Can you fix rust under a car?

More often than not, rust can be fixed. There are great differences between some cases of rust, and some of them might just require a slight touch-up, while others might require lots of bodywork. Some rusty cars even require completely new car panels.

So it’s not a question of is it possible, but does it make sense to fix a corroded car? Grinding out a corroded area and sanding it down costs way less compared to panel welding and replacement. So a rusted car is only worth repairing if financially feasible.

A rusted car can also be a huge problem waiting to happen, especially so if the frame of the car is rusty.  The structural integrity of the car is compromised, and the car can literally break in half. These levels of rust are usually not worth fixing at any cost.

It’s safe to say that if you do not own a special limited edition highly valuable car that might benefit from a top-down bolt and nuts restoration, fixing any serious rust is pointless. Non-special cars with large rust spots are usually older and less likely to retain any value afterward.

Fixing smaller rusty spots

Smaller rusty spots are fairly common with cars that are 20+ years old. Lots of these cars are not made with any rust protection from the factory, and they are even expected to rust if no proactive measures were taken.

First, you should locate all the possible rust spots, and for this, it’s probably the best idea to take the car in for an inspection. After you’ve successfully located all the rust spots, go ahead and buy all the necessary equipment needed, such as fine-grade sandpaper, a grinder, paint primer, a can of black automotive paint, and a high-quality degreaser.

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Furthermore, you should also buy the appropriate protective equipment such as a pair of decent protective goggles and gloves. Moreover, a car hoist or a quick jack is also a good idea since the rust is likely located on the underside of the car.

First, you should clean the rusty spot, grind it down and finish the prep work by sanding down the surface to bare metal. After you’ve successfully got rid of all the rust, you should prime the area, and wait for the primer to dry. After that, go ahead and paint the area.

How To Remove Rust From Bikes - Bea...
How To Remove Rust From Bikes - Beau Turner Youth Conservation Center

Proactive rust-proofing measures

After you painted the area, it’s also a good thing to take some proactive measures to ensure that rust is less likely to happen. A natural next step after the process highlighted in the previous section is to use a tar-based substance also known as an undercoat to further protect the vulnerable areas.

This substance is made to create a protective layer between the paint and the elements, and if applied successfully should protect the panel for a year or two. This process usually costs $100-200 and should be repeated every year or two.

You should also check out a variety of different oil sprays also made to protect the panels from rusting. These can be had in drip or dripless forms, but the dripless ones require you to drill into your car’s panels, which is never a good idea. Both of these are also priced similarly to the tar-based coating.

You can also check out a dedicated electronic module that if placed strategically send out a constant electrical current throughout the car’s body, and makes it theoretically impossible for rust to occur. But these are primarily made for boats and under surfaces that are constantly submerged, otherwise, they are not as effective, and they cost a few hundred dollars as well.

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Fixing serious rust

All of the aforementioned rusty spots can be and are fixed fairly often. But, if your car has lots of rust spots, or the levels of existing rust spots are more severe, then it’s a lot harder to fix it. If your panel is completely rusted, there is nothing you can do to save it.

This means that you are likely looking at a brand new panel, and if the rust has spread to other panels as well (which is often the case), you are also going to need all the additional panels. These repair jobs can cost a lot of money, and it takes an experienced mechanic and a great bit of time.

If there is severe rust on your structural parts, then it’s pretty much game over because these fixes require you to disassemble the car completely. It’s worth mentioning that almost all corrosion can be fixed in one way or the other, but some levels are reasonably beyond repair.

FAQ Section

Should I fix the rust on my car?

It depends on the rust, the car in question, and you. If the rusty spots are small and easy to get to, then go ahead and fix it. If the rust spots are large and severe, then it does not make all that much sense if the car is not worth anything.

If you own a classic 911 for example or any other valuable car, then it might make sense to fix the car. And it also depends on what you want. If you love your car and hate to see it go this way, go ahead and repair it, but only if it makes some financial sense in the end.

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How often does rust occur?

On modern-day cars, rust is not all that common thanks to a lot of rust protecting methods and proactive factory measures. Furthermore, loads of newer cars are also under warranty for a large variety of damages including rust.

Older, heavily used and battered cars are much more prone to corrosion. Unpaved roads, stone chipping, salt, and prolonged moisture exposures can progress rust into serious issues, so always make sure to check the car every once in a while.

Does it make sense to save a completely rusted car?

A completely rusted car is a car with loads of severe rust spots and even a bunch of structural body rust. These are not worth repairing in 99% of cases. But, if the car in question is a limited edition, highly sought-after classic, then it might even make sense.

A couple of years ago, a man found a 60s Ferrari 250 GTO literally buried in his backyard. The car has completely rusted out, but after the restoration, the car’s value skyrocketed to several tens of millions of dollars.

Marko Mikulic

Why do you love writing about cars? I love writing about cars as cars are a huge personal interest of mine. I was raised in a car enthusiast community and ever since I was young, I always wanted to do car-related work.

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