Keeping Models Shipshape

The National Maritime Museum exhibition Modelmania demonstrates just how many different sorts of ship models there are, and the wide variety of uses for which they are built. Conservator Stephen Jackson, who works on the Museum's models and prepared many for the exhibition, confirms that prevention of problems on these small craft is always better than the cure.

Ship models are among the most delicate artefacts a private collector can acquire. Their fragile construction, protruding rigging and their attractiveness to children (of all ages) leave them very prone to damage.  In the past, ship model collectors were also often model makers. Contemporary enthusiasts may not have the 'old salts' familiarity with ships or boats, and may lack their skills, knowledge and tools for maintenance and repairs.

By far the easiest way to avoid accidental damage is to display and store a model in its case. If it does not have one, a case sympathetic to the model's appearance can be constructed at relatively low cost. Cases should never be constructed from untreated wood products, particularly chipboard, MDF or plywood. Coated solid woods and metals are better. Charcoal cloth in the model case will reduce the levels of gaseous pollutants and minimise the risk of deterioration.

Washing your hands before touching a model will prevent the transfer of damaging amino acids, moisture or salts from the skin. Always question if it's necessary lo handle the model. When viewing, can you walk around it instead?

Fluctuations in temperature and relative humidity (RH) can cause many problems. High temperatures can lead to desiccation of organic components such as timber and paper or can cause physical damage if differential expansion of the materials occurs. Deterioration processes such as oxidation are accelerated by increased temperature. In the opposite extreme,  freezing can damage.

High RH can encourage the growth of fungi, cause swelling of moisture absorbent materials, condensation and a host of other problems. Low RH can lead to shrinkage and the embrittlement of some organic materials. Attempts should be made to avoid environmental extremes by storing or displaying models in reasonably stable areas.

Avoid storage or display in basement areas with poor ventilation and damp. External walls can be prone to condensation and west-facing walls can also be a source of fluctuating and high temperatures. Storing models [Pullout:Marine models come in all shapes and sizes. This clock, made in Paris in 1890, may well have been presented to a ship's captain or builder as a gift for service. The helmsman is connected to the pendulum and sways from side to side. Marine clock, made in Paris in 1890.] in an archival quality box will help to buffer them against environmental changes.

Light can seriously discolour and weaken a wide variety of materials such as dyes and pigments, cellulosic materials like wood or cotton or proteinaceous materials like leather and wool. The amount of deterioration is proportional to both the light level and the length of exposure. For example, if the light level on a model is doubled, the same amount of deterioration will occur in half the time. The most harmful forms of light are direct sunlight and fluorescent lights.

Avoid storing or displaying close to windows, fluorescent lights or on west facing walls that get a  lot of sunlight. If you wish to spotlight a model, use a low wattage incandescent light bulb and limit the length of time it is turned on.

Insects and pests can cause a great deal of damage. They may eat materials, mark them by leaving droppings and regurgitated matter, bore into organic matter, make nests and so on. Insects and pests often thrive in environments with high RH or temperature and in poorly cleaned areas. Models and their surroundings should be kept clean and separate from food areas. Regular inspections of the storage or [Pullout:Using scrap timber, cigarete tins, and discarded wire to fashion hull, sails, wheel and companionway, the ship's carpenter made this model of the 'Derwent', the ship on which he was sailing, c 1900. Model of the 'Derwent' c. 1900.] display areas are important. Avoid storing objects in damp and cluttered spaces. If insect infestation occurs, a profesional conservator should be consulted as soon as possible.

Pollutants such as dust and dirt can form an unsightly surface film and encourage fungal growth and insect attack. Particles can adhere to varnish and paint surfaces or become entangled in the fibres of textiles, requiring complex methods of cleaning that can be harmful and expensive. A well-fitted case and good house keeping will eliminate such problems.

The woods, glues and paints often used in model construction can form harmful vapours such as organic acids and formaldehydes. In the enclosed environment of a model case these substances can become quite concentrated and seriously damage the chemical structure of materials such as wood, paper, textiles, ivory, bone, and especially metals. Gaseous pollutants from industry such as sulphur dioxide, nitrogen dioxide and ozone can also seriously degrade many materials.

Under some conditions fungi will attack organic materials such as wood, paper and cotton. The type and degree of deterioration will [Pullout:Made from kitchen scraps - cattle bones - that were cleaned and rubbed with beeswax, these now world famous models were the work of French sailors captured during the Napoleonic Wars. This particular one, in the collection of the Australian National Maritime Museum, was constructed c.1790. Model constructed from ship's scraps, c.1790.] vary greatly, ranging from slight discolouration to total destruction. Fungi will only germinate, grow and produce spores when the RH is higher than 60%. By maintaining RH levels below this, fungal attack can be avoided.

Storage and display areas should be kept well ventilated and maintained free from dust and dirt. Inspect items regularly for evidence of mould attack. If an attack is noticed, the model should be moved to a dry environment and a conservator should be called for advice regarding treatment.

Consideration should be given to the susceptibility of the model to loss or damage by theft, fire and flood. Valuable models should be documented, photographed and insured where possible.