Caring for vehicles

Recommendations

• Insert supports under axles and other load-bearing members of vehicles with wooden wheels or rubber tires. Wheels should be just slightly off the ground (Figures 4a, 4b, 5 and 6).

• Raise vehicles and rotate wheels regularly if no axle stands are present.
• Store vehicles on a firm and flat surface, such as a level concrete floor. Use rubber mats to prevent abrasion between the wheels and the floor.
• Custom build supports for unstable or fragile objects (Figure 7).

For more preservation strategies to deal with physical forces, consult Agent of deterioration: physical forces.

Recommendations

• Prevent harm due to unauthorized access with temporary pedestrian barriers that cannot be moved easily. Several kinds are available, e.g. braided or velvet ropes or retractable belts on metal stanchions. Permanent barriers such as metal railings or floor edging resist being moved by the public but are also more expensive and less versatile (Figures 8a and 8b).

Figures 8a and 8b. Effective pedestrian barriers can be integrated into a display, as shown in these two examples from the Remington Carriage Museum. Left: Hearse carriage manufactured circa 1900. Right: Menard Auto Buggy manufactured circa 1908.

• Install a psychological barrier, such as a raised curb or wooden strip along the edge of the walkway to alert visitors to the inviolability of the space beyond (Figure 9).

• Install signs instructing visitors not to touch the objects (Figure 10).

• Assess small movable or easily breakable parts (glass dials, etc.) in terms of their vulnerability to theft and vandalism, and implement a means of protection, if warranted. Several levels of deterrence are possible. For example, install temporary protective barriers such as a Plexiglas screen. Using security screws (requiring special tools or procedures for removal) is another option. Before altering any original parts, consult a conservator for guidance.
• Prevent the deposition of corrosive fingerprints on bare metal surfaces with barriers and other deterrents (see above).
• Treat bare metal surfaces with transparent, non-tacky rust-preventive coatings or microcrystalline wax.
• Use proximity alarms with loud sounds to deter visitors from approaching items.
• Install a remote security system, including motion detectors, silent alarms and video surveillance, as required. These measures are most useful during closing hours and only helpful during opening hours if there is vigilance and immediate staff response.
• Full-time security guards or guides who accompany visitors may prove more effective than an alarm system.

For more preservation strategies on these topics, consult CCI Note 15/4 Indoor Display of Industrial Collections. Consult also Agent of deterioration: thieves and vandals and Caring for metal objects.

Recommendations

• Dust properly and regularly to prevent abrasive scratching of polished or painted surfaces (Figure 1c). This must be done by trained, conscientious staff.
• Once the surfaces have been dusted, use dust covers to protect vehicles in storage (Figure 11).
• Eliminate sources of dust, e.g. by installing carpets at the entrance of the building, by paving entrances and by sealing concrete floors and walls.
• Consider applying protective coatings such as microcrystalline wax to protect bare metal surfaces, as further discussed in CCI Note 15/4 Indoor Display of Industrial Collections.

For more preservation strategies to prevent dust deposition, consult Agent of deterioration: pollutants (under the "Fine particles" subsection).

Temperature

Cooler temperatures will reduce corrosion rates and chemical degradation rates for sensitive materials such as rubber and plastic. In fact, lowering the temperature by a mere 5 °C cuts their degradation rate by half. On the other hand, reduced heating can lead to increased RH if there are no dehumidification controls in place, and high RH increases the metal corrosion rate. Overall, the best strategy is to keep temperatures as low as possible, but only to the extent that it is also possible to keep the RH below 70%.

For more preservation strategies related to managing temperature, consult Agent of deterioration: incorrect temperature.

Relative humidity

Preservation strategies for controlling the RH that are tailored to vehicles usually involve finding the best compromise solution between the needs of the vehicle's metal parts and those of the organic components (wood, upholstery, rubber, plastic).

Recommendations

• Keep RH below 70% to prevent rapid corrosion and to prevent the swelling of wooden joints such as wheel spokes, which loosen upon return to moderate RH. Among the risks associated with incorrect RH, damp is the most important to vehicle collections.
• If vehicles contain complex wooden items and assemblies, or restrained leather such as canopies, keep RH above 30%, especially if they have never been in heated buildings before. (This 30–70% RH range is Level C in the ASHRAE nomenclature (the American Society of Heating, Refrigerating and Air-Conditioning Engineers); consult Environmental Guidelines for Museums.)
• Note that if the entire collection has already been exposed to very low RH many times over the years (e.g. during winter in a heated building, the RH can become very low) and there has not been any remedial treatment (no repairs of cracks and tears or refinishing of old coatings), then the risk of new fractures from low RH is reduced. These periods of low RH can prove beneficial, since dry air slows down the process of corrosion.
• Metal surfaces that may have been exposed to calcium chloride salts (used to control dust on gravel roads or as an antifreeze in the water added to agricultural tractor tires as a ballast) should be cleaned since these dusts and contaminants accelerate corrosion at any RH above 33% (worse than the salt used for melting snow, which accelerates corrosion when RH is above 75%). Contact a conservator for advice on cleaning delicate surfaces.
• Protect bare metal surfaces with transparent, non-tacky rust-preventive coatings (e.g. microcrystalline wax). It is especially important to protect bright surfaces of base metals (iron, steel, copper, bronze, brass), particularly if they were either sliding surfaces or kept polished during original use. Even at moderate RH, these uncoated surfaces will corrode (tarnish) in a few years, especially if they are exposed to the ambient air rather than protected by a tarp or dust cover, or in an enclosure. If left to accumulate, dust and lint will aggravate corrosion problems.
• Consider humidistatically controlled heating for large vehicle storage buildings, especially in central Canadian climates. Consult Agent of deterioration: incorrect relative humidity – Vignette 3 for an example of such storage climate management.

For more preservation strategies related to managing RH, consult Agent of deterioration: incorrect relative humidity, Caring for metal objects and Furniture and objects made of wood.