A scratch on a shiny car really hurts, especially if the owner really loves his cars. But with congested Indian traffic conditions and jealous neighbours, sometimes scratches either accidental or intentional have to be dealt with.
Not all scratches always require a repainting job. It depends on the nature of the scratch and the depth to which it has penetrated the surface. Some scratches can just be polished away, some need a bit of work, and deeper ones would actually require paint touch-up or worse still, an entire over-spray. Also read: Do you really need Teflon coating for your car?
To understand how bad a scratch can be, one should first look at how a car is painted. Over the sheet metal, the car first has a coat of primer, which is usually grey in colour (older cars used a red-oxide primer). Over this the car’s colour is painted on in two coats. The third coat is a clear-coat, a transparent layer that is painted on to bring out the depth and shine in the paint. Once these three layers have dried, the car is wax polished to give it a showroom-ready finish.
In the manufacturing process these days, painting is done in either a dip method (where the whole body is dipped in paint) and then the colour is spray painted on. Newer more eco-friendly methods also exist. Ford recently introduced a 3-wet paint process at its Chennai plant, which reduces water and fuel wastage in the paint process as well as reduces the time taken in painting by nearly 40%. Paint is dried in a paint booth or oven with heaters to dry it quickly. Also read: How to clean and protect your car during Holi
Dealing with paint scratches
Regular washing with poor quality cloth and too little water can result in circular swirl marks on your car. These type of scratches are unsightly, but easy to deal with as the marks have not dug into the paint and are only present on the clear coat (top coat) of the car. To prevent swirl marks or get rid of them, a good quality wax polish or even a Teflon coating would make them disappear. However, this is not a permanent solution, as it needs to be repeated often (as the wax layer or Teflon coating wears off with regular washing too).
Sometimes, if another car rubs against your car, you would notice that it sometimes leaves paint marks deposited on top of your car’s paint. This depends on the hardness of the object that rubbed against your car. A car with rubber bumper strips, for example, won’t scratch your paint badly, but would leave part of its rubber or paint on your car. To remove such kind of scratches, use car shampoo and water first. If the scratch is stubborn, then use a little rubbing compound on a soft cloth and gently rub it over the scratch. Don’t rub too hard, as it will damage your car’s clear coat. Once the scratch disappears, remember to wax polish the area to protect it.
If the scratch has penetrated the top-layer (the clear coat layer of the paint), you would be able to feel it with your fingernail. It appears white in colour, as the edges of the clear-coat are visible. To fix a clear-coat scratch, you get clear-coat pens in the market these days, which consist of a resin that fills in the scratch. These are effective for small scratches that have penetrated the clear coat only, but do not last too long (as they tend to rub off with washing). Remember to wax polish the area after the clear coat pen repair has dried up.
If the scratch is too wide or deep to be filled in with a clear coat pen, you will need to “rub” the area. What this does is to even out the surrounding areas of clear coat paint to the depth of the scratch. This can be done with rubbing compound and a soft cloth. One could also use superfine grit emery paper for bad scratches. Then wax the repaired area to restore the shine, but remember this area would now be quite vulnerable to future damage as there won’t be much top-coat left.
Base coat scratch
If a scratch has penetrated through the clear coat layer and through the base coat, the primer (grey colour) or even the metal will be exposed. In such cases, dealing with the scratch is far more difficult. The ideal repair would be to sand down the entire scratch and get a full paint over spray done.
However, if it is a thin scratch, you could try a touch-up repair. Get a paint touch-up pen (available at large car accessory stores and online) that matches the colour of your car or get a spray paint touch-up can. Wash and clean the area to be repaired. Then mask the surrounding area with newspaper and masking tape, leaving only the scratch area exposed. Using the paint touch-up pen, gently fill in the scratch. Or if it is a wider scratch, use the spray paint can and gently spray over the area in even strokes.
Let the repaired area dry (it can take up to a day). It will look bad initially, as the over-sprayed paint area would appear higher than the surrounding paint area. You will need fine grit emery paper to then sand this down to the level of the surrounding paint area and finish it by using a soft cloth and rubbing compound. Repeat the process till you get a satisfactory result. Then use wax polish to protect the area.
Some tips to prevent scratches include washing the car with plenty of water and using separate cloth and water bucket for the body and wheels of the car, to prevent grit for spoiling the paint. Don’t ever dry-wipe the car as the dust can scratch the clear coat. Getting a Teflon coating done would help prevent scratches for up to six months on the car, but it is an expensive process. Regularly applying wax polish once on a month on the car can work just as well in maintaining the finish.
Companies like 3M have come up with paint protection film, which is a transparent polythene film that is stuck over the painted surface of the car. This is expensive and costs up to Rs. 450 a square foot, but is effective in protecting the cars paint from minor scratches. Paint sealants and lacquer coating too work well, but last for only about a year. Also read: How to drive in slow moving city traffic