Cars, especially older models that have been around for a while, are subject to rusting. Of course, depending on the climate or environment that the car spends most of its time in, the severity of the rusting varies. Usually, very harsh environments are the most damaging, such as snow or heavy fog, near an ocean for instance. The result of keeping a car in such an environment could be as detrimental as rusting right through the metal.
Fortunately, there are preventative measures you can take to mitigate the damage, it just depends on if you need it or not. If you own a brand new car, which if it came from a dealership, could already have rustproofing applied, and you live in moderate climates like the inner peninsula of California’s Bay Area, you probably don’t need to worry about it as much as someone in, say, Pacifica, CA which is right next to the ocean. So before you rust proof your car, be sure to evaluate if whether or not you actually need it at all.
Rust proofing can come in many forms but it is fundamentally a method of preventing the iron in your car’s metal body from reacting with air and water to create rust. There are many ways of having it done, and dealerships will often offer their own rust proof services for a hefty price. Whether or not it’s worth the money is debatable. Used cars that aren’t rust proofed, depending on their condition, may need it, however, might be caked in too much grime or dirt to be worth the trouble. While it’s not always necessary, rust proofing is never a bad idea.
There are a few different kinds, where some come from the factory and others are applied after the fact. The most commonly recommended is an oil-based spray, which you can apply to the car in a short amount of time. It requires holes to be drilled in various locations on the car, so the spray can work its way into dark and lonely crevices where water cannot escape from. Another kind which is less effective is the non-oil based spray, which doesn’t get into tight spaces as easily as its oil-based brethren. Dealerships offer a coating similar to bed liner, which is what coats truck beds. This is ineffective, as it can crack and essentially accelerate the rusting. Dealerships advertise this as a “lifetime” rust proofing that doesn’t need to be reapplied and will charge a fortune for. This is not advised to take advantage of.
If you bought a luxury car that came from Germany, there’s a good chance it has already been rust proofed, and so well, in fact, you never need to worry about it. German automakers use what’s called “cosmoline”, which they use to coat the outside of the car and its undercarriage. This is to prevent rusting while the cars are in storage and during transport. Before the cars are sold, the cosmoline is removed. If you own an older BMW you can sometimes spot it in very tight places. You can open your trunk and spot it through the holes on the underside of the lid, as a yellowish color. This process has proven so effective that BMW has used it for at least the past 30 years. You can buy products labeled as cosmoline but they probably won’t be nearly as effective as the factory grade.
If your car already has rust it’s probably fairly deep into the metal. At that point, the only way to truly be rid of it is to grind the rusted metal out, but be careful as this method can lead to creating holes if you grind straight through. A different way to get rid of rust is to douse it with baking soda, allowing it to sit for about an hour and then brushing it with steel wool. Rust won’t typically happen as long as the water that’s causing the rust has someplace to go and can’t sit in one spot for too long.
You can apply the rustproof material yourself, however, it might be a better idea to have a shop do it for you as they have more experience and might be more thorough. While the costs to do so varies based on the shop you use and the type of rust proofing you want to use, you can bet it’ll be less money and more effective than the dealership’s method.
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