Car scratch repair: a complete guide
Small scratches cause frustration and can prove costly to fix or when it comes time to sell. We explain how to repair them at home
Throughout the time you own a car, it’s almost inevitable it'll pick up some scratches, even if you’re very careful. Overgrown hedgerows, stones flicked up by traffic and careless passers-by in tight car parks all make keeping pristine paintwork very difficult.
If you notice a small scratch, it’s a good idea to try and correct it as soon as you can. This is because paintwork is like a protective skin, and exposed metal will begin to corrode without repair. Not only can scratches spoil your car’s styling, they can also affect its value if left until you decide to sell on.
If damage is more extensive with deep scratches, we’d always recommend seeking the advice of a professional bodyshop, but minor scratches can be tackled at home with products specifically geared towards owners. Take a look at the directions, and only undertake the job yourself if it seems simple and within easy reach of the manufacturer’s claims – otherwise, use an expert.
Minor paintwork damage is so common there’s a whole industry of businesses geared up to carry out repairs – including many who work out of vans and will come to your home or workplace for added convenience. On-the-spot repairs for scrapes and scratches are usually quite affordable, costing around £100 to £200 for minor damage to a single panel, and rarely exceeding £500. Usually, you can also get a free quote before deciding to go ahead, either by sending a picture of the damage or describing it.
This guide is intended to help you decide whether you can get a great DIY result, or if you’re best off leaving the repair to the experts.
How deep is it?
Even more than its length, it’s the depth of a scratch that determines if a DIY fix is possible. Deeper scratches mean more damage has been done, and the job of correcting it is also more complex. If it runs deeper than just beneath the surface, it may be best left to the professionals.
A car’s factory paint finish is usually made up of three layers. The first layer will consist of a primer and corrosion preventer, and this supports the colour layer, helping it adhere to the car’s metalwork. The top layer is a clear coat, or lacquer, which gives the car its shine and lustre. Each of these layers can be made of several coats, and applying special finishes such as metallic, pearlescent and ‘flip’ colours can be very involving.
If you gently run your fingernail over a scratch, and its depth feels no greater than the thickness of a piece of paper, it could be that only the clearcoat lacquer is damaged – a relatively straightforward issue to fix.
With deeper scratches (which may feel like a ridge), the base coat and primer may have been penetrated and there could even be bare metal. In severe cases, damage like this may need professional attention.
Repairing a car scratch: what do you need?
Predictably, the deeper the scratch, the more time and equipment you’ll need. Inspect the area around the scratch thoroughly for signs of rust. If you find any, you’ll need to apply a rust converter such as Hammerite Kurust or Jenolite. Follow the instructions carefully and allow it to dry completely before repairing the paint damage.
If your scratch is relatively minor, you can use a scratch-removing liquid such as T-Cut, Farecla G3 Professional Scratch Remover or Autoglym Paint Renovator. These abrasive fluids are also known as cutting compounds and remove the top layer of paint to eliminate and ‘polish out’ the scratch.
If the scratch has damaged the base coat, you’ll need to buy some touch-up paint. You can give your car’s registration to your local main dealer who’ll be able to sell you the correct colour. Alternatively, if you can find out the manufacturer’s paint code – usually found on a metal plate in the doorjam or under the bonnet – you’ll be able to buy the correct colour online or at your local car spares store.
A word of caution, however. Even if you get the correct paint colour, there’s still a possibility it won’t be a perfect match. That’s because there can be slight variations in the precise colour of batches of paint, plus your car’s exposure to the sunlight can gradually dull the paint.
If you use touch-up paint, you’ll usually be able to tell where this has been applied if you look closely, but it’ll obscure the most obvious chips and scrapes from a distance and many people are quite happy with this result.
Keep it clean
However you repair a scratch, it’s important the area you are working on is spotlessly clean, as dust and dirt can be inadvertently rubbed in, damaging the paintwork. It’s also a good idea to work on as small an area as possible, whatever method or kit you’re using.
Using a scratch remover or cutting compound
Using a cutting compound is little different to applying a wax. Apply the fluid using a clean, lint-free cloth in gentle circular motions until you can no longer see the scratch. The deeper the scratch, the longer it’ll take.
Once the scratch has gone, you should allow the compound to dry completely and brush away any dried excess. The cutting compound will have removed some of the protection afforded by the topcoat, so it’s important to apply a coat of wax at the end of the process.
Remember, the majority of scratch-repair kits work by abrading through the clear coat layer and blending in paint from the base coat to fill in scratches. If you rub too hard or for too long, it’s quite possible to damage your car’s paint permanently, leaving you with a multi-coloured eyesore.
Using car scratch repair kits and pens
Touch-up pens can be bought for a few pounds, but depending on the product you choose, you may find some more effective than others. Most of them are non-colour specific and use solvents that work in a similar way to cutting compounds. It can be difficult to get consistent results with these.
It’s also possible to buy more comprehensive touch-up kits. These usually comprise a series of very slightly abrasive cloths, and a spray lubricant. Using these together allows you to polish out a scratch and blend it in with the existing paint. Most of these kits also come with a final clear wax or fluid to give added protection to the repaired area.
Whether you’re using a pen or a more comprehensive scratch-repair kit, it’s a good idea to test the product(s) on an inconspicuous area before you start and use masking tape to separate the area you’re working on, ensuring that you don’t go overboard in your application. Make sure you closely follow the instructions that come with any product you’re using and remember: less is usually more when it comes to repairing car scratches.
You should avoid treating scratches in the rain or when it’s particularly windy, hot or cold, as these factors can all compromise the quality of the finish.