THE DIFFERENCE BETWEEN
"POLISHING", "WAXING", AND "COMPOUNDING" YOUR VEHICLE
The whole concept of polishing the paint before applying any type of wax or sealer is to first clean out the pores of the paint and to smooth the surface until it is optically flat like the surface of a glass mirror. Even on round comers or curved fenders, every square inch of paint must be made optically flat. If you were to inspect a car's paint surface under a microscope it would not look flat at all. In fact it would look rough and have the appearance of deep crevices and high mountaintops. These are what are called high peaks and low valleys in the paint. High peaks are mused by paint overspray, bird droppings, tree sap, surface calcium deposits and dirt. Low valleys are pores containing dead oxidized material, sludge and dirt.
Just by looking at the surface with the naked eye, it is usually too difficult to tell just what degree of roughness from peaks and valleys are present. You can get a better feel for the condition of the vehicle's paint by running your hand across the Surface. Although you won't be able to tell everything by just running your fingers over the surface, a car that is well maintained should feel smooth, not dry. Generally, if the surface is not smooth or is hazy or dry, and doesn't bead water during the washing sequence, it is a sure candidate for polishing.
To achieve a plane of an optically flat surface, like that of a mirror you must first abrade or cut the paint. Think of smoothing paint as the same kind of concept when you are smoothing down a piece of furniture wood. First you abrade the wood by using rough textured sandpaper. Next you polish the wood again by using a lesser abrasive sandpaper. Lastly you do your final polishing and buffing; using a super fine sandpaper which leaves a silky smooth finish. The last stage for protecting the wood from water or temperature damage is to seal the wood by putting a protective layer of material over the bare wood or metal in the case of an automobile.
The same holds true for polishing the paint. You must first cut the paint in stages by using different levels of aggressive compound followed up by using lesser abrasive mild polishing products. Once this is achieved, the high peaks are removed from the surface and meet the plane of the surface and become one single flat piece of material. The low valleys in the paint remain until enough abrading is done to meet with the top surface just polished. The low valleys or pores of the paint hold the sludge, oxidation, and deeply embedded dirt, which are pulled to the surface by way of the chemical cleaners in the polish.
Compounding in its basic understanding in the use of, or aggressive act of, abrading severely damaged or dull paint. Compounding is going one step further than polishing, since this process requires a more aggressive cleaner to revitalize old dull and worn out paint. Compounding is what gives new life to traditional paint finishes, such as acrylics and enamels. Generally, paint that has become rough to the touch, either by means of paint overspray or an accumulation of environmental excretions, needs to be compounded. This process quickly and effectively levels the paint by smoothing the surface and removing dead oxidized paint. Compounding removes the upper most layer of oxidized material by actually stripping or cutting the first layer of paint. Compounds are created at different levels of aggressiveness.
The more course compounds contain a higher ratio of cleaning agents, usually between 12 to 15 percent. Larger particles of abrasive grit are used. The substance commonly found in heavier compounds is an abrasive product called silica. Silica compounds are combined with other chemical cleaning agents and lubricants to remove surface oxidation. You can usually judge the degree of abrasive ingredients in the compound by placing a dab of product in between your fingers. Again the concept of compounding is to cut out heavy oxidation and to level the paint to an equal plane.
A general rule of thumb: By Compounding should be a last resort to clear an old faded finish. Always test an area first with a milder polish or chemical cleaner. If good paint clarity is achieved with a lesser abrasive product, you will not have to strip as much of the paint, and in the long run the life of the paintjob will be greatly extended. If an aggressive compound is used, the paint should be renourished and sealed with a conditioner.
The compounding process dries and chafes a paint finish. Dry paint must be revitalized by adding back valuable conditioning oils found naturally in paint. Chafing the paint is very much like chafing or drying out your skin after shaving your face with a razor blade. As with compound, the razor blade removes a layer of protection. To prevent dryness to the newly exposed skin, a nourishing cream must be applied. Just as the surface of the skin has pores so does the painted surface of an automobile.
These exposed pores must receive nourishing oils to protect and condition the paint skin. Nourishing oils help to restore and brighten the color pigmentation in the paint and to slow down further oxidation by preventing evaporation and drying of the paint surface.