Automotive restoration can be applied to many different eras of the automobile. Heritage railways and railway museums aim to restore and operate restored trains. Bus preservation groups aim to purchase buses of various eras to restore them to their original operating condition. Trains and buses are often restored to the original authentic livery of their original owner.
Restoration of a vehicle refers to the process of restoring a vehicle to its original condition. Neither updating nor modifying are considered part of the restoration process. A restored car is one that has had all of its systems and/or parts restored to original condition. Selectively restoring parts or systems is referred to as refurbishing. It does not qualify as restoration. Rebuilding an engine may restore that engine, but it does not restore the car, or entitle the car to be called a restoration.
A car that has had its body work restored to as new condition but has undergone some modifications elsewhere is either a modified car or a resto-mod car, neither being completely restored nor completely modified. If a car has had an engine swap for other than the original model, that car has not been restored. Although most of the parts are original, it qualifies as modified rather than restored.
There are many aspects to the process of vehicle restoration. The goal is to return the vehicle to its 'original' state. To accomplish this, a vehicle must often undergo many structural and aesthetic changes.
The first project is disassembly. The car is taken apart and the chassis is inspected. The chassis must be in order as it is the structural foundation of the vehicle. The next tasks are typically the vehicle's engine and mechanisms. The restorer will mechanically bring the vehicle into working order before aesthetically restoring the interior and exterior of the vehicle. Once the vehicle is mechanically functional the body work is then done to the car. Once the exterior restoration is completed, the last task is the interior finish. The restoration of the car is complete when the interior restoration is completed.
Interior restoration is the process of returning the inside of the vehicle to its original factory state. Often a vehicle's interior must be need to be completely stripped out before restoration can occur. This is because deterioration over time that can leave materials like wood, cloth or leather in unusable condition. Also abandoned vehicles have the potential to contain biohazardous material within the cabin caused by decay and habitation by animals. Often seating will be stripped to the wire framing before being stuffed and upholstered. The seat is still considered to be authentic after undergoing this process. Other areas of interior restoration include replaced instrument paneling, car radios, flooring and wooden paneling
All mechanical and electronic equipment such as a speedometer, gas gauge, air bags and other equipment necessary to the safe operation of the vehicle must be inspected. The vehicle interior is considered restored when it is returned the state of function and aesthetic the car was in after its manufacture
Restoration of a vehicle's exterior can take many forms. A vehicle that has been left or abandoned will often accumulate rust over time. Sometimes this rust deterioration can render an exterior part unusable. In which case a replacement part like a fender, front grill or door mirror must be purchased outright from an external source. If rust damage is minor however the part will undergo rust repair. This is the process of removing rust from metal and returning structural integrity. This is accomplished by removing the rust through sanding or blasting to get down to bare metal. Then new sheet metal or fiberglass is applied to the affected area. Finally the piece is worked until smooth, primed and re-painted.
Other materials like glass and weather stripping must be replaced as they become damaged over time. Factors like weather erosion can lead to faded and broken glass as well as dried out weather stripping. Another typical area of exterior repair is dent removal. This entails taking the original metal and re-working it to remove dents and other such blemishes. Professionals often use hammer and dolly work to remove dents. This involves placing the dented metal piece over a curved metal dolly and using an electric or manual hammer to remove the dent and smooth the metal. Often, vehicles require plastic headlight restoration as headlights can become foggy over time due to weathering.
The internal combustion engine requires regular maintenance to ensure its continued function.Engine oil, power steering and brake fluid are examples of engine maintenance that must be kept and checked at regular intervals. Often wear and tear over time can leave an engine totally unusable, in which case the restorer might remove the existing engine and replace it with a similar or modern engine substitute. In order to conduct an engine restoration first a technician will conduct a thorough inspection. Often pre-restored vehicle have engines that have gone without maintenance for years and therefore require engine restoration to return them to working order. The engine is removed from the car and inspected for broken and non-functional parts. Typical parts that require replacing include the pistons, spark plugs, fuel lines battery, fuses, timing belt and various gaskets. All are subject to deterioration over time. Structural components like the engine block, cam shaft and crank shaft are less likely to require repair but not uncommon. Typically, after all required parts are gathered, the disassembled pieces will be cleaned, lubricated (if required), and reassembled. The engine is then replaced within the car.
A mechanic will then perform a series of tests to ensure that the engine is in working, road worthy condition. This is known as a pre-start engine check. First all the lines and hoses are checked for breaks and leaks. Second the radiator is topped off with water to ensure that the system is sealed off. Next the oil level is replenished. Finally the battery charge is checked and the ignition system is inspected. The engine is then ready to be started.
Vehicle conservation refers more broadly to the conservation of very old vehicles for the purposes of preserving history, rather than transportation. A mechanic can provide specific instructions on which chemicals to use on older paints and metals in order to preserve the integrity of the frame.