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Best Rust Prevention Sprays For Cars In 2019: Reviews & Buying Guide

Corrosion can be one of the most dangerous threats to our vehicles. It can spread unnoticed in locations you don’t see, such as the underbody of your car.

When it comes to automobile maintenance, you should make rust prevention a top priority – but in reality, this is one of the most neglected aspects of car care among car owners.

Fortunately, there is a wide range of rust proofing spray products on the market today that strive to help with this exact issue.

In this article, you’re going to learn all about the benefits of using rust proofing sprays, as well as how they exactly work.

Shiny looking side of a grey car

We’ll let you in on what you need to consider when buying these products, so that you can be sure you’re choosing the best rust proofing spray for your vehicle.

You’ll also get familiar with the various types available, what makes each one unique, and which one is most suitable for you and your ride.

Finally, we’ve reviewed our top recommended brands for your convenience.

Ready to protect your vehicle from rusting? Let’s begin!

Quick Links to Our Top Recommendations for the Best Rust Prevention Sprays

Note: Clicking the above links will take you to further information, current prices and customer reviews on Amazon.

What Are Rust Prevention Sprays? And How Do They Work?

These are products that inhibit rust from forming on your vehicle. You apply them to areas that are prone to corrosion, such as the undercarriage.

This form of protecting is also known as an undercoating.

You can choose to have it done by your mechanic, but you should be aware that this is likely to be costly. In addition to the expense, your car may also have to spend several days out of commission.

This is because professional undercoating can be more complicated than DIY rust proofing. Professional undercoating involves drilling holes into your vehicle’s body, and then it can take time for the proofing substance to be applied and take effect.

Once applied, the active ingredients in rust proofing sprays will shield metal parts against oxidation. This is the case for both professionally applied or DIY (do-it-yourself) products – they dry into an invisible film or a thick coat, depending on the brand.

The specific formula is distinct to the manufacturer. These can include polymerized materials, such as polyurethanes. Asphalt is another substance used in rust-proofing products, due to its durability and water-resistance.

Generally speaking, any compound that can dry into a resilient coat without impacting performance can be used in these rust proofing products. Some brands contain other agents (e.g. lubricating) for added benefits.

It should also be noted that some of these products are multipurpose. These are capable of stopping existing rust from spreading, as well as preventing new occurrences.

DIY rust proofing products can come in the form of paint as well as sprays, and we’ll delve into all the different types you can choose to use on your vehicle in another section later on in this article.

Why Do Vehicles Become Rusted?

Wondering what might cause rust to form on your vehicle?

Unless it’s a plastic toy you’re driving, all vehicles can corrode in one way or another. This is because iron and iron alloys (mixes of iron and other metals) oxidize when exposed to water and oxygen.

Oxidation is a transformative chemical reaction. As an example, it turns plain old iron into hydrated iron oxide: a combination of iron, water, and oxygen.

This video sums up the science behind this process for you, as well as providing tips to help prevent corrosion:

Other factors—such as saltwater and humidity—can speed up the process. In some locations and seasons, our cars run up against these elements every single day.

Fortunately, the average modern vehicle is designed to inhibit this natural phenomenon. The paint and paint finish on your car (or trucks, RVs, etc) is more than just aesthetic. It’s formulated with additives to strengthen it in various ways.

The same is true of the substances we use inside our cars, from motor oil to fuel and coolant. You can even purchase additives separately for enhancing your oil or fuel.

Additives are compounds that have useful properties, such as UV protection or heat-resistance. For our current purposes, there are rust-inhibiting additives that you can get as well.

Most components in newer vehicles are built with rust-resistant galvanized metals. If you have an older car or an antique, though, this won’t be of much help. And for cars both old and new, harsh roads and weather conditions can provoke corrosion with time.

The undercarriage, where all the support structure is exposed, is particularly vulnerable. Additives in your oil can keep the internal circulatory system clean, but can’t do much for the pipe exteriors.

