How to Remove Rust from a Car: A Thorough Step by Step Guide

All bare metal is prone to rust, the same holds true when it comes to that of your car.

The best thing you can do with your vehicle is to act fast and remove rust spots as soon as they form, since surface rust accumulates and can grow rapidly over time.

What starts out as a small problem can evolve into a very serious one if neglected over time, and we have you covered in what you need to know in this article as far as steps needed to remove rust from your car are concerned.

Red car with damaged exterior paint because of rust

Sometimes, it’s not possible to keep on top of the situation because of how serious it is, so we’ll show you what to do in case of major rust attacks as well.

You’ll also discover options when it comes to specific commercial products, which are a bit more costly than more traditional methods, but are proven to work.

We’ll also look at using a few common household products in case you’re trying to avoid purchasing any commercial products for just this task.

Whether you’re trying to fix small rust spots or major rust damage to your car, keep reading. By the end of this article, you’ll learn how to get rid of car rust and keep it off, and we’ll also give you tips to prevent this problem from happening again in the future.

What is Rust?

It’s common knowledge that rust looks like an orangish-brown coating, one that peels off of metal. But what causes rust?

Rust is the result of a chemical process called corrosion.

The three elements needed to form rust are iron, water, and oxygen. When these 3 elements react together, they create hydrated iron oxide, commonly known as rust.

There are also outside factors that can facilitate the formation of rust as well. The most common of these factors are:

  • Humidity.
  • The weather.
  • Acid rain.

Sources of Humidity

Since water is needed to create rust, the more humid the climate is, the greater the chance that rust will form on metal, which includes your car.

Being in an area that experiences heavy or frequent rain, and living close to water sources such as the ocean, a lake or a river are all factors that will increase the chance of rust formation on your vehicle.

Hot Weather

Heat also helps create rust more quickly as it speeds up chemical reactions. Usually, more rust forms in summer than in winter.

Cold Weather

Snow is a form of water, and therefore leads to corrosion.

There’s also something else to consider when the weather is cold. In locations where snow is common, road salt is used to grit most main roads and highways.

This salt avoids the danger of icy roads, but accelerates rust formation on cars.

Acid Rain

Rain promotes rust formation in general, but if it’s acid rain, the situation can worsen quickly.

The reference to acid here refers to the pH of the rain droplets, which is acidic. It is caused by sulfuric and nitric acids combining with the water molecules.

Specific Commercial Products for Rust Removal

Now that you’ve taken a mini-chemistry lesson (sorry about that!) and know all about how rust can form on your vehicle, let’s have a look at what you’ll need to fix rust damage on your car, regardless of whether it’s light or heavy.

The process of rust removal isn’t difficult in and of itself, but it takes quite a lot of time and effort, so be prepared.

You can either do this inside your garage or, if you’re outside, choose an overcast day without wind to work on this.

We’ll start with a list of commercial products that are extremely useful in removing rust from cars:

  • Masking tape or painters tape.
  • Newspapers.
  • Rust remover.
  • Rust converter.
  • Clean rags.
  • Grease and wax remover soap.
  • Sandpaper.
  • Self-etching primer.
  • Color base coat paint.
  • Paint color that is the same color as your car.
  • Clear paint.
  • Protective eyewear.
  • Gloves.

The following three items won’t be needed if you’re dealing with light to medium rust damage – they’ll only needed for heavy rust damage:

  • Dust mask.
  • Grinder with a sanding wheel.
  • Fiberglass reinforced body filler.

How to Remove Rust from a Car (Minor Damage)

Now that you know what you need and have gathered all the necessary items and equipment, let’s look at the steps needed to remove minor rust damage from your car.

Protect Yourself

Safety first! Be sure you have the necessary safety gear on before you start with any of this, and wear gloves and eye protection at all times.

Some of the products you’ll be using, such as auto-paints, are quite toxic, so make sure you don’t come into direct contact with them.

Prepare the Car Area

Use the tape for masking the car area affected by rust. Tape off a slightly larger area to work on than you need.

You want to make sure not to get any of the products, especially automotive paint or paint primer, on the wrong spot. You can use newspapers to cover up the surroundings of the masked off area to avoid mistakes.

Spray the Rust Remover

Make sure to read the directions carefully, since each product might have different steps to follow than other products.

Spray the rust remover on the affected area, and let it act for a few minutes.

Wipe off Rust

Use a clean rag to wipe off the rust. If it’s not all gone, use sandpaper to get rid of the residue.

It’s important that you don’t proceed until all of the rust is removed; the smallest residue can spread and cause further trouble.

Apply Grease and Wax Remover Soap

Clean the affected part thoroughly, then let it dry.

Use Self-Etching Primer

If you haven’t done this before, practice on a piece of cardboard first. If in doubt, follow the instructions on the tin. When you feel confident enough with the process, use it on your car.

When you want to apply primer, we recommend a light to medium coat of primer. Spray three coats on and let the primer dry for an hour.

Spray on the Color Base Paint

We suggest a lighter coat of paint than the primer. Usually, five or six coats are needed.

Make sure to wait for each coat to completely dry before you spray on another coat. This will prevent paint drops from forming. 15 to 20 minutes should be enough between layers.

Spray on the Clear Coat

Spray the final clear coat. For the best results possible, apply three to four coats, ensuring that you leave each coat to dry before moving on the next.

Now that you have a dry coat, make sure to wait at least three days before washing your car, and wait at least two to six months before waxing.

How to Remove Rust from a Car (Major Damage)

If the rust damage situation on your car is extensive, the steps below will help with the repairs.

