Car Polishing: What Does it Do and How Does it Work?

Car polishing is a widely misunderstood process, but one that is really important to make the paintwork look as shiny as possible. In this article, we will be going through exactly what the function of a car polish is, the risks, limitations, the process and the preparation required to get the best finish.

 

At a Glance

Car polishing is the process of removing minor clear coat damage (scratches and swirl marks) using a polishing liquid to flatten the clear coat which increases the gloss-level. The polishing process can be performed by machine or by hand and should be followed by protecting the paint using a wax, sealant or coating.

Diamond Cut Detailing offers single and multistage paint enhancement and correction services. Lewis, the owner and detailer is highly trained in the technique of machine polishing, ensuring the best possible finish in achieved in a safe manner.

 

Polish Isn’t the Same as Wax

This is perhaps one of the biggest misconceptions in car care. A lot of car owners fall into the trap of using the terms “wax” and “polish”, interchangeably, but they actually have very different functions.

Car polishes are mildly abrasive, meaning they have the ability to flatten the clear coat (the top layer of paint on the car). This removes any light imperfections, usually inflicted during the wash process by using sponges, brushes or other aggressive techniques of cleaning the paintwork. The overall aim, is to improve the gloss level. Simply put, the flatter the clear coat, the shinier the paint.

Waxes are not abrasive and leave a protective layer on the paintwork to help shield it from UV rays, dirt, road grime etc. They do not have the ability to flatten the clear coat since they do not contain abrasives. Polishes do not protect the paintwork, so it is important to wax after polishing to protect the finish.

The confusion between waxes and polishes probably arises from the underlying claims that they both make the paint look shinier. Waxes tend to contain chemicals which will add some level of gloss to the paintwork. However, they do not have nearly as much of an impact as polishing. A truly glossy finish comes from the flatness of the clear coat, not what you put on top.

 

How Does Polishing Work?

We’ve touched on this already by saying that polishes are abrasive and help to flatten the clear coat, however it really requires a bit more explanation. The clear coat on a car is very rarely completely flat and will contain some level of damage, unless the car has been recently polished and well-maintained.

Polishes contain mild abrasives in a liquid format which are designed to remove the damaged layer of clear coat, to reveal a fresh, flat layer of paint. They can be applied using a machine polisher, or by hand with a foam or microfiber pad. They are applied in circular motions, on a small area at a time and worked into the paintwork with the aim of removing an even layer. Once the polish has been worked in, the residue can be buffed away using a microfiber towel. It may take multiple attempts on the same area to achieve the level of finish that is required.

 

What Types Scratches Can Polishing Remove?

Polishing is only capable of removing very fine clear coat scratches. It is not capable of removing scratches that have gone through to the base coat, which usually appear white in colour. Polishes are only designed to really refine the paintwork to a mirror finish.

In order to deal with deeper clear coat scratches, other techniques can be used instead. The most common, is called compounding. Compounds are still used in the same way as polishes, and exist in a liquid format containing abrasives, but they have a higher level of “cut” (abrasion), compared to polishes. These means they are more capable of efficiently removing clear coat damage. Keep in mind though, that they cannot deal with deeper scratches that have penetrated the base coat, as this will require the addition of paint.

Compounds can sometimes leave some very light “hazing”, since they have a higher level of abrasion. Compounding is typically followed up by polishing to refine the paintwork and remove the hazing to leave a glossier finish. This is known as a two-stage paint correction, the first stage being compounding to remove clear coat scratches, and the second being polishing to refine finish.

There is also another technique used to correct clear coat scratches, called wet sanding. This is even more aggressive than compounding and is used to deal with severe clear coat damage. It will leave a haze behind, which can be removed with a compound and followed by a polish to reveal the shiniest finish possible.

 

Risks of Polishing

Before polishing a car or using any of the paint correction/ enhancement techniques described above, it is important to understand the risks involved. Polishing is an irreversible process, once you’ve removed a layer of the clear coat, you can’t get it back.

The clear coat has a protective role as it sits on top of the colour coat to shield it from UV rays, dirt and grime to help it maintain its colour. Removing a layer of the clear coat by polishing, should only be done when necessary, and with caution, in order to avoid removing excessive levels of the clear coat and risking the integrity of the colour coat underneath.

Since you cannot see the thickness of the clear coat visually, the safest approach to take, is to use a paint depth gauge. This allows you to gain some information about how much clear coat you can safely remove. Once you know how much paint you’re dealing with, the best approach is to use the least aggressive technique first, then if you need to use more abrasion, you can step it up.

 

Hand vs Machine Polishing

Before we jump into the process, it’s important to distinguish between machine and hand polishing. It is possible to get a good finish from either technique; however, machine polishing will achieve a better finish in comparison. Hand polishing is less risky though, as you are unlikely to remove as much clear coat. For a complete beginner, it is usually best to start with hand polishing whilst you get used to the technique.

Machine polishing requires more experience and skill. It is possible to machine polish a car by yourself, however, most car owners do not have the expertise or confidence to take a machine polisher to their car’s paintwork.

