Preventing rust on Ontario cars.

Steel rusts when it meets oxygen and moisture. Salt speeds that up by making the water more conductive, so corrosion happens faster. On an Ontario car in January, that usually means salty slush packed into wheel wells, rocker panels, door bottoms and the underside.

Paint is the barrier. As long as the clear coat and paint are intact, the metal is protected. Rust starts where that barrier breaks: stone chips on the hood, scratches along door edges, and seams where water gets trapped. Once the metal is exposed, it can spread under the paint (the bubbling you see on older cars).

So prevention has three jobs. Get salt off, keep paint sealed and keep water moving out of the places it collects.

It feels pointless to wash a car that will be dirty in a day, but the point is removing salt, not looking clean. A salty car left for weeks is worse than one washed regularly.

• Rinse the underside as often as practical, especially after a thaw when slush sits on the car. Touchless or self-serve bays with an underbody spray work for this.
• Pay attention to wheel wells, door bottoms and rocker panels. These trap salty water.
• Wash on a mild day above freezing when you can, so doors, locks and seals do not freeze shut. Wipe door seals dry.
• Do not skip it in a cold snap. Salt on the car does not stop working when it is dry.

For a full seasonal routine, our winter car care checklist and the guide on how to remove road salt from your car go through what to do, step by step.

A chip the size of a pencil tip looks harmless. It is a doorway to the metal. Touching it up takes ten minutes. Dealing with a rust bubble later takes a body shop.

1. Clean the chip with isopropyl alcohol on a cotton swab to remove wax and grease.
2. Check for surface rust. A little can be lightly removed with a fibreglass pen or fine abrasive tip. Keep it very small.
3. Apply touch-up paint in thin layers, with a primer if the metal is bare. Let each layer dry.
4. Seal with clear coat if your kit has one, then wait before waxing the area.

If rust has already bubbled the paint, or has spread beyond a few chips, touch-up is not the answer. At that point you are looking at a body shop, and we will say so. We do not do dent repair or bodywork, and a detail cannot fix rusted metal.

Cars are designed with drain holes at the bottom of doors, in the rocker panels, in sunroof channels and in the cowl at the base of the windshield. When leaves, grit or salt block them, water pools and rust starts from the inside.

• Clear leaves and debris from the cowl and sunroof drains in the fall.
• Check that door-bottom drain holes are open, using a thin plastic pick if needed. Do not use anything sharp.
• Keep wheel wells clean. A pressure rinse with warm water in spring clears packed grit.
• Look under the floor mats. Wet carpet over bare floor pan is a classic rust spot, and salt stains hold moisture. Our guide to cleaning salt stains from car carpet helps.

Undercoating and rust-proofing sprays are a separate decision from detailing. Many Ontario owners use annual oil-based or wax-based underbody treatments, and they can slow corrosion on older vehicles. Quality varies with the product and application. Ask what is used and whether it will affect your warranty. We do not apply underbody rust-proofing, so we will not claim to be the experts on that.

What we do handle is the paint and the cleaning:

• Winter salt removal gets salt out of the places it hides. The winter salt mess add-on is +$40 for winter salt mess when you book a package.
• Winter protection is our package for getting a car ready before the harsh months.
• Ceramic coating gives long-lasting paint protection that makes salt easier to wash off, though it does not stop rust on its own or prevent chip damage.

Be honest about limits. No coating or wax stops a stone from chipping the paint. Protect the finish, and check for chips each spring.

If you are in Burlington, Oakville or Milton and want help getting ahead of the season, send us a message through the 60-second quote form.