Accidents can also result in those trademark orange-red patches of rust. If your paint is scratched away, the metal underneath will eventually oxidize.

Even the most cautious drivers can’t be vigilant against each and every menace the road throws at us – something’s bound to slip by. A rock from a construction truck could chip paint away; fender benders can cause scratches.

Don’t forget that corrosion can (and does) spread if untreated. What starts off as a small spot on the bottom of your driver’s side door can start to grow underneath it and eventually become a huge problem.

A few tendrils in your wheel wells can also expand outwards with time. You get the idea—don’t ignore those reddish-orange spots or blemishes!

The Benefits of Using Rust Proofing Spray

Nearly every car owner can benefit from rustproofing products.

The costs of allowing oxidation to progress can be quite high, and should be avoided.

In the following sections, we’ve listed some of the most important reasons why you should consider investing in one of these products.

Safer Operation

This is the biggest factor that should influence your decision to rust-proof your car. Corroded parts anywhere in your vehicle can jeopardize safe operation.

When metal corrodes beyond a certain point, it begins to weaken. If it’s a moving mechanism, this means it could start to break down.

Bits and pieces falling off your car can put you, your passengers, and other drivers on the road in great danger. Anything that poses a potential danger to your vehicle’s safety is considered a risk by the National Highway Traffic Association.

Needless to say, you don’t want any mechanical components failing while your car is in motion. Can you imagine if your brakes didn’t respond as they should due to oxidation? The consequences could be fatal!

Longer Vehicle Lifespan

Cars are a long-term investment. Ideally, you want the model you paid for to last for as long as possible. If you have a classic car that you’re taking care of, its value can actually skyrocket over time.

The best way to protect vehicle lifespan is with good care and maintenance. This isn’t limited to keeping up with basic repairs or essentials such as oil changes, it also means taking measures to prevent rust problems before they begin.

Stopping corrosion from taking hold is one prime example.

Avoid Costly Repairs

There’s no reason to adopt a wait-and-hope attitude toward oxidation. Once a component has severely corroded, there’s no way to repair it.

Metal that has been eaten away can’t be restored by any product. Certain mechanisms can be prohibitively expensive to replace.

For this reason, you could avoid costly visits to your mechanic by using corrosion-inhibiting sprays before problems occur.

In addition to saving money, you’ll also save yourself the frustration of an automobile that doesn’t work as it should.

Overall Protection

As we’ve touched on in a section earlier on, the road can be quite harsh on our vehicles. As you can probably imagine, the undercarriage takes the brunt of this wear and tear.

A rust-proofing spray can keep your vehicle protected from more than just oxidation – it can also shield treated areas from abrasion.

If you live in a region with frigid winters, you’ll definitely want this protection.

Road salt that dissolves ice and snow can be particularly destructive to your car. Salt has corrosive properties and, when mixed with water, can speed up the oxidation process.

What’s the Difference Between Rust Proofing Sprays, Rust Converters, and Rust Removers?

There are many different corrosion-fighting chemicals on the market today that you can choose from, and sometimes, it can be difficult to distinguish between all of them if you’re not familiar with what each one is and what it does.

We’ve covered the best rust converters, best rust removers and more on this site, but here’s a recap of the main differences between them:

Rust Converters

First things first, let’s start with rust converters.

These are chemicals that convert the oxidization, stopping it in its tracks. The end result of the conversion is a black patch that you can prime or paint over safely.

They usually include weaker acids, such as phosphoric or tannic. Some of these converters contain inhibiting ingredients too.

These save you from having to immediately cover the treated section with paint. The chemicals should prevent corrosion reforming again.

You might have to put in some elbow grease before you use a rust converter, though. For the best possible results, as much of the oxidizing metal should be cleaned off as possible.

Rust Removers

Next up, you have rust removers.

These chemicals dissolve corrosion that already exists, breaking it down entirely. You’ll then be left with bare metal.

Most removers are formulated with acids, although non-toxic varieties exist too, in case you prefer to work with those.

