Polishing will add more shine to your paint than any other step in the detailing process. Basically, polishing will level your paint by thinning the paint a small amount. The now flat surface will appear much glossier and wetter than prior to polishing.
Polishing will also remove defects from the paint such as scratches, swirls, water spots, etc. The polish accomplishes this by removing paint until the surface is level with the lowest point of the defect thus establishing a flat surface. Keep in mind that while all defects can be removed through the use of a polish not all defects should be removed. Some defects such as the scratch pictured farthest right in the below diagram are very deep. Bringing the surface level of the paint to the lowest level of the defect would leave little to no clear coat on the car.
A good rule of thumb to follow is that if a scratch catches your fingernail then it’s likely too deep to remove. Polishing the scratched area is still recommended. However, do so with the idea that you are attempting to make the defect less noticeable and not trying to remove it.
Unfortunately, the term “polish” is not used in the same way universally across all car care brands. So, be sure to check the definition of the term “polish” in the glossary.
There are two ways to apply polish: by hand and by machine.
While you can polish a car by hand effectively with a product designed for hand application like Meguiar’s Scratch-X, defect removal is a very labor intensive process when done by hand. Additionally, polishing by hand is less effective and may only remove a defect 80% while machine polishing may remove 90%-100% of the defect.
Polishing by machine is the most effective and time efficient method. Machine polishing will remove more defects than hand polishing is capable of performing due to the amount of heat the machine can develop due to friction.
There are two types of polishing machine: the random orbit polisher and the rotary buffer.
The pad on a random orbit (R/O) a/k/a “dual action” polisher not only spins on an axis but also jiggles around the axis. This results in the pad not remaining in the same spot for too long and therefore there is less chance for heat to build up. This makes the R/O slower at removing paint, but also safer and easier to use. The R/O is a very easy to learn machine and people with little experience can become skilled quickly. The most popular and most versatile of the R/O polishers is the Porter Cable 7336SP/7424/G100. The PC is more powerful and more versatile than other less expensive R/Os and therefore the most popular.
The pad on a rotary buffer simply spins in a circle around an axis. This creates a great deal of heat through friction and therefore removes paint faster than the R/O. The rotary buffer removes defects faster and more efficiently than the R/O. However, in untrained hands the rotary can burn paint or create buffer trails in the paint.
There are two types of polish available: abrasive and chemical.
Abrasive polishes work similar to sand paper by scouring the paint mechanically. Also like sand paper, abrasive polishes come in different levels of abrasiveness. These abrasive levels are often referred to using various terms such as compound, finishing polish, and medium cut polish. Most modern abrasive polishes feature diminishing abrasive particles which break down during use to prevent excessive amounts of paint removal and to leave the paint surface as smooth as possible. It is often necessary in order to get the best result to “step down” polishes. This involves starting with a more abrasive polish to remove paint defects and then to polish the car again with a finishing polish to “jewel” the finish and to remove any remaining fine defects. Abrasive polishes work best for removing paint defects, but also can remove oxidized paint.
Chemical polishes contain no abrasives at all and work similar to a solvent by chemically dissolving oxidized paint. Typically a chemical polish excels at removing oxidized paint (and also polishing metal) because it is formulated to chemically break down and remove the oxidation. Chemical polishes are often referred to as “paint cleaners” or “pre-wax cleaners.” They are excellent for use on oxidized finishes and for simply removing old wax. Chemical polishes can be used to remove paint defects but are less effective than abrasive polishes because the chemical polish completely depends on the abrasiveness of the foam pad to remove the paint around the defect. Chemical polishes are best used on paint with little to no defects.
It is important to note that the amount of abrasion the polishing process has is a product of the combined abrasiveness of the pad and the polish.
It will vary based on several factors, but you should not need to polish your car’s paint more than 2-3 times per year. You may need to “spot polish” on occasion to remove defects which are only found in a small area of the paint. Keep in mind when you are polishing that you are removing paint. If you penetrate the clear coat then your car will need to be repainted.
What you’ll need . . .
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Shade – Most polishes are not designed to be used in direct sunlight. Therefore, it is important to find a shady spot to work in. This can be under a car port, a canopy, or in a garage. It is not recommended that you detail under a tree as sap, leaves, pollen, or other debris could fall on your car during the detail.
