Polishing & Paint Correction

How to Remove Scratches From a Car’s Paintwork

14-07-2019

overview

Getting a car completely free from scratches, can be a tough- and on the other hand a very satisfying job. You need the right skills, but also the right knowledge to get the job done.

Scratches

Gloss is a reflection. You always need a light source to see gloss. If there are scratches in the paint, the reflection is disturbed and you will see less gloss. Gloss can be measured with a gloss meter on different angles. There are 3 angles to measure gloss. 20, 60 and 80 degrees. 20 degrees is only used on low reflective objects like wood. For paint 60 and  80 degrees is used.

Machines

There are different machines to polish your car. Traditionally, a rotary polisher is used. This machines gives fast results a deep cutting, but is difficult to handle if you are not skilled. Also you can buff holograms in the paint very easy. Nowadays there are also dual action polishers which have an orbit. This orbit varies from 3 to 21 mm. Due to this orbit less heat is brought in to the paint. The pad touches every orbit a different piece of paint and therefore you can polish without holograms.

A car’s paintwork is build up out of multiple layers. It starts with the body panel, and goes all the way up to the clear coat (the upper layer). There a difference between swirl marks and deep scratches. Swirl marks are multiple minor scratches. Deep scratches are bigger and have a ‘V-shape’. These damages have a big influence on the shining performance of the car. Scratches, swirl marks and also holograms can be detected by using sun- or halogen light.

How to remove scratches

Not all scratches can be removed. Some are so deep, that they have damaged the layer under the clear coat, the colour coat layer. These can’t be removed with sanding or a polishing machine. But scratches that didn’t hit the colour coat layer yet, are still removable.

There’s a lot to say about how to remove scratches, but in the end everyone has its own  favourite way of working. Still there are some very important basics that everyone needs to know when polishing a car. We made a  small checklist:

Checklist removing scratches

  1. Wash the car.
  2. Prepare the paint by removing contamination like brake-, rail dust and tar (product tip: Cartec Iron Wash with clay pad. For tar you use Cartec Tar and Glue remover.)
  3. Check the condition of the paintwork with sun- or halogen light.

  4. If it’s good enough for polishing, check the deepness of the scratches and swirl marks and decide what compound you’ll start with. This can also be done by simply doing a test on a small part of the paintwork. For this test you start with a finishing product. If the scratches can be removed easily, than you know the paint you are working on is relatively soft
  5. Polish the whole car in one, two or even three steps, depending on the condition of the paintwork.
  6. Make sure you do the car part by part and check if you’re making progression. After polishing degrease the polished parts with Panel Spray to check if polishing is done correctly.
  7. Check the condition of the paintwork again.

Pro-tip for step 7:

There are different measurement tools do this with, but an old school tip is to simply use your thumbnail. If the top of your nail is catching the scratch, it means the scratch is too deep. Note that if a deep scratch is in the clear coat, you have to polish away a lot of this layer. If you do that, it is possible to see a “dent” in the paint, so it is always important to consider if you want to polish it out completely.  If you wet the paint, you can see if the scratch disappears. If it does, the scratch will be in the clear coat and therefore can be removed. This is really important.

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