Rust Prevention Products

To sum it up, all converters and removers are for treating corroded metal. For more details on the exact process, check our guide on how to remove rust from cars.

Finally, you have proofing sprays or rust spray paint—the topic of this article.

Not all of these can be applied to existing oxidation. Instead, these products are more about preventing potential rust problems from coming up in the future, rather than curing rust problems your vehicle already has right now.

What Types Of Rust Prevention Products Can I Choose From?

By now, you’re well aware of what these products can do.

It’s time to go over the different types of rust proofing products you can choose from. In this section, you’ll also find out how to determine which of these types will best suit your needs.

Professional-grade undercoating often uses specialized industrial rubber sealants. A more recent innovation is using electricity to prevent oxidation. There’s not much research to show whether these devices are useful or not yet, though.


Rust proofing prays can fall under one of three categories: dripless, drip-oil, and tar-based.

Also, they can be clear coated or colored, depending on the brand.


Drip-oil sprays have a fine consistency that allows the liquid to get everywhere it needs to go, such as between tight components and mechanisms.

As the name implies, you can expect it to drip for a while after you apply it. Again, this is to ensure the oxidation-inhibiting gets into all the tight spaces.

This type of product has one major downside to it, though: it’s messy. The formulas aren’t harmful to your vehicle, but can stain your garage or driveway. They also tend to take longer to fully dry when compared to other variations.

If you’re concerned about effectiveness above all else, drip-oil might be the best choice for you. The water-like formulation of the sprays enhances coverage. Some are able to combat surface corrosion too.


Dripless rust proofing sprays are formulated to dry shortly after application.

Typically, the applied substance begins to harden almost as soon as it’s exposed to air. This provides a layer to protect the vehicle’s components.

If you choose to go with this type, you won’t have to deal with dripping.

The tradeoff is that as these are thicker, which means they might not give you as much coverage as drip-oil does. Nooks and crannies may not get a thorough dose, unless you’re vigilant or can get your car on a ramp.


Tar-based rust proofing sprays use a substance with properties similar to tar: thick and rubbery. Examples of ingredients include materials such as rubber or latex.

As with dripless products, tar-like rust inhibitors will harden after exposure. They form a tough shield against salt, water, and other harmful debris.

The problem with this type, though, is that you have to be very careful with application. Otherwise, the hard shell can crack, which ultimately defeats the purpose of applying it in the first place.

As long as you have a clear shot at the treated areas, they should hold up pretty well.

Note that, for most brands, any traces of existing oxidation will have to be thoroughly removed before application. If not, the metal can continue to corrode out of sight.


Rust proofing paints can be viscous and hard-drying, or water-like in consistency. Depending on what you’re aiming to protect, they can be a great option.

For example, say you have a large section that you can easily access, such as the bed of a truck. In this case, paint might be a great choice. Owners of larger vehicles may also prefer paint rather than buying multiple spray cans.

Paints can also come in different colors. If you want to use it on your vehicle’s body, you can pick a shade that matches your paint job. Even if it’s not a perfect match, you may be able to get pretty close.

As with dripless and tar-based types, paint can be hit or miss. If you’re not meticulous, you could end up with areas that don’t get coated.

Paint can also be more of a challenge to use, so be prepared to get your brush or rollers out. With a spray can, you don’t have to do much, apart from aim and hold the nozzle down.

Paint Vs. Spray – What’s the Difference?

The difference between rust proofing paint and rust proofing spray is all about the method of application and packaging. As a matter of fact, sprays and paints can share similar oxidation-preventing ingredients.

Paints can have more diversity in terms of color, while sprays are generally limited to clear coat or black. Also, you’ll usually get a larger quantity of product with paint.

With sprays, on the other hand, everything you need is the can itself. Paints need equipment such as brushes, and possibly require more clean up afterward.

Buyer’s Guide – How to Choose the Best Rust Proofing Spray

There are quite a few considerations to bear in mind before you buy anything for rust proofing your vehicle.

