As a car ages, its components begin to rust and lose integrity, creating a safety hazard for the driver. Unfortunately, you can’t stop rust — but you can slow it down.
Rust causes weakness in cars
Engineers have found that rust causes metal to lose structural integrity and become weak, so an older vehicle doesn’t perform as it did when initially crash tested. This problem is further compounded when you consider that ageing models also feature fewer modern safety technologies.
Case study: Mazda 6 vs. Volkswagen Golf
Swedish nonprofit group Villaagarnas Riksforbund, along with an insurance company, conducted assessments on two different models of car dating from 2003 to 2008 that are known to have rust issues in critical areas — the Mazda 6 and the VW Golf.
The Mazda 6 did not perform well under the test.
During the Mazda 6 test, in a frontal impact collision, the crash test dummy’s head made contact with the steering wheel after the airbag bottomed out. The dummy then bounced off the wheel into the door.
The car’s body shell deformed in an unexpected manner and the floor caused lower leg injuries when spot welds failed and separated. Crash engineers noted that a weak floor could allow objects to pierce the vehicle’s underside and enter the cabin — with disastrous consequences.
The Golf, on the other hand, performed remarkably, losing only a single point from its original crash rating.
Winner: Volkswagen Golf
Researchers concluded that in a heavily corroded vehicle, occupants had a 20% higher likelihood of dying in a crash.
The VW Golf performed much better in the tests than the Mazda 6. This underlines a key finding of the study, that each car rusts in a unique and individual way due to a range of variables, making them unpredictable.
The laboratory tested both cars to the same standards the cars had when new, not to more recent and stringent evaluations.
How to identify rust problems
Manufacturers apply anti-corrosion paints to crucial components at the factory, but eventually chips and wear cause coatings to break down. Drivers living in coastal areas will suffer accelerated oxidation thanks to a high salt content in the air. Vehicles taken onto the beach also suffer badly with rusting.
You can identify rust by bubbling, flaky paint and a red/brown pitting. Rust generally starts small but will get worse if left untreated. If you’re buying a car, take time to look underneath and examine the condition of structural metal components. If you see ragged holes and lots of loose corrosion, the car may be too far gone.
It’s possible to use a hammer to ascertain the condition of metal surfaces. If you tap the steel and it produces a sharp, defined ring, the metal should be in sound condition. If tapping makes a dull thud, the steel has most likely started corroding.
Is it plastic or metal?
If you notice a new ding or scratch or see paint flaking from your car, you might not need to worry about rust. Many new cars have more plastic parts than metal parts. Your whole bumper might actually be plastic, not metal, so a rear end accident might not be cause for concern about rusting.
If you’re not sure, your mechanic can check for rusting potential and suggest options for protecting your car after your paint has been damaged.
How to prevent your car from rusting
Once the rust on a part reaches a certain point, it will need replacing or repairing by a professional welder. You are far better off preventing rust by taking some simple precautions.
If you drive in seawater or even on the beach, take time to wash your vehicle off with fresh water. This eliminates salt, which is a catalyst for oxidation. Clean the underside of your vehicle, too.
If you spot surface rust or light rust, abrade the surface to remove pitting and flakes, then paint over it with a corrosion inhibitor and anti-corrosion primer/top coat. Look for marine grade products, as these often perform the best.
Greasing nuts and bolts with a non-metallic lubricant can ward off rust and make removal easier. There are also anti-corrosion sprays available.
If you notice a window, door or seal is leaking, get it fixed right away. Moisture will make rusting worse.
Is your car covered in an accident? Compare car insurance
If you’re driving a newer car, being proactive about rust can help you prolong its life. If your car is already nearly rusted through, upgrading to a newer, safer car could save your life in an accident, and the extra safety features could help you save on car insurance, too.
Frequently asked questions about cars rusting
Covering your car or keeping it inside can slow down the progression of rust, but it won’t stop it completely.
No. Rust damage is considered normal wear and tear to the car, which is generally not covered by insurance.
Yes. If your car gets scratched, has paint chipped off or gets damaged in any way that exposes the metal, it can begin to rust in as little as two days. If you see any metal spots on your car, it’s important to get them fixed as quickly as possible.
Dawn Daniels is a publisher with Finder, based out of Oregon. Her background includes editing more than 40 published books, including books on personal finance and meditation. In her spare time, Dawn enjoys hiking ridiculous distances and collapsing in exhaustion.
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