What is Car Polishing? (A Guide to Paint Correction)

Wondering what polishing a car actually means? What happens during the process? And why it’s a popular service? In this article I’ll take you through everything you need to know about polishing the paintwork on a vehicle.

What is Car Polishing?

Car polishing, also known as paint correction and enhancement, is the process of removing a very fine layer of clear coat paint. The aim is to remove defects such as marring, scratches and swirl marks in order to enhance the gloss and prepare the surface for protective coatings.

Polishing and Waxing are NOT the Same

Before we jump into the nitty gritty, we need to address a common misconception. There is a lot of confusion in the car care world over the difference between waxes and polishes. These products and the associated processes are in fact very different from one another.

Although both can be used to help make the paintwork look glossier, there are several differences between them:

  • Polishes are abrasive, waxes are non-abrasive
  • Polishes remove a layer of clear coat, whereas waxes do not remove any paint
  • Waxes add a layer of protection, whereas polishes do not typically offer any protective properties

It is common to first polish a vehicle, with the intention of removing defects, and then to wax the car afterwards to protect it.

Paint Correction Explained

Polishing is the process used to correct (remove/ minimise) defects in the clear coat, with the intention of enhancing the gloss. To understand this, let’s take a look at a diagram of the paintwork on a typical vehicle which has not been polished.

As you can see, the clear coat is the layer of paint that sits above the base coat which provides the colour. The clear coat is responsible for protecting the colour underneath from fading, and providing a shiny finish. Despite it’s protective role, the clear coat is easily scratched and marred. This generally happens when a vehicle is washed improperly e.g. by using abrasive tools such as sponges and brushes. These defects are highly visible in direct sunlight but also cause the paintwork to look dull in all conditions.

Here are some images of clear coat defects.

Severe clear coat defects
Minor swirl marks

In order to remove these defects, the paintwork must be polished. This process removes the damaged layer of clear coat, revealing a fresh, flat layer which reflects light evenly and looks ultra-gloss. Here is a diagram to demonstrate.

Before polishing

After polishing

Before polishing

After polishing

What Type of Scratches Does Polishing Remove?

Polishing is capable of removing scratches which are in the clear coat layer of paint, but is not capable of removing scratches which have gone through the clear coat into the base coat or primer. These scratches typically appear white or grey, and are visible in all lighting conditions.

Risks of Polishing

Polishing, when performed properly is not going to damage a vehicle. However, in order to ensure that polishing is done safely, there are several things that need to be considered.

Polishing is an abrasive process which removes a layer of the clear coat. The clear coat has a protective role which shields the base colour underneath from UV damage and fading, therefore it is important that polishing is only done when necessary, and excessive levels of clear coat are not removed.

At Auto Care HQ, we use a paint depth gauge to assess the thickness of the paintwork before proceeding with any polishing. This helps us to understand how much paint we’re working with and how much paint we can afford to remove to address the clear coat defects.

Sometimes it’s better for the vehicle to try and minimise the appearance of these clear coat scratches, rather than entirely remove them. This ensures that the clear coat integrity is maintained, but that the paintwork still looks glossy and fresh.

Hand vs Machine Polishing

The polishing process can either be performed by-hand or by-machine.

Machine polishing is faster and less labour intensive than hand polishing and also yields better results in terms of defect removal in the car’s paintwork. The advantages of hand polishing are that it makes it easier to access more intricate areas and it’s less aggressive and consequently, less risky. Auto Care HQ uses machine polishing techniques in order to produce professional-quality results.

Hand PolishingMachine Polishing
Slow and labour intensiveMore efficient process
Good for accessing intricate areasBetter for large sections
Less risk of removing too much paintMore risk of removing too much paint
Suitable for very light defectsMore consistent finish and best for deeper defects
Cheaper to get startedMore expensive equipment is required
Hand vs machine polishing

Please visit this article on autocarehq.com for more information on the pros and cons of each method.