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Tarp – when machine polishing it is common to have polish spray from the pad onto other parts of the car. In order to minimize clean up, it is highly suggested that you cover your convertible top with either a plastic tarp or an old bed sheet. -
Porter Cable R/O polisher – Either model G100, 7424, or 7336SP work well. In fact, all three models are virtually the same machine. The only difference is the counterweight and most cannot tell the difference between the two. The 7424 and G100 come with a 5” counterweight and the 7336SP comes with a 6” counterweight. -
5”-6” backing plate – You’ll need an appropriate size backing plate to mate the PC with the foam pads. The diameter of the backing plate should be at least ” less than the diameter of the pads being used to prevent the backing plate from touching the car. -
6.5” foam buffer pads – A variety of pads may be needed to polish your paint. It’s best to have on hand at least (1) cutting pad, (1) light cutting pad, (2) polishing pads, and (1) finishing pad. If you have at least these pads you should be equipped to handle most paint conditions.
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Polish – Depending on the condition of your paint you may need to use 1-2 different levels of polish. You will certainly need a finishing polish (ex. Menzerna FPII or Poorboy’s SSR1), but there may also be a need for a medium cut (ex. Menzerna Intensive Polish or Poorboy’s SSR2.5) or heavy cut polish (ex. Menzerna Power Gloss or Poorboy’s SSR3). The more aggressive the polish the more severe paint imperfections it will be able to remove. If the paint has little to no defects try a chemical polish like Poorboy’s Pro Polish. -
Microfiber towels – high quality microfiber towels are critical for polish residue removal. After a long day detailing you don’t want to use a cheap towel which will undo all of your hard work by instilling scratches in your paint. To test the “softness” of a microfiber simply rub it gently on a blank CD making sure to use both the center of the towel and the edging. If the towel leaves scratches then it could possibly scratch your paint. Always be sure before testing a new towel or using it on your paint that it is clean and that any tags have been removed. One last item to note is that microfiber towels with a shorter knap will remove polish residue faster than towels with a deeper knap, but will also clog with residue faster.
How to get it done . . .
1. Before beginning to polish make sure the car is completely clean and dry. Always wash or QD a car immediately before polishing. The car cannot be driven in between washing and polishing.
2. Cover as much of the convertible top as possible with your plastic tarp or old bed sheet.
3. Begin by testing combinations of pads and polishes on an inconspicuous area of the car (see steps 4-10 for polish use instructions). If the paint is simply lacking some gloss then a finishing polish and a polishing pad may do the trick. Start with this combination and work down toward your most aggressive combination (heavy cut polish with a cutting pad) until you find the polish/pad combination which will remove the defects from your paint. Be sure to use a strong light or even sunlight to check the test results.
4. Once you have found the polish & pad combination which will remove the defects in the paint, you will need to polish the rest of the car. Apply a ring of the polish to the foam pad along the outer edge of the pad’s bottom.
5. With the machine turned off, spread the polish onto your working area. Your working area will consist of a 16” x 16” section of paint preferably bordered by a character line or panel gap.
6. Turn the PC speed dial to setting five (you can also use speed 6, but keep a careful eye on your foam pad as heat may build up causing the Velcro backing to delaminate).
7. With the pad flat against the surface of the paint, turn on the machine.
8. Move the machine very slowly across the surface of the paint while applying approximately 5-15 lbs. of downward pressure. First move the machine in a back and forth motion
and then follow with an up and down motion.
Whether moving the machine up and down or side to side be sure to overlap your passes by 50%.
9. Continue repeating step #7 until the polish residue has turned clear. Once this occurs, while keeping the pad flat on the paint’s surface, turn the machine off.
10. Using a clean microfiber towel gently wipe the remaining polish residue from the paint. If the polish residue is difficult to remove spray the area with some water or quick detailer spray. Do not rub harder as this could create scratching in the paint.
11. Repeat steps 4-10 until all paint on the car has been polished.
If you have used either a medium cut or heavy cut polish to this point then repeat steps 3-10 using a finishing polish on a polishing or finishing pad. This will instill a high gloss shine in the paint.