You want to be sure you pick a product that works well for you as well as your automobile, so take note of the following:


Consider what you’re going to be applying the substance on, and check the product guidelines to make sure the product you’re thinking of buying is compatible.

Will it work on all sorts of metal or just on particular types? Will it damage surrounding materials such as plastic trim, or potentially affect your vehicle’s paint?

These are all important factors to consider before making a purchase.

Size of Area to Treat

Automobiles come in all sort of different shapes and sizes. A small can might be fine for a Mini Cooper, but not for a Jeep.

Many of these products will at least give you an estimate of how much they can treat, so pay attention to that.

Be sure you get the right quantity for the job at hand. You don’t want to be caught with only half your car treated and no more product left in the can for the other half!

Vehicle Condition

If you do have degrading spots on your vehicle, choose carefully. Not all proofing liquids can be applied to metal that’s already corroded.

If you don’t want to scrub or sand it off, select a product that can halt oxidation.


Review our section above where we discuss the different types of rust proofing sprays (and rust proofing products in general) to find out which type works best for you.

As a reminder, those of you who are particularly concerned about stains on your floor may want to choose tar-based or dripless liquid, or paint.

It’s worth repeating that if your concern is ultimately the most comprehensive treatment, a drip-oil is best in that case.

With that being said, there are advantages and disadvantages to each type, and no single one is right for all vehicle owners. Your priorities matter!

What Else Can It Do?

Remember we mentioned that some products are multi-purpose?

A few good questions to ask yourself before buying any rust proofing spray are: Does the formula have additional ingredients such as lubricants? Is it resistant to sub zero or extremely hot temperatures?

Know what it can do, and how this aligns with your needs.


How long can you go between applications? Ideally, you want the rust-inhibiting action to last for as long as possible.

This may seem obvious, but remember that the longer it lasts, the less often you’ll need to worry about problems.


Because they contain chemicals of all sorts, many types of automotive products can be toxic, and rust-proofing sprays are no exception.

Such chemicals can cause burns or respiratory distress if inhaled. So, be sure to read the label to know if you’ll have to wear protective clothing or wear a mask while using a specific rust proofing spray you’re thinking of buying.

You should also be aware about whether or not you may need to use it in a well-ventilated area.

This could be difficult if you don’t have a suitable indoor work-space and are in a region prone to adverse weather conditions. In this case, make sure that the season is conducive to outside work.


Preserving the environment is an important consideration for many of us these days.

If you prioritize eco-friendliness, this is another reason to avoid toxic products if you can. In addition, it would be best if you look for rust proofing products that are also biodegradable.

Drying Time

Remember that certain types, such as drip-oil, take longer to dry. If your chosen brand has a longer drying time, you need to have a plan in place.

Your car might be out of action for several hours, or even a few days. Driving it too soon could mean you waste both time and money, so you’ll need to have an alternative transportation method at the ready for the meantime.


This is for those of you who really care about how your car looks at all times.

If you’re using a colored paint, is it a near match to your original color? Will it leave a smooth surface when dry? Will a clear-coat liquid leave any residue that will look unsightly?

All of these questions – and more – are important to ask.

Best Rust Prevention Sprays – A Detailed Look at Our Top Recommendations

By now, you should be ready to choose a rust proofing spray to protect your car against corrosion, and get a better idea about which will suit you best.

We’ve simplified things for you by listing our top recommended products on the market, as well as talk about the advantages (and potential drawbacks) of each.

POR-15 Rust Preventative Coating

POR-15 45404 Rust Preventive Coating Semi-Gloss Black - 1 quart

If your vehicle is showing signs of rust and corrosion, POR-15 may appeal to you. This paint can be applied on existing rust patches.

You won’t have to exhaust yourself cleaning corroded metal, but note that preparing the surfaces you want to treat will always give a better finish.