Types of Machine Polishing Services

There are three main types of paint correction processes:

1. Polishing: uses very fine abrasives to remove minor swirls and scratches and enhance gloss
2. Compounding: uses moderate abrasives to remove deeper defects
3. Wet-sanding: uses heavy abrasion to address very deep clear coat scratches

These different processes can be used in combination with each other to deal with different levels of defects and address various levels of clear coat hardness. For example, a single-stage machine polish may be appropriate on one vehicle. Whereas on another car, a multi-stage process involving wet-sanding, compounding and finally polishing may be necessary to achieve the desired finish.

There are several different types of machine polishing packages available, the most common being:

  • Single-stage: using a 1-step polish to address swirl marks and enhance gloss
  • Two-stage: using separate compounding and polishing stages to address more moderate scratches
  • Multi-stage: uses wet-sanding, compounding and polishing to address heavy clear coat defects

What Equipment is Needed to Machine Polish a Car?

The amount and cost of the equipment needed to machine polish a vehicle is pretty hefty, that’s why a lot of vehicle owners take their pride and joy to a professional to get it polished rather than attempt it for the first time at home.

Here’s a list of equipment needed to machine polish a vehicle:

  • Dual-action, forced-rotation or rotary machine polisher
  • Polishing or compounding liquid
  • Microfibre, wool or foam polishing pads
  • Microfibre cloths
  • Panel wipe solution
  • Inspection light
  • Paint-depth gauge
  • Low-tac tape

How to Polish a Car

Before we even think about taking a polishing pad to the paintwork, we must ensure that it is prepared properly and completely free from environmental contaminants. These contaminants can include iron deposits, tar, mineral deposits, tree sap and either bonded particles which although invisible to the eye, cause the paintwork to feel slightly rough.

Here’s a rundown of the preparation steps:

  • Pre-wash the car using citrus or snow foam
  • Contact-wash the paintwork using a wax-free shampoo and microfiber mitts
  • Chemically decontaminate the paint using iron fallout and tar removers
  • Physically decontaminate the paint using a clay bar to remove any remaining bonded contaminants
  • Rinse and thoroughly dry the vehicle
  • Use low-tac tape to mask off any rubber seals, badges, plastics etc. surrounding the painted areas
  • Measure the paint depth using the gauge

Once the paintwork has been prepared, the polishing stages involve:

  • Attach the polishing pad to the backing plate of the machine polisher
  • Prime the pad using some of the polishing or compounding liquid
  • Spread the polish over a small section of the panel using low-speed
  • Increase the speed of the machine and with a slow-arm movement, work the polish across the paintwork in a cross-hatch overlapping pattern
  • Repeat for 2-3 “passes”
  • Remove the polish residue using a microfiber towel
  • Use a panel wipe solution to remove any polishing oils from the surface
  • Use an inspection light to assess the finish and repeat if necessary

Frequently Asked Questions

How often should a car be polished?

Cars should not be polished on a routine basis and the process should only be undertaken when necessary in order to preserve the clear coat.

Should I wax a car before or after polishing?

If wax is being used, it should only be applied to the car after polishing and never before. Applying a wax before applying a polish will cause the wax to be removed and the polishing stage to be far less efficient.

How much does is cost to get a car polished in the UK?

Machine polishing a car in the UK typically costs upwards of £400. The exact price depends on the size of the car and the level of correction. Please visit the price list for more information.

How long does it take to polish a car?

It typically takes 1-3 days to prepare a vehicle and polish it. The exact time required depends on the size of the car and the number of machine polishing stages being undertaken.

What should I do after polishing?

After polishing a vehicle it is essential to apply a layer of protection in the form of a wax, sealant or ceramic coating. The most durable and protective option is a coating, please visit my guide to ceramic coatings for more information.

Is polishing difficult?

Machine polishing a vehicle is a skilled process that carries risks if not performed correctly. This is why many vehicle owners choose a professional to carry out the paint correction process.

GET IN TOUCH

To book your car in for a valeting or detailing service get in touch today by either calling, emailing or completing the contact form and Heather will be in touch shortly

07894 074109
heather@autocarehq.com
8:30-6:00 Mon-Sat
Heather

Heather

Heather is a professional car detailer & valeter based in Cheshire and the owner of Auto Care HQ. A familiar face in the car detailing community, she has written over 200 car detailing guides on autocarehq.com and has produced over 165 videos on the Auto Care HQ YouTube channel.

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