Automobile restoration is the process of repairing a car to return it to essentially the same or better condition than it was in when it left the factory at time of manufacture. It should include not only repair of the parts that can be seen – the body, the trim, the chrome, the wheels, the dash board and accessories and the passenger’s compartment – but the parts that are not necessarily visible or otherwise evident, including the engine and the engine compartment, the Trunk (automobile), the frame, the driveline, and all ancillary parts like the brakes, accessories, engine cooling system, electrical system, etc. Besides repairs done to correct obvious problems, repairs are also done for cosmetic reasons. For example, even if a wheel is covered by a hub cap and not seen, and is structurally sound, it should have the tire unmounted, then any required repairs such as rust removal, straightening, priming and painting.
A complete auto restoration should include total removal of the body, engine, driveline components and related parts from the car, total disassembly, cleaning and repairing of each of the major parts and its components, replacing broken, damaged or worn parts and complete re-assembly and testing. Each and every part should be thoroughly examined, and either cleaned and repaired, or if repair of the individual part would be too costly, replaced (assuming correct, quality parts are available). All of the parts showing excess wear or damage that were originally painted should be completely stripped of old paint, any rust or rust related damage repaired, dents and ripples removed and then the metal refinished, primed and painted with colors to match the original factory colors. Wooden parts should go through the same meticulous inspection and repair process with regluing, replacement of rotted or termite-damaged wood, sealing and refinishing to match the factory specifications. Chrome and trim may require stripping and repair/refinishing. The frame must be thoroughly cleaned and repaired if necessary. Often sand-blasting of the frame is the most expeditious method of cleaning. The frame should be painted or powder-coated to match the original. An idea of the sort of work that must be undertaken can be viewed here .
The Interior of the car should be stripped of the old upholstery and carpeting and it should be replaced with new parts, again, to match those that were available from the factory. See here . The seats should be repaired before being reupholstered and the coil springs repaired, replaced or retied. The instrument panel, or dash board contains a number of gauges, each of which have to be repaired and brought back to both operational and cosmetic standards.
The repair and refinishing of the car's body and frame should include repairing, straightening, priming, and painting of the panels as well as the frame (for cars that are body-on-frame and not unibody).
Repair of the car's frame is important since this is the foundation for the entire car. The frame must be inspected for straightness, twisting, alignment, rust damage, and condition of the mounting points for the body, suspension, and other components. Any problems must be repaired, which can be a costly process. For many popular cars, replacement frames can be purchased from parts suppliers specializing in that make of vehicle. This is often a better option than investing money into a severely damaged frame. Depending on the frame construction, mud and water can make their way inside the frame and cause rusting from the inside out, providing additional reason to consider a replacement frame.
If rust is present on a body panel, the panel was damaged by a collision, or other damage is present, there are several options for repair: fix the damaged panel (minor damage), replacement (excessively damaged panels), or cutting out and replacing a portion of the panel (moderate damage - for many makes of vintage car, small partial patch panels are available and designed to be welded into place after the damaged portions are cut out). Although, this may seem simple in principle, in practice it is highly skilled work. One of the highest skills in restoration is the use of the English Wheel or Wheeling Machine. Many panels, (especially if from different sources), may be a problem to fit together and need reshaping to fit properly. Variation in panel size and shape and 'fettling' by skilled metalworkers on the factory production line to make panels fit well, used to be common practice, especially with British and Italian sports cars. Even genuine New Old Stock factory panels may require panel beating skills to fit. Re-installation of the repaired and repainted panels will require that the panels be installed and then aligned so the gaps between panels are correct, the doors, hood, and trunk open and close properly, and there is no interference or rubbing. It is best to trial fit before painting and do any metalwork adjustments that are necessary.
Once the panels have been repaired, they should be primed and painted a correct historical color for the vehicle (although this is debatable - the owner might want to have the car painted to look like a particular specialty vehicle such as a police car, or a delivery van painted to look like it would have in grandfather's company colors, etc.)
Individual painting of the panels is generally the correct approach, as this will result in all parts of the panel being painted as opposed to partially re-assembling and then painting, leaving parts of the assembly that are touching or "blind" unpainted. The separate painting approach should also result in no overspray on other parts of the since they will not be on the car at that point.
It is important to consider the colors and treatments applied to the panels, from the factory. Sometimes the car's owner may wish to have a panel or portion of the car entirely painted when in fact it may have come from the factory with undercoating or other coating applied to one side, which may be less attractive than a smoothly finished and painted panel. In other cases, the owner might paint or plate a collection of small parts to look similar for a better appearance, when the factory might have installed these as many different colors since the factory's prime concern was function and not appearance. Depending on the level of restoration the owner had undertaken, he or she may want the car to be EXACTLY as it left the factory. If the owner is going for a less exact restoration (which could have benefits in terms of appearance but reduce the cars likelihood of winning concours-type shows) then he or she may choose to deviate from the car's original factory appearance.
The entire Engine and all related systems should be rebuilt. The engine and all of the ancillary components – starter, generator/alternator, radiator, distributor, carburetor and all others – should be removed and rebuilt to factory specifications. The engine itself, plus the transmission, clutch, overdrive unit and even the driveshaft should be completely disassembled, cleaned and measured for wear. This will show up as deviation from original factory specifications. All of the fixed parts – block, crankcase, head, transmission housing, etc. – should be inspected for cracks or other damage. All moving parts – pistons, crankshaft, camshaft, oil pump, bearing and bushings, flywheel, water pump and all others – must be cleaned and measured against factory specifications and, if necessary, machined or re-manufactured to bring them within specifications. The same goes for the transmission, clutch, differential and all other moving parts of the power line and drive line. All of the electrical system has to be inspected and, if it shows wear or damage, replaced. Then the entire engine/driveline will have to be reassembled, replacing all worn bearing and bushings, seals, gaskets, belts and gears.
Finally, the engine/driveline has to be re-installed in the frame, the brakes, wheels and other parts re-installed, the body fitted to the frame and the entire car rechecked and tested. Restoration of a car is a daunting task, not one to be undertaken lightly, or by the inexperienced. A full restoration can take many years and can cost thousands of dollars; often, and generally, well in excess of what the finished value of the car will be. Many jobs will have to be farmed out to specialty shops; those with the special knowledge and equipment to do the job. Often a restoration once started is left unfinished and the car and parts can be purchased for a fraction of their worth. But if a person buys an unfinished project, it is imperative to be sure that all of the parts are there. Finding parts for an orphan or rare car can be near impossible. There are different levels of automotive restoration. The highest quality level, generally unobtainable for the amateur restorer, is the Concours d'Elegance level; these are cars that are restored to a degree often beyond the quality that they were when they left the factory. There are virtually no deficiencies in the quality of the restoration. Many Concours d’Elegance cars are not driven except for the short distances from their trailers to the show field.
The lowest level of restoration is that of just getting the vehicle to run, with little or no regard for appearance or quality.
Between these two extremes are the vast bulk of cars that are seen as drivers, neighborhood show cars, 20-footers (they look great from 20 feet away). Many value guides offer six levels of quality, from a ‘parts-only’ car to a Number 1- absolutely perfect in every way. For the amateur, or even experienced restorer, there are a great number of help sources, books and magazines to assist with restoration of an entire car or specific parts. There are also enthusast websites that can offer help advice and contacts for vehicle restoration such as bugme.co.uk, relating to the restoration of a 1964 Volkswagen Beetle 
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