In winter, vehicles have a rough ride: struck by gravel chips (called aggregate) from the abrasive mix spread on roads, and covered in residue from the salt. That combination creates the perfect conditions for rust: as soon as the bare metal of the bodywork is exposed, oxidation starts. Over time, the corrosive assault shortens the useful life of vehicles and greatly reduces their resale value.

And there’s no point hoping for the automaker’s warranty to come to the rescue: it won’t cover this type of rust problem, because it isn’t caused by a manufacturing defect.

So with that in mind, let’s say you’ve decided to take matters into your own hands and protect your vehicle. That’s a wise move. There are some simple ways to prevent damage, and to repair it as well.

The keys to preventing damage

Here are some helpful hints on how to protect your car from the harmful impact of abrasives and salt:

  1. Slow down – This lessens the impact of abrasives flying up onto your car’s body and windshield. As a bonus, you’ll save on gas!
  2. Keep your distance – The farther back you stay from the vehicle in front of you, the less debris will be thrown onto yours.
  3. Have the vehicle rustproofed – The treatment won’t help against flying aggregate, but it will protect the components of your vehicle against the ravages of salt. This is an investment that pays dividends if you want to keep your car for a long time.
  4. Have mud flaps installed – These inexpensive accessories help protect your car’s undercarriage.
  5. Wash your vehicle often (when the temperature permits) – This will rid the vehicle body of salt and grime. Use plenty of water on the wheel wells and surrounding areas.
  6. Have transparent plastic protector strip installed in strategic areas – The strip can turn yellow over time, making it unattractive against light-coloured paint, so it will need to be changed more often (be sure to entrust the job to a professional, who can remove the strip without harming the paint).
  7. Equip the vehicle with a hood protector (a/k/a “car bra”) if necessary – This protects the front of the hood from flying aggregate (which can chip the paint).

Note, however, that sand, salt and dust can get between the bra and the hood, where it can scratch or tarnish the paint. The solution to this is to wash the bra (as well as your vehicle) once or twice a month, especially in winter.

When the damage has already been done: essential care

If all that distance travelled on winter roads has left your car looking the worse for wear, here is a guide to corrective action, organized by type of damage.

To do spot repairs to the paint yourself, you’ll need primer (ideally) along with a small quantity of paint identical that of your vehicle; you can probably purchase some from your dealership. Otherwise, you can buy a spray can of paint from a specialized retailer, to perfectly match the colour code for your make and model. 

Paint chipping – Start by cleaning the chipped area using a solvent designed for this purposes. If you can’t find any, use water and wax-free soap. Allow the area to dry thoroughly.

Check to see if the original primer is intact. Shake the container of paint well, remove the applicator, and wipe any excess paint from the brush onto it.

Using the brush, touch up the spot, covering any visible primer. Warning: If you wait too long to repair the paint, you will probably see areas of rust or blistering paint start to appear.

Scratches – To improve the appearance of scratched paint, first buy some rubbing compound, which is a gentle abrasive that comes in paste or liquid form.

If you are using an electric buffer, it’s best to use liquid compound (which, incidentally, can be used to polish the entire paint job, not just scratched areas).

If you are polishing by hand, use the paste type of compound, following the instructions provided on the packaging (the basic rule is to polish using a circular motion.

Finish up by waxing the vehicle. Hint: coloured waxes do a better job of hiding scratches.

Blistering – A blister or bubble in the paint means there is rust underneath. Remove the paint using a razor blade or small knife. Then use a screwdriver or blade to scrape the rust off. The metal must be completely bare, free of all rust.

Clean the area to be treated, then apply primer using a small brush, a toothpick or even a match, and allow to dry. Shake the container of paint well, and apply a sufficient quantity of paint to cover all of the primer, avoiding any of the original paint.

Large areas of rust – You can use the same technique as for blistered paint, on a larger scale, or try the somewhat more complicated method of removing the rust using a sanding disc mounted onto an electric drill (use coarse-grit sandpaper for this stage).

Next, sand the surface using 320-grit wet sandpaper to smooth out the damaged surface. Run your hand over the sanded area to detect any imperfections, and then sand again as needed.

Use metal conditioner to clean the metal and improve adhesion of the primer and paint. Mask all areas where the old paint is intact and you don’t want new paint to go.

A tip for spot-painting a small area: cut a hole about the size of a quarter in a piece of cardboard, then spray-paint through the hole, holding the cardboard about four centimetres above the spot to be painted.

To paint over a larger area, spray the primer, and then the paint, from about 25 centimetres away. Keep the spray can moving, sweeping back and forth; work from the top down to prevent dripping. Don’t try to cover everything at once: several light coats will give the best result.

The worst thing to do is nothing

When it comes to prevention as well as repairs, you don’t want to don’t let rust win the battle!

Fixing damage to the paint on your car yourself is better than doing nothing at all. But know your limits: do-it-yourself touch-ups likely won’t blend well, and if you’re a perfectionist by nature, you’ll find those little defects annoying. In that case, your best bet is to go to a body or detailing shop!