The cost of a rust repair varies significantly from vehicle to vehicle. It depends, in short, on the build quality, the amount of metal (or exposed metal, more specifically) used for the car, and your local climate, amongst other things.
Of course, it’s also hugely related to the area that requires treatment.
Pretty much every car you can possibly buy is susceptible to rust. That’s because they’re all made of metals – and all metals rust. Scroll down to read some more about the process of rusting.
In this article, we’ll look at the cost of rust repair, why your car corrodes, and the process involved to try to fix it.
- Rust repair cost
- Why does rust form?
- What is rust?
- Aluminum usage
- Rust repair cost for DIY
- How to prevent rust
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How Much Does Rust Repair Cost?
As with many topics, it’s very difficult to tell you how much your rust repair job will cost because it’s dependent on so many factors.
- How much rust is there? And how deep does it go into the surface?
- How much work needs doing?
- Has the rust been there for a long time?
- What does the auto shop charge in terms of hourly labor rates for rust repair?
- Is the structural integrity of the chassis compromised?
- How difficult is the area of rust to get to?
- How humid is your local environment?
- Is your car exposed to a lot of salt? (You might live near the ocean or in part of the country where salt is used on roads in winter.)
- Was the car put together with a high level of build quality? Modern cars almost certainly will have been, but some older cars? Not so much.
- What metals were used in the car’s build?
- Do you need some rust-preventing work being done too?
As you can see, there’s a considerable number of factors.
As such, for minor repairs, you could pay as little as $20 or $30. Think along the lines of small, cosmetic-only rust spots for this kind of cost. Jobs that you can do yourself with no professional help.
At the other end of the spectrum, substantial structural repairs may cost well into the thousands of dollars – perhaps $2,000.
It’s pretty much impossible for me to give you an exact estimate. If you’re after a better approximation, you’ll be best phoning your local shops for quotes. Not every garage will offer rust repair services, just so you know.
Getting Quotes If You Struggle With Phone Calls
Phoning businesses up can sometimes be scary – telephobia is a genuine form of social anxiety. It’s not helped by the fact that you could be speaking to someone trying to force you to use their shop. If that’s the situation, it’s nothing to be ashamed of. You may like to consider asking a friend or relative to phone up for you or email the companies instead if they have an email address.
If you send an email, it may be best to take some pictures of what you can see. These will give the technicians a better idea of what they’re likely to have to do.
However, getting in touch with businesses is the best way to get a good approximation for your rust repair cost.
Quotes from companies may be dependent on inspection. That’s perfectly reasonable, so be aware of that. The mechanic may find, upon closer inspection, that the rust runs much deeper than you thought, in which case you’ll have to decide whether or not to continue with the job at a higher price.
What Should I Do If Rust Has Compromised The Chassis’ Strength?
It’s a classic situation that I’ve come across a few times.
I even know someone whose car went in for a service, and the chassis disintegrated. It got driven onto the ramp and lifted into the air as normal. Part of a service is to use the jack (there’s one built into the ramp) to raise the wheels and inspect them and the suspension. When the mechanic tried to jack the car up, the jack went straight through it.
When that happens, it’s – without a doubt – a hazard to life to drive it.
If rust has corrupted the chassis’ strength, the car really should be scrapped or rebuilt rather than repaired. Once it’s reached this point, it’s no longer safe to drive.
With older cars, you may be able to save the body, lifting it off the old chassis and dropping it back down onto a new one. That’s if you can afford to do that and feel a strong need to keep the car.
You can do this because, in days gone by, cars tended to be made in two parts: the chassis and the body. At the end of the production process, they were essentially bolted together, and there’s your car.
Nowadays, though, cars tend to be built as one unique item. As well as anything, this increases safety, with things such as crumple zones being much easier to engineer.
How Is The Cost For Rust Repair Broken Down?
Like any other job from an auto shop, garages will break down a rust repair job’s cost into labor and parts.
Basic spot repairs should be pretty straightforward, and most mechanics will be comfortable doing that job for you.
Bigger jobs – any kind of deep rust on the chassis, especially – may require specialist attention. If it needs expert attention, the labor rate will be higher.
Labor rates can vary from $50 per hour to $200 per hour, depending on where you live and what the shop decides to charge. Rust repair jobs could take anything from a few minutes to a few days. As a result, the amount you’ll pay for labor will vary. So. Much.
