What is a polish? How are polishes used in paint correction?
Before we answer the question, what is a polish, let us first get a basic understanding on why someone would want to use a polish. The most common reason to polish paint is to remove defects in the finish, such as swirl marks, scratches, water spots and other blemishes. These imperfections in the finish will cause the paint to look dull, muted, hazy, as well as create an impression that the paint is not properly cared for. Swirl marks are often the most common form of imperfection and can be easily detected on darker colors when exposed to a light source.
As you can see from the picture, the imperfections are an eye sore! All of those fine scratches, or swirl marks, are dips and valleys on the painted surface. These dips and valleys will not allow the light to reflect back properly and they cause the paint to have a dull look to it. In extreme cases, black paint can even look gray. If you paid extra to get metallic paint as an option, those tiny flecks of flake can become lost behind a wall of imperfections. Needless to say, nothing good can come out of having defects in your paint. The good news is proper polishing can restore clarity, gloss and excitement to your paint once again. In order for paint to reflect light, the surface must be as smooth as possible. This would allow light to pass through the clear coat, reflect off the color layer of paint, producing a mirror like effect.
What are polishes and how do they work?
Polishes come in a variety of types, but the most common ones used in professional detailing are abrasive polishes. Abrasive polishes are used to even out the clear coat by removing a micro-thin layer of paint. When this process is performed properly, the results can be nothing short of amazing. Below is a diagram that can help visualize the polishing process. The image changes every 5 seconds.
The first slide you see represents a cross section of paint. On the left side, the jagged lines show small dips and valleys in the clear coat which represent swirl marks. On the right side, you see a large cut, which represents a deep scratch. Notice the scratch goes down through the entire layer of clear coat and penetrates into the color layer. It would not be safe to try to completely remove that scratch. In order to completely remove that scratch you would have to remove the entire layer of clear coat and small amount of the colored paint in that area. The green line on the second slide illustrates your target amount of clear coat removal. Removing clear coat to that depth would completely eliminate the swirl marks (since the green line is below the deepest valley in these shallow scratches). The scratch will also be improved slightly because the edges will be rounded off during the polishing process. This is the result of the abrasive particles in the polish smoothing out the ridged edges of the scratch. Sometimes this can help hide the scratch so that you would only see it at certain angles or lighting. The final slide shows this completed process.
Compound vs. Finishing Polish
Generally speaking there are two types of abrasive polishes, compounds and finishing polishes. A compound is designed to cut through the clear coat aggressively. It can accomplish this in two ways, using larger abrasive particles or utilizing a higher concentration of smaller abrasive particles. Compounds will typically leave behind a slight haze on the paints surface. This happens when the abrasive particles are not completely broken down and the clear coat is left with a slightly jagged surface. It is always recommended to follow up a compounding step with a finishing polish. Finishing polishes have smaller and more refined abrasive particles. This allows you to even out the clear coat to a much finer degree than is possible with a polishing compound. Using this combination correctly will leave you with a glossier and more reflective finish. It is often the finishing polish that yields the most dramatic results in the detailing process. In certain situations, a finishing polish can be used as a single step to remove some minor defects. We advise starting with the least aggressive approach to obtain the results you are looking for in order to preserve as much clear coat as possible.
Other factors that will have an impact on your polishing results are the technique used to apply the product, the amount of pressure used, and the method of application. Applying a compound by hand with a foam applicator pad will yield different results than applying it with a quality buffer and a microfiber cutting disc. Sometimes the difference can be night and day even though you are using the same exact product. Just because you use the right tools and product combination won’t guarantee results either. Experience using a buffer, knowing how a particular product reacts, knowing hardness of the paint, ambient temperature, how clean the pad is, the speed used on a buffer, the amount of pressure applied, what type of pad is being used and other factors will all have an impact on your results. If there were one simple solution to paint correction, professional detailers would all produce the same results and this is far from the case!
Recommended compound and finishing polish
While there are no magic combinations that produce flawless results in every situation, there are some products that are proven to be effective for most. A wonderful starting point is the pairing of Meguiar’s M105 Ultra-cut Compound and the Meguiar’s M205 Ultra Finishing Polish. One of the main reasons these products come so highly recommended is because they contain non-diminishing abrasives that allow them to work well when applied by machine or by hand. Those who do not want to invest in a quality buffer setup can still achieve great results with this Meguiar’s combo. I personally use these two products by hand when removing scratches and scuffs from behind door handles and other areas the buffer will not reach. The right technique on the Griot’s buffer and proper product and pad combinations can result in a professional finish your first time around! Bottom line, the M105 and M205 products are versatile and you can grow into them, making them a must have for any level detailer.