You should also be aware that this is a colored paint. If you want to spruce up your truck bed or undercarriage, this product will likely do the trick, and the finished result will be smooth and sleek.

Users of any level of expertise can paint this substance on, thanks to its thin consistency.

Any standard paint brush will allow you to get the product on smoothly. An added benefit is that a little goes a long way, and you won’t need to go overboard and waste liquid.

It can also be used in a spray gun, thinned down by 5 percent if needed, using POR-15 solvent. However, the spray gun must be cleaned immediately after use, before the paint has a chance to dry.

Once applied, it will dry into a hard-wearing gloss, and this will prevent the corrosion from expanding any further. It will be sealed permanently into place.

This hard shellac will protect non-corroded metal surfaces too. It’ll dry almost instantly after being brushed on.

One of the main advantages that POR-15 has to offer is durability.

Once it’s dry, you won’t have to be concerned about cracking or chipping. It’s non-porous to inhibit moisture from seeping in and causing oxidation, and you can expect it to stay on for a long time to come.

Manufacturer’s Specs and Features

  • Available in 1-quart and 1-pint cans.
  • Black paint.
  • Compatible with metal substrates.
  • Permanent.
  • Seals existing corrosion.

What We Like

  • No need to scrub away existing rust.
  • Durable seal.
  • Glossy black finish.
  • Non-porous.
  • Easy to apply.
  • Dries rapidly.
  • Can stop oxidation escalating.
  • Can be used with a spray gun.
  • Great for underside of vehicles.
  • Protective coating.

What We Don’t Like

  • Sensitive to UV light.
  • Toxic—be sure to use it in a well-ventilated area, and wear protective gear.
  • Possibility of facing difficulties resealing the can.


Use POR-15 if you want a quick and simple rust-proofing experience.

The black finish is attractive, and it works pretty well to stop corroding patches from expanding. Apply using a brush or spray gun, but don’t use it in enclosed spaces, though.

You can learn more about this tough product at the link below:


Click to Learn More / Buy from Amazon


BOESHIELD T-9 Rust & Corrosion Protection/Inhibitor

BOESHIELD T-9 Rust & Corrosion Protection/Inhibitor and Waterproof Lubrication, 12 oz.

This dripless spray was originally developed as a solution to use on aircraft components. It’s ideal for those of you who are looking for more than just a corrosion-inhibitor.

Boeshield T9 can be used for multiple purposes, targeting and breaking down existing oxidation.

It serves as a lubricant, meaning it can be used on squeaky doors. This also means it can loosen corroded mechanisms. The formula can also flush out traces of old lubricants caught between moving parts.

Although it’s dripless, this waxy substance is designed to be penetrative. It will remain liquid long enough to seep into tight spaces.

By the time it dries, the liquid should be covering everything it needs to protect. The film isn’t sticky, so it won’t attract debris or dirt.

You can also apply it almost anywhere on your car, as the spray won’t harm plastic trim, vinyl, or your paint job.

Spray it inside your engine or even on your electronics (e.g. wires). T-9 isn’t made from conductive ingredients, so it won’t cause short circuits. The film is waterproof, so washing your vehicle won’t wear the product away.

If you need to get this substance off for whatever reason, there’s no need to panic, as a standard solvent or emulsifying cleaner should remove Boeshield T-9 quite easily.

Manufacturer’s Specs and Features

  • Can capacity: 12 ounces.
  • May be available in other sizes.
  • Dripless spray.
  • Compatible with many surfaces: metal, paint, vinyl, and plastics.
  • Suitable for use on existing corrosion.
  • Waterproof.
  • Acts as a lubricant.

What We Like

  • Developed for aircraft components.
  • Won’t damage non-metal or painted components.
  • Includes lubricants.
  • Resilient.
  • Can be used on existing rust.
  • Versatile applications.
  • Simple to remove on surrounding areas.
  • Mess free.

What We Don’t Like

  • Spray nozzle tends to block easily, but running it under hot water seems to resolve the problem.


