Rust is a silent car killer. It can make an expensive car look like a beater. It lowers the resale value of a vehicle, and if left untreated, will make your car unsafe to drive. Ignoring it can send your car to an early grave. But rust is treatable and can even be prevented entirely. Understanding what causes rust, and how to identify it can prevent rust from ever becoming a problem.
What Is Rust?
To understand what rust is and what causes it, it’s helpful to use its proper name – iron oxide. Iron oxide is made up of two atoms of iron and three atoms of oxygen. It forms when an electrochemical reaction (called corrosion) takes place. Corrosion occurs when an iron-containing metal, as found in your car body, undergoes prolonged exposure to oxygen and moisture.
Rust only needs two electrodes (anode and cathode) and an electrolyte to appear. And, guess what? The electrodes are already present in your cars metal body. From there, it’s a case of just add water (electrolytes), and you’ve created the perfect condition for rust.
When electrolytes are added to these specific electrodes, it provides additional oxygen. This then leads to a chemical breakdown that prompts the anode to release electrons. The water acts as a carrier for electrons to pass between the two electrodes. As this occurs, the anode creates an oxidized ceramic layer, leaving its mark on your car body as rust. If water can’t make contact with the exposed metal, the surface is safe from rust.
How The Environment Makes Rust Worse
Iron oxide can occur in any place on earth, but some environments are optimal for rust to occur. People who are lucky enough to live near the ocean have to trade off the higher chance of rust due to the increased salt and humidity.
We know why water causes corrosion, but it is a poor conductor of electrons and not as efficient a conductor as salt water. Salt can also come from the air or found on the road when it snows. However the most obvious source of water remains rain. So, if you are expecting bad weather, cover your car if possible. If you live in an environment that increases the chance of rust on your car, a professionally applied protective coating can lessen the risk.
How Does Rust Damage A Car?
One way that rust will damage a car is by eating away the body and chassis, causing structural failure. Once this occurs, a vehicle is considered too unsafe to drive. Your car’s paintwork provides a level of protection against this by preventing water meeting bare metal. If your paintwork is scratched, chipped, or damaged from acidic bird droppings, the exposed metal will eventually begin to rust.
Rust inside the engine is another serious cause for concern. Water can find its way in through low-quality fuel or, more commonly, condensation. If this occurs inside the engine cylinder and comes into contact with your engine’s pistons, it can cause scoring (excessive wear). Modern lubrication systems prevent this from occurring, but care needs to be taken to not expose an engine to the elements unnecessarily or use low quality fuel.
Electronics and electrical systems in modern cars are becoming increasingly complex and can also be affected by rust. They are generally well protected, but if water is regularly finding its way inside your vehicle, the electronics can short out and stop operating altogether.
How Much Rust Is Too Much?
Believe it or not, the police can order your car to be towed for excessive corrosion, so the question has to be asked – how much rust is too much? Some people couldn’t care less if their daily driver is carrying a little rust, but one problem with rust is that it spreads, and needs to be taken care of as soon as possible.
Some rust is cosmetic, some is structural, and some may even be hidden. If you notice any rust on your vehicle, it pays to get a professional panel beater to investigate, so you know exactly what you are dealing with and what your options are, before it spreads and becomes untreatable.
What Are Common Areas of Rust On Cars
Some areas of a vehicle are more prone to rust and these include:
- Any exposed, bare metal
- Anywhere water is gathering
- Trunk compartment
- Around trailer hitches
- Frame/chassis
- Wheel wells and hubs
These should be paid extra attention to when cleaning, and if using a high pressure washer, be sure to hit these areas at multiple angles.
How Fast Does Rust Spread?
To spread, rust requires the same three elements mentioned at the beginning of the article (an anode, cathode, and an electrolyte). What causes spreading is water getting under the adjacent protective coating or paintwork of a rust affected area and finding its way into neighboring areas already compromised by a missing sealant or protective coating.
The only way to stop rust from spreading is to have the rust removed, or completely seal around the area to prevent water from entering. A small bubble or pinhole is an early warning sign that rust is beginning to take hold.
How much time you have to repair the rust before things get serious depend on a number of factors including average air temperature and humidity at your location, how clean the metal is, how many contaminants are in the metal and the composition of the steel. Only a professional will be able to give you a true assessment of how bad your rust problem is.
How To Stop Rust From Destroying Your Car
Your car rolled off the assembly line with a layer of rust protection built in. The car’s paint acts as a seal and prevents moisture from reaching metal in the bodywork. Keeping your paintwork in excellent condition prevents rust from becoming a problem (and keeps your car looking good!).
Make The Car Wash Your Best Friend
Sounds counterproductive, but the best way to prevent rust is with more water. Don’t wait for your car to get visibly dirty because some elements that attack your cars paintwork aren’t visible to the naked eye.
Any method for washing your car is better than not washing it at all, but the best way is with a high-pressure cleaner. These make it easy to clean difficult to reach spots like inside wheel arches and those tricky corners in the undercarriage. Schedule some time to wash your car regularly. Try to wash it once a week and get it professionally cleaned once every two months.
Give Your A Regular Once Over
As you’re washing the vehicle, keep your eyes open for any rust or damage to the paint that has exposed the metal body. Pay particular attention to the condition of any seals, water channels, and drain holes. When these don’t work the way they should, it can easily lead to rust issues.
Get Car Rust Repaired Before It Spreads
Once you’ve identified a potential problem or the early signs of rust, getting it fixed before it’s had a chance to spread will save you hundreds or possibly thousands of dollars later. The more rust in a vehicle, the more hours it takes to repair, and it doesn’t take long to put a serious dent in your bank account.
Use An Anti-Rust Coating
Car manufacturers use several layers of rust protection, and you can even buy some off the shelf. If you’re having rust problems, or live in a harsh environment, a professionally applied rust protective coating can practically eliminate potential rust issues.
The Takeaway
Rust only requires a few elements to come together and rapidly send a vehicle to the scrap heap. Maintaining your vehicles paintwork, inspecting your car regularly, and sticking to a washing and waxing schedule can prevent most rust problems. If you live in a particularly humid environment or have to deal with sea or road salt, a professional applied rust preventative coating can save you thousands of dollars and extend the life of your vehicle by years.