As discussed before, it’s best to get in touch with a few local shops and get some quotes from them. Those quotes will probably be dependent on an inspection. Still, it’s the closest you can hope for to get an accurate estimation.
In terms of what the mechanic will have to do physically (and, therefore, what “parts” will be included on the invoice), it depends on what’s wrong. Again, sorry, there’s not a one-for-all answer here.
If an extensive repair needs doing, they’ll have to cut away all the rotted metal and weld in a new piece. Here, you’ll need to pay for the new metal, the welding, and the labor – as a minimum.
A small repair job – for example, just surface rust on the paint – may only need sanding down and, optionally (but highly recommended), repainting it. The new paint is important because it acts as a sealant, preventing the metal from oxidizing again. Leaving it exposed will invite the rust back in immediately.
A job like this may not take so long, but you should still expect to pay a few hundred dollars for it. The labor time may still be a couple of hours, and the shop will have to match the paint color to your car accurately. As a result, it can still be reasonably expensive.
Why Does Rust Form On Cars And Other Vehicles?
Rust can form on any part of the car. This could include:
- the body,
- the paintwork,
- or the chassis.
Let’s get one thing straight. It is as good as impossible to 100% prevent rust. The best you can hope for – at least at the moment – is just to slow it down for as long as possible.
There are a few places in the world that cars don’t rust anything like as quickly. In general, these are the less humid areas and countries. If you’ve watched Rust Valley Restorers on Netflix, you’ll know what I mean. It’s well worth a watch if you have the time.
I live in the UK, an island country with humidity levels consistently between 75% and 100%. We would consider 60% humidity a very dry day. While this is something that we’re very much used to here, people from more arid parts of the world apparently often struggle when they visit due to this.
These humidity levels, combined with our unpredictable climate, make rust extremely prevalent on the cars you find here. You have to take very special measures to keep your ride rust-free.
You don’t have to park your car in a lake to get it rusting. The humidity in the air will do it for you, whether you like it or not.
Any parts of the car where cast iron or steel is exposed will inevitably lead to rust. The car’s paint is one of the main rust-prevention techniques used by carmakers. Still, it’s impossible to protect everything permanently.
Once there’s one “chink” in the armor – once the oxidization process starts on a particular surface – it’ll keep on spreading until you get it fixed.
That’s why rust forms on cars.
Let’s now think about the process of rusting to understand better what’s going on.
What Is Rusting? (On Vehicles, Specifically)
So, let’s address the general issue of rusting.
The technical term for rust is “oxidation” – the metals combining with oxygen to form an oxide compound.
Usually, what we call “rust” is a hydrated iron oxide, iron (III) hydroxide. It comes about from iron reacting with water and air. You get a lot of iron in cars from the most-used metal in the industry – steel.
4Fe + 3O2 + 6H2O → 4Fe(OH)3
- Fe = Iron
- O = Oxygen
- H = Hydrogen
Steel is an iron alloy containing small amounts of carbon (and also other elements). Car-makers use it rather than iron because it’s more robust, more malleable, and – importantly – doesn’t rust as easily.
Rusting can occur in an atmosphere where oxygen is present. This could include the air (with humidity) or water (which is hydrogen + oxygen). If you were to remove all the moisture from the air, iron wouldn’t rust. Likewise, if you put iron in water but removed all the oxygen and impurities, it also wouldn’t rust.
If there’s salt in the water, this can speed up the rusting process, as can acid rain. It’s a combustion reaction, like fire.
All metals and metal alloys rust, with gold, chromium, and platinum being the only exceptions to the rule. Even then, these metals have to be smelted down to their purest forms in order to achieve this state. They don’t react with oxygen and therefore don’t rust in the same way as all the others.
Aluminum is another metal commonly used in vehicles, especially modern ones. Manufacturers use it because it’s a good mix of both strong and lightweight. In fact, it’s thought an equivalent aluminum component will be half the weight of a steel version.
Aluminum reacts with oxygen to form aluminum oxide. However, this layer is only 4 nanometers thick (that is, four millionths of a millimeter, or “really, really thin”) and doesn’t spread into the metal or alloy. It, in itself, provides natural corrosion resistance.
Why Do Cars Use Aluminum These Days?
Although steel (galvanized) is still the primary material used in car production, aluminum is fast catching up. Copper and brass are the other two main metals you’ll find in a car, along with small quantities of a wide range of others.
