Car scratch and paint repair

How deep is the scratch?

Car paint is built up in layers. On most modern cars there is a clear coat on top, the colour (base coat) under that, then primer, then the metal or plastic panel. The right car scratch repair depends on which layer the scratch has reached.

The quickest way to find out is the fingernail test: wash the area and run a fingernail gently across the scratch.

The test takes less than a minute and stops you buying the wrong products for your car paint repair.

Car scratch repair cost in NZ

Colour makes a difference: metallic, pearl and three-coat finishes take more work to match than solid colours. The size of the panel and whether the paint needs blending into the next panel also change the price.

How to fix light scratches yourself

Scratches in the clear coat are the easiest to fix at home, and the right products are sold at any car parts store.

1. Wash and dry the area. Dirt left on the paint will cause more scratches as you polish.
2. Check the depth with the fingernail test. If you can see primer or metal, stop here and see a professional.
3. Polish the scratch. Use a scratch remover or polishing compound on a clean microfibre pad, working a small area with firm, overlapping strokes. A dual-action machine polisher gives a more even result than hand polishing.
4. Touch up deeper marks. For scratches into the colour, apply touch-up paint matched to your car’s colour code in thin layers, let it harden fully, then polish it level.
5. Protect the paint. Finish with wax or a paint sealant to protect the repair.

Your car’s colour code is on a label, usually in the driver’s door frame or under the bonnet. Touch-up paint mixed to that code matches much better than a generic shade. Keyed scratches are a different matter: they are usually too long and deep for a good DIY result, so see the FAQ below.

Stone chips and paint chips

Stone chips collect on the bonnet, front bumper and below the windscreen. They look small, but a chip that goes down to bare metal will start to rust, especially near the coast.

To fix paint chips on a car, clean the chip, remove any loose paint or rust, then build it up with thin layers of touch-up paint applied with a fine brush or a toothpick. Let each layer dry before adding the next, until the chip is level with the paint around it. Big paint chips, or a bonnet covered in them, are a job for a smart repairer or paint shop.

Faded paint, sun damage and peeling clear coat

New Zealand’s strong UV is hard on car paint, and the roof and bonnet take the worst of it. Sun damage shows up in two different ways:

• Oxidation. The paint looks dull, chalky or faded, often on older red and dark cars. Machine polishing (a “cut and polish”) can bring much of the colour and gloss back.
• Clear coat failure. The clear coat turns milky, cracks or peels away in patches. Polishing can’t fix this. The panel has to be sanded back and repainted.

If you are trying to fix faded paint on a car roof, start with a test patch: if polishing brings the shine back, keep going; if the surface stays rough or patchy, the clear coat has failed. Waxing or sealing the paint a few times a year and parking in the shade slow both problems down.

When to use a paint shop

A professional repair is the better choice when the scratch reaches primer or bare metal, when the damage covers a large area or several panels, when the car has a metallic or pearl finish, or when you are returning a leased car or selling it soon.

For small areas, ask about a smart repair (small to medium area repair). The technician repairs and repaints just the damaged spot and blends it into the panel, which is quicker and cheaper than respraying the whole panel. Many smart repairers are mobile and work at your home or office.