 

How to Polish a Car

In this next section of the article, we will be discussing how to polish the car safely to get the best results. This involves properly preparing the paintwork, which is an essential step to take care of before even thinking about picking up the polish.

Preparation

To polish a car properly, you need to ensure you’re dealing with completely clean and bare paintwork. Here is a brief outline of how to do it:

  • Pre-wash the car using a snow foam.
  • Clean the wheels.
  • Use safe wash technique (two-bucket method) to clean the paintwork with a wax-free shampoo.
  • Strip any waxes or sealants.
  • Chemically decontaminate the paintwork using an iron fallout remover and tar remover.
  • Physically decontaminate the paintwork using automotive clay.
  • Dry the car using a microfiber towel or compressed air.
  • Use a panel-wipe solution to remove any residue.
  • Ensure the paintwork is completely free from dust before polishing.
  • Tape over any plastic or trim with low-tack tape.

 

What You’ll need

The kind of equipment you will need depends on if you’re trying to machine polish, or hand polish the car. You’ll need less equipment to hand polish the car. Here is a quick rundown of equipment for each technique.

For Hand and Machine Polishing:

  • Polishing liquid
  • Microfiber or foam pads
  • Microfiber cloths
  • Inspection light
  • Low-tack tape
  • Panel wipe solution
  • Paint-depth gauge

 

Machine Polishing Only:

  • Machine polisher (dual-action or rotary)
  • Backing plates to attach the pad to the machine

 

The Process

Once you’ve properly prepped the paint and got all your equipment together, you’re ready to start polishing. It is possible to polish the car outdoors but be mindful of the weather and dust build up on the panel. If you have access to an indoor or undercover space, then it is definitely worth making use of it.

Here is a brief outline of the stages involved:

  • Prime your pad, using the polishing liquid by ensuring it is evenly coated in a thin layer.
  • Add 3-5 pea-sized dots of polish to the pad, and dot this over the panel.
  • Work in small sections at a time (usually ¼ the size of the bonnet).
  • Work the polish into the paint using circular motions if polishing by hand, following a crosshatch pattern across the panel.
  • If using a machine, spread the polish over the paint at low speed, then turn the speed up (usually around 2/3 the speed on most machine polishers). Work the polish in, using an overlapping crosshatch pattern for 2-3 cycles.
  • Buff the polish and residue away using your microfiber towel.
  • Use the panel wipe solution and a fresh microfiber towel to remove any polishing oils.
  • Inspect the paint using your inspection light to see if you’re happy with the finish.
  • Repeat if necessary.

 

Polishing Variables

As you’ve probably already gathered through this article, there are many caveats to machine polishing. The aim of this article is to keep everything simple and straightforward to help you understand the process, however, we can’t discuss polishing in its entirety without talking about all the variables to consider.

For beginners, it’s best to keep things simple and start with hand-polishing. Once you’ve become comfortable with that, then you can step up to machine polishing, and this is where things get a bit more complicated. Here are the main variables to consider at this level:

  • The type of machine polisher (rotary or dual action)
  • The type polishing pads (varying materials, shape, size and pattern)
  • The type of compound or polishing liquid: this ranges from brand to brand, but most companies offer a “heavy cut” compound, “medium cut” compound, all-in-one, and a finishing polish.
  • How soft the paint is (some cars have paint which will be abraded away more easily than others).
  • The speed the pad rotates, and the pressure.
  • The “work-time” of the compound or polish.

If you are new to machine polishing, then the best thing to do is to pick a dual-action polisher, and an all-in-one compound and polish, with a moderately firm foam pad. This will usually get the best results for beginners who just want to keep everything simple.

 

Frequently Asked Questions

To round everything off, here are the answers to some of the most frequently asked questions about polishing a car.

How often should you polish a car?

Polishing a car should typically not be performed as part of a routine, instead it should only be done when required. Over-polishing the car and removing unnecessary clear coat is potentially harmful to the colour coat underneath.

Should I wax or polish my car?

Polishing should be performed when you are trying to remove mild defects in the clear coat to enhance the gloss-level. Waxing should be performed when you just want to add some protection to the paintwork.

Should I wax the car before or after polishing?

Waxes should always be applied after polishing, and never before. Waxes will interfere with the polishing process and should be applied afterwards to add a layer of protection to the paint.

How much does it cost to get a car professionally polished?

The cost of getting a car machine polished depends on the size of the vehicle, the level of enhancement required, the current condition of the paintwork and the skill level of the detailer. In the UK, paint correction detailing packages typically start from £250.

 

Diamond Cut Detailing offers single and multi-stage polishing packages to enhance the finish and level of gloss to the paintwork. Lewis, the owner and detailer, has a high-level of experience in machine polishing and operates in a specialist detailing centre in Exeter, specifically designed to provide the optimal conditions to provide paint correction and enhancement services.

Get in touch by calling on 07730 783808 or by emailing info@diamondcutdetailing.co.uk.