Companies use aluminum for basically anything metal in the engine, including the vehicle body and frame, wiring, wheels, lights, transmission parts and housing, engine parts, air conditioner condenser and pipes, and magnets (which are used in things like speedometers).
Compared to steel, it has many advantages.
- Since aluminum is lighter than steel, the car it’s fitted to can perform better. That’s not just important for those with a lead foot. The more responsive any vehicle is, the safer and easier it is to drive.
- For the same reason, it’ll have better fuel economy and fewer harmful emissions.
- Aluminum can absorb up to twice as much energy as steel, meaning it’s safer, and the crumple zones on vehicles can be smaller.
- A lot of aluminum is recycled – nearly 90%, in fact. This means that making a car from aluminum has much less environmental impact than steel or other metals.
- The rust-resistant qualities, such as what we’ve just been talking about, mean it’s an excellent material for harsh environments. As such, it’s often favored by the military and anyone who wants their car to be hole-free.
What’s The Process Involved To Repair Rust?
As previously alluded to, there are two main ways of removing rust.
You can either sand the rust down or cut out the entire component and replace it. This gets more difficult on newer cars which are built more like one “thing”, but it’s still possible.
You may have to replace a whole body panel or a bumper, or even part of the chassis. In that case, the mechanic will need to cut away the rusted parts and weld in some replacement metal.
Will It Cost Less To Repair Rust Myself?
It will, inevitably, cost less to repair rust in a DIY job. That is, as long as you get it right the first time around.
The counterargument is that a professional job is much more likely to be long-lasting and high quality. Because of this, the extra costs may well pay themselves back over the next few years.
For a DIY rust repair, your main costs will probably be the materials you need to complete the job. Of course, you may also need to purchase some PPE, tools, and equipment if you don’t already have it.
With small surface rust spots, you’ll need materials such as fine-grain sandpaper, cleaning equipment, and color-matched paint. You’ll also need some way of applying the paint and PPE, such as a mask to prevent the inhalation of particulates and chemicals. All in all, you should probably expect to budget about $100-$200 for these.
Bigger jobs where welding is required are also possible to do in DIY form, but I wouldn’t recommend it unless you are sure you know what you’re doing. Getting something wrong here could lead to serious injury, and you must do the job to a high standard, else your car might literally break in half while you’re driving (in extreme circumstances). Some people suggest that’s “unsafe”.
If you do decide to one of these bigger jobs by yourself, you’ll need:
- A safe place to work (consider hiring professional shop space).
- A welder (of some kind).
- Sheet metal or another kind of replacement metal in the correct shape.
- Tools for cutting away the rotted metal.
- PPE – face protection to avoid arc eye, gloves, steel toe-capped boots, a mask, head protection.
- A helper.
Here’s a highly recommended video from ChrisFix to run through a full welding rust repair.
How Can I Prevent Rust?
The main way to prevent rust is to make sure all the metal has some kind of top layer to protect it from oxidizing.
You may have heard of galvanized steel. This first came to the market in the 1980s when cars began to be imported from Japan. Up to this point, it was just a sad fact of life that your steel car was going to rust, eventually.
That led to the development of electrogalvanizing – the process of bonding a layer of zinc onto the metal to help prevent rust. You can read more about the history of electrogalvanization on Wikipedia by following the link.
It took time for the automotive industry to pick up on this technique, but it’s standard practice nowadays. It’s led to more cars being more resistant to rust for longer.
The other central defense against rust is the car’s paint. It seals the metals underneath it, preventing corrosion from starting. When you use car shampoo with wax in it – or wax your vehicle separately – the wax protects the paint. This adds yet another layer of protection against moisture and other damage that could lead to body panels rusting.
To prevent rust damage, you’ll need to regularly check under the car as well as around the engine. Check for any paint damage that may be concealing rust or lead to rust in the future. In short, make sure every piece of metal is covered with a layer that protects it.
Is It Worth Paying For A Rust Repair Job?
In my view, yes, depending on what work needs doing.
- If it’s only surface rust, such as what you find on paint layers, you may be able to work on it yourself. That being said, the main area of concern, if you do this, would be the repainting. You have to make sure to get the color exactly right; otherwise, it’ll look tacky and lose resale value.
- Anything more significant than this, such as deep chassis rust, I’d recommend either paying a professional to do the work or, if it’s really bad, scrapping the car. If the car has sentimental value, you may like to have some costly structural jobs done, but, sometimes, rust is – sadly – terminal.
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