Keep in mind that if more than 20% of any car part is heavily damaged by rust, you’ll need to replace it.

Protect Yourself First

In addition to wearing gloves and eye protection, you’ll also need to wear a dust mask.

Protecting yourself should be your number one priority whenever you handle chemicals.

Prepare the Car

You’ll still need to tape off the area you’re working on.

If you need to sand through paint and primer, cover the rest of the car too. Preserve both the car and yourself from the dust.

Remove the Rust

If the rusty area is large, you’ll need to use a grinder with a sanding wheel.

Take off all excess rust, but be careful not to apply too much pressure. You don’t want to create more damage.

Apply the Grease Remover

Clean the entire area thoroughly using grease and wax remover soap.

Without doing this, you could further damage the paintwork, and your rust repair job won’t be as efficient.

Fill in All Holes

This is the purpose of the fiberglass reinforced body filler. If the rust damage is extensive, you’ll be left with holes and depressions.

Fill everything in properly, and be prepared for this to be one long and slow process. For the most part, curing time will be affected by humidity and heat.

Warning: do not use if the outside temperature is cooler than 65 degrees Fahrenheit! Always read the instructions on the filler container, too.

Sand the Affected Area

After the fiberglass has hardened, you’ll need to sand the part of your car that has the rust damage. As you’re sanding off the paint, keep changing to finer grit sandpaper until the entire area is perfectly smooth.

Check this guide for details on exactly how to wet sand a car.

Use Self-Etching Primer

It’s a good idea to practice on some cardboard before applying the primer direct to your car. Follow the instructions on the container, and then use it on your car when you feel confident to do so.

A light to medium coating is preferred, with an application of three coats. Be sure to let the primer dry as instructed on the tin before moving on to the next step.

This product is used as a base for paint, and stops rust from forming again.

Apply the Base Paint

This is the paint of the same color as your car.

Again, we suggest at least six coats, lighter than the primer.

Allow at least 15 to 20 minutes for the paint to be completely dry before proceeding with the next coat.

Apply the Clear Coat

The clear coat is actually a protection. It protects your paint job and makes it last longer.

Three to four layers are recommended here, following the instructions on the container to the T.

Two Effective Household Products

It’s not possible to completely substitute all the products needed to remove rust from a car with just household versions, no matter how good you are.

You’ll still need to use primer and paint, for example. You can substitute the toxic rust remover if you’d like to, though.

There’s one weird trick that is proven to work on minor rust: Coca-Cola! Believe it or not, this has been a tried and tested method keep your car clean from any old, rusty regulators. Soak them overnight, and the metal will look like new the next morning.

Magic, right? Well, not really. This is because coke contains citric acid (which removes stains) and phosphoric acid (which dissolves rust). Another plus is that it is carbonated, so it breaks rust faster.

With that being said, and before you go crazy with this method, note that you cannot soak your rusty car part in a tub of coke. Instead, here’s how to use it:

  • Pour directly on the affected area.
  • Let it sit.
  • Scrub with a sponge.
  • Repeat.
  • Each time you scrub, more rust will be gone. Don’t over-do it if there’s no longer need for it, though.

Another household product you can use as rust remover is white vinegar. Again, it is the acid it contains that works against rust.

Use it in the same way as Coca-Cola. Clearly, these two products can be used only on minor rust accumulations, such as spots, and not on more serious cases of rust on cars.

Professional Help

What if you don’t want to try and remove the rust from your car yourself?

Perhaps you don’t feel confident enough in taking up such a task on your own, or you don’t have the time (or energy) to go through all these steps yourself, and would prefer to leave it up to the professionals.

There’s certainly nothing wrong with that, and you can always get the help of a professional.

If you prefer to go down that route, costs will vary greatly, from around $100 for a minor spot to over $2000 if the damage is extensive.

Consider the trade-off between your time and expense in collecting the commercial and household products we’ve mentioned, compared to the ease but higher cost of using a professional. Then, do whatever makes the most sense in your case!

Tips to Prevent the Formation of Rust on Your Car

The best way to avoid having to deal with any of this mess, besides having to resort to using a rust preventive, is to try your best to prevent rust from forming on your car in the first place.

Here are a few helpful tips you should keep in mind:

  • Park in a garage.
  • If the car is stored outside, use a cover for protection.
  • Remove salt from your car in winter.
  • Add a coat of wax to your car before winter for protection.
  • Check the body of your car regularly for rust.
  • Take care of any spot rust immediately.

Final Thoughts

We’ve seen what rust is and what to do if it attacks your car.

We’ve given you the steps to solve this problem, whether it is only a few rust spots or major damage on your car.

We’ve also shared a few effective tricks to help you avoid this from happening again in the future. One less car maintenance task to worry about is always a win in our book!

So, you should be all set!

Before we sign off, keep in mind that the best way to avoid major rust damage on your car is to take care of any spots right away and as soon as they begin to form.

It’s not difficult to do this by yourself, but it does require time and patience. And, just in case you don’t have the time, patience or effort required to remove rust from your car on your own, you can always hire a professional to do it for you!

From childhood go karting and motocross, to collecting and obsessing over scalextric, matchbox and radio controlled cars, I've always had an obsession with cars. Learning through manuals, books, trial and error, and more knowledgeable family members, I've also enjoyed tinkering with the mechanics and electronics of any vehicles I've owned. Now, over 3 decades later, I've started this site as a place for me to share my knowledge, to teach others how to care for and maintain their vehicles themselves, at home, so they can get the most of their vehicles and save a pretty penny compared to always seeking out professional help.

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