A few minutes’ worth of careful filling and polishing can make most paint scratches nearly disappear.

New car + parking lot = scratches and chips. It’s a fact of life. Other people often don’t treat your car’s paint with much consideration. Ditto for kids and pets, not to mention the odd troll with an attitude and a set of car keys. Respraying a car can cost thousands of rand; respraying a single panel may leave you with a clown car that doesn’t match colour left to right.

Fortunately, many small nicks, scratches and imperfections can be easily retouched. A careful job is unobtrusive and may well be almost totally invisible.

Clear-coat scratch
Minor scratches, ones that don’t go through the clear coat into the colour, or areas of low gloss or orange-peel texture can often simply be polished out with compound. Yes, this removes some of the clear coat, so polish the minimum area necessary or you’ll have to respray some of that protective top layer. Thoroughly clean the panel after you’re done to remove the abrasive compound.

(1) Clean the surface fi rst to remove surface dirt. Masking nearby trim with tape might be wise, especially if it’s chromed plastic. Apply a small amount of polishing compound to the pad that comes with it, or even to a terry cloth or microfi bre cloth.

(2) Polish a small area. After a couple of dozen strokes, use a clean cloth to buff the area dry. Check your progress, and repeat if necessary. Go slowly to avoid sanding through the clear coat, and check often to see if the scratch is still visible.

Base-coat/primer scratch
You’ll need to get some matching paint. This same procedure can be used to repair primer-coat scratches by brushing in a layer of primer first, then sanding the overrun until it covers only the bottom of the scratch. Don’t skip that step: you’ll have poor adhesion and/or rust.

(1) Clean the panel with solvent to remove any oils or wax. Carefully apply primer or colour to the scratch. Yes, you’ll have paint overlapping the damaged area; it’s okay, but work carefully and minimise any lap.

(2) Let the paint cure at least overnight. With a sponge or rubber block as a backing, wet-sand with 600- or 1000-grit wet-or-dry sandpaper until any paint standing proud of the surface is gone. Work slowly, stopping often to clean the area and check your progress.

(3) Use compound to chase the gloss back into the damaged area. This will keep the sanded area more closely contained.

(4) You will probably have low spots. Apply more paint, and repeat until the scratch is filled and level. A final compounding should restore the finish’s shiny factory gloss. Don’t wax for 30 days to allow solvents to escape.

Spraying clear coat
Oops – if you’ve sanded through the clear coat or have repaired a deep scratch, you’ll need to apply clear coat. Buy a rattle can of automotive clear coat. Ordinary clear enamel won’t work – it has to be automotive paint intended for spot repairs. Rust-Oleum is one example of an appropriate product in aerosol cans. Here’s how to keep the repaired area small and unobtrusive.

Proper conditions: Be Comfortable
Before you break out your touch-up tools, figure out what you’re dealing with. If the scratch appears thin and white, it probably hasn’t penetrated through the clear coat. If it is body-coloured or shows metal, you’ve got a deeper problem. Regardless, never try to touch up paint unless the temperature in your work area is shirt-sleeve-comfortable for you. The paint won’t adhere, dry properly or gloss up.

The ideal temperature would be in the 20s, but 15 to 30 is acceptable. You’ll need to be out of the wind and sun. Indoors is best, but a shady carport should do. The relative humidity should be less than 60 per cent or so: the evaporating solvent will cool off the panel as it dries, potentially lowering the metal’s temperature below the dew point and letting moisture condense on the surface. This is not conducive to good surface fi nish.

Patience
Unless the car you’re repairing is over 20 years old or was custom-painted, the paint is almost certainly a clear-coated catalysed enamel. Artifi cially hardened by toxic chemicals, it’s stable within hours of factory application.

On the other hand, the paint you’re applying, whether it’s primer, colour or clear, is a lacquer. Lacquers dry because the solvent evaporates, leaving the solids behind. Although they may feel hard and be sandable within a few minutes, they will continue to shrink for a while. Allow lacquers to dry at least overnight so they can shrink before you add another coat. If you need multiple coats to build up the paint fi lm to full thickness for a repair, one coat a day is best. Of course, be safe. The amounts of solvents used are small, but work in a well-ventilated area. Make sure to degrease the area with solvent before starting.

Crackin the code
Somewhere on your car should be the factory-paint code, probably on a sticker or metal plaque under the hood or in the doorsill. This will help a great deal in finding the correct touch-up. It’s amazing how many similar colours there are in any car manufacturer’s palette in a single model year. If you can’t match the colour in the display of touch-up paints at the automotive paint or spare parts store, your next, albeit expensive, step is the parts counter at the car dealer, at least if you have a car that’s less than 10 to 15 years old. If you’re really stumped, an automotive paint dealer can custom-mix you a small amount; take in a sample, like the fuel filler cap or a mirror.

(1) Clean the surface with solvent to remove oils and wax. Cut a coin-sized hole in a piece of paper for smaller blemishes to avoid overspraying – you could also mask the area.

(2) Hold the paper a few centimetres from the panel and spray a light, dry coat through the hole. If it sags, you’ve sprayed too much. If it’s shiny, you’ve sprayed too much. Let this dry.

(3) Using 600- or 1000-grit wet-or-dry sandpaper on a sponge or rubber block, sand off any excess. This step is necessary to level the clear coat in the blemish, and also to keep the affected area from getting increasingly large as you add subsequent coats. As in a brush touch-up, compound the affected area to remove sanding scratches. Repeat this process with at least two coats, allowing 24 hours between coats.

Products
Walk into any car parts environment and you’ll see a variety of kits and products. I’ve always had polishing compound and fine sandpaper around the workshop. That’s really all you need, but it’s handy to have everything in one box. Some kits have the primer and clear already on board – all you really need in addition is the proper colour paint and a place to work.