Outdoor Collections

If damage has occurred, what should and shouldn't be done?

There has been a lot of discussion recently about the appearance of outdoor cultural material. This discussion has focused particularly on bronze sculpture, but is equally valid for all outdoor artefacts.

It is only natural that outdoor materials will deteriorate, simply because they are located in a harsh environment; and in many ways this deterioration is a significant part of their history. If treatment gives them an as new appearance, this visual history will be lost. In some cases this may be valid, for example, if the deterioration is threatening the existence of the object. However, in most cases it will be a matter of:

• consulting with the relevant people, that is, conservators, custodians, historians and the artist;

• weighing up a number of factors, such as the artist's intention, the relationship between the item and its site, and the historic or cultural significance of the piece; and

• taking into account the ethics of the conservation treatment.

These general guidelines are provided to help you if you have a damaged piece of outdoor cultural material.

If part of an item has broken off, collect all the pieces, wrap each piece separately and place the pieces in a clearly labelled box. Contact a conservator as soon as possible. Because the other half of the break is in an outdoor setting, it is best that the repair is done as soon as possible before the edges are worn by weathering, or before more damage occurs.

Do not repair stone with concrete. These repairs are usually unattractive; but they can also be damaging because the concrete can be harder than the stone. If this is the case, future cracks form in the stone, not in the concrete.

Heritage items should not be repainted. The original paintwork is an integral part of these items and can be damaged and destroyed by repainting. Consult a conservator if you feel that repainting is important for the future survival of any painted items.

Beware of replacing components of a heritage item to 'pretty it up'. It is often tempting to replace worn or damaged components, especially where the skills and technology are readily available; but you must be aware that it may interfere with the historic value of the item. Remember, an historic artefact is only as historic as the sum of its components. Consult a conservator if you are unsure about whether to replace components.

Avoid using sand-blasting and steam-cleaning to treat historic artefacts. While there are occasions when an air-abrasive technique will be necessary to treat an item, sand-blasting is generally considered to be too abrasive. It causes loss of surface detail and pitting of the surface, which in metal objects can lead to accelerated corrosion. Steam-cleaning is often used on stone and it is also too harsh. It can cause loss of detail on delicate, stone surfaces.

If you need to use metal fixtures with metal outdoor objects, wherever possible use fixtures of the same metal as the structure to be secured. In this way you can avoid the problems of galvanic corrosion. If you cannot use the same metal, place an inert barrier layer between the two different metals.

Some outdoor sculpture is intended to deteriorate. Unless there is a public safety issue involved, these objects should be left alone to deteriorate slowly. Any work that must be done on the piece should always be carried out in consultation with the artist, if the artist is alive and accessible.