lasted for centuries may not last much longer if they are not treated with care and respect and protected from the threats that can cause damage.
The following factors are important elements in what can be called “preventive conservation”. Not every factor applies equally to every type of antique, but, for a general collector, they all have a role to play.
Relative Humidity
This is a major factor that hastens decay and deterioration in all sorts of materials, whether in a compost heap or a museum. Relative humidity refers to the wetness or dryness of the air surrounding an object, there being a safe range within which deterioration is halted or slowed. Some items are very sensitive to humidity, such as books that can show “foxing” or brown marks when exposed to damp, or wooden items that can disintegrate if allowed to get too dry.
A hygrometer can be used to measure relative humidity, and the values adjusted by changing the temperature or by using a humidifier or dehumidifier to add or remove moisture from the atmosphere in which the antique items are kept. As well as the actual value of the relative humidity, sudden change is another destructive factor, so any such adjustments should be made with care.
In museums, relative humidity can be controlled item by item, if each is enclosed in its own glass cabinet. However, this is not so easy to achieve in the home, so it might be desirable to keep antiques that require different relative humidities in separate rooms.
Water
Direct contact with water can come about as the result of flooding, which would have most relevance to furniture items. If there is a risk of flooding to a room, such as in a house near a river, for example, valuable items can sometimes be mounted on blocks that would keep them raised above likely flood levels. Alternatively, keeping such items in upstairs rooms might be advisable.
Another problem is spillage on wooden furniture, resulting in bloom or ring marking. Prevention is definitely better than cure in such cases, so placing flower vases on top of valuable pieces, for example, is to be avoided.
If water is to be used when cleaning an item, it is best to test the effects in an inconspicuous area before proceeding further, because water can dissolve adhesives, dyes, paints, etc.
Light
Excessive light can damage antique items, such as furniture or paintings, by causing fading or colour changes. It can also lead to deterioration in fabric items such as clothing, tapestries or book bindings. The damage is caused by the brightness or intensity of the light, such as through south-facing windows (in the Northern Hemisphere) and also by ultraviolet light, which cannot be seen but is just as destructive.
A lux meter can be used to measure the absolute amount of light entering a room, with this being controlled by the use of filters, dimmers, and so on. The positioning of light sources in a room is also important, so that bright light does not fall directly on to the objects. Ultraviolet light can be controlled by avoiding the use of fluorescent lighting, although sunlight also has a high UV content.
Insects
and mould
Organic materials are excellent insect food and also for the growth of moulds, if the conditions are right. Moths do not damage fabrics, but their larvae do. Likewise, the larvae of the furniture beetle, commonly known as woodworm, make no distinction between floorboards and valuable pieces of Chippendale. Other pests include the carpet beetle and fur beetle and, in some parts of the world, termites.
Getting the relative humidity right, and making sure that ventilation is adequate, should prevent moulds and fungal growths forming. If there is a problem, the important thing is to dry out the atmosphere gradually and increase the level of ventilation. Fungicides should be used with care.
Insecticides should be used with great care, as they can also cause damage to the items you are trying to protect. It is better to examine objects carefully and regularly for signs of attack and deal with small problems rather than large ones.
Heat
As well as its role in relative humidity, mentioned above, excessive heat or cold can have a direct impact on antique objects, and should be avoided. For example, resins and waxes can melt, and paint can blister.
Dust
and pollution
Keeping antiques dust free is not only important aesthetically but also in terms of preventing deterioration, because dust can attract moisture and chemical pollutants such as sulphides that tarnish silver and also form sulphuric acid. Dust can also act as an abrasive that weakens textile fibres.
The use of dust sheets and plastic coverings can prevent dust from reaching valuable objects, although this makes it less easy to appreciate the beauty of one’s antiques! Acid-free tissues can be used to advantage when cleaning.
Abrasion
and over-cleaning
Despite the above note about the value of keeping items dust-free, it is also possible to overdo the cleaning and polishing of antique items. For example, the value of a piece of silver will be greatly reduced if the hallmarks are rendered unreadable by over-zealous polishing, and the loss of fine detail will in any case detract from the appeal of the item as a whole.
The use of abrasive cleaning materials can cause scratching, and, for many antique items, the patina of dirt acquired over centuries is part of their attractiveness and should not be removed.
Cleaning must therefore be done with great care, only using mild cleaning agents and gentle pressure. The whole point of owning an antique object is that it does NOT look like new!
Handling
and storage
The more that fragile items such as glass or porcelain are moved or handled, the greater their chance or being dropped. Excessive handling can also cause finger-marks which could in turn attract mould. The leather bindings of books can be damaged when pulled from a shelf, and ancient manuscripts should only be touched when wearing soft gloves.
Likewise, an antique’s safety may depend on how secure the surface is on which it is displayed. The top of a wobbly bookcase is probably not the best place for your priceless Ming vase!
Items in storage are also not safe from deterioration if the conditions of storage are incorrect. For example, an attic is quite likely to suffer from extremes of heat and cold or to be damp. Materials in which items are wrapped can also have an adverse effect, as such things as newspaper or foam rubber can release harmful chemicals when they deteriorate.
With all these factors to bear in mind, it sounds as though collecting antiques is an activity that is fraught with peril! However, the responsible collector appreciates that he or she holds these items on trust for future generations, and has a duty to posterity to ensure that they are preserved as carefully as possible.
That said, the above precautions should not be too arduous to take, and, as said earlier, not every hazard applies to every type of antique. It does, however, behove the collector to be aware of the threats that apply to the objects he or she wishes to collect, and to act accordingly.
© John Welford
No comments:
Post a Comment