BOESHIELD T-9 is a multipurpose product that’s straightforward to use. You can also rest assured it won’t stain anything or damage non-metal parts.

If you’re interested in purchasing a can or two for your vehicle, then follow this link:


Click to Learn More / Buy from Amazon


Fluid Film Powerful Rust & Corrosion Protection

Fluid Film FLUIAS11 Lubricant/Corrosion Inhibitor, 11.75 oz, 12', Orange

Fluid Film is another dripless spray that can inhibit the progression of rust and protect against further corrosion.

The non-toxic formula is made with lanolin, also known as wool-wax. This makes it eco-friendly and safe for use on the majority of plastic as well as painted surfaces.

This product is a potent weapon against rust, and it’s even capable of stopping pitting from growing worse on chrome surfaces.

Because the film it creates is fluid rather than solid, there’s no concern over cracking or chipping. This fluid quality also makes it a great lubricant for the moving mechanisms in your car.

But that’s not all – there’s another advantage to the consistency of this product: It’s liquid enough to get into hard to reach spaces, ones that thicker liquids cannot. So, you can rest assured it will spread everywhere possible.

It’s non-conductive, which means you can use it without worry on your battery terminals to inhibit oxidation. The consistency is thin enough so that it won’t turn to gunk, while remaining a strong and effective choice.

This shield will stop nasty compounds such as road salt from sticking to your undercarriage. It won’t freeze when the temperatures drop either – instead, it’ll remain active all through the winter months.

If you live in a harsh winter climate, there’s even more good news for you: Users who deal with ice and snow buildup will appreciate Fluid Film.

One of the designated purposes of this spray is to actually protect winter equipment. It contains agents that inhibit snow and ice from sticking to metal surfaces, so applying it could mean no more icicles to crack off your vehicle during winter mornings.

Manufacturer’s Specs and Features

  • Can capacity: 11.75 ounces.
  • May be available in other sizes.
  • Dripless spray.
  • Compatible with all metal surfaces.
  • Suitable for use on existing corrosion.
  • Won’t harm most plastics and paints.
  • Non-toxic.
  • Eco-friendly.
  • Acts as a lubricant.

What We Like

  • Can be used throughout your vehicle and home.
  • Lubricating properties.
  • Long-lasting rust protection.
  • Non-toxic and environmentally friendly.
  • Repels ice.
  • Stops corrosion from progressing.
  • Effective on pitting.
  • Spreads throughout nooks and crannies.

What We Don’t Like

  • Might soften existing undercoating in certain vehicles.
  • May not last long under harsh conditions (e.g. prolonged exposure to road salt).


This product can effectively stop oxidation and protect your vehicle from further threats. It also contains agents that make it a great choice for bitter winters.

You can take a closer look at Fluid Film for yourself at the link below:


Click to Learn More / Buy from Amazon


CRC Marine Heavy Duty Corrosion Inhibitor

CRC 06026 Heavy Duty Corrosion Inhibitor, 10 Wt Oz

Living in a balmy, humid climate or by the sea is surely lovely – but unfortunately, it’s much less healthy for our vehicles than it is for most people. To be more precise, salt and humidity are two of the primary environmental causes of corrosion.

This heavy-duty dripless spray is designed to withstand these exact conditions.

It can be applied to your engine components, electrical connections, and metal surfaces. This means it can provide vehicle-wide protection against oxidation.

Another positive feature is that it’s waterproof. Trips through the car wash or a bout of stormy weather won’t necessitate another treatment.

Once you spray it on, the liquid will dry to a waxy film. It doesn’t dry instantly, so it can penetrate deeper into the treated areas.

All these attributes make it great for winter protection, too. The resilient film will shield your vehicle’s undercarriage from road salt and everyday exposure to moisture (such as snow).

You’ll be able to protect more than just your car from corrosion, too. For example, you can use this product on your off-road or marine vehicles and equipment as well.

If using on visible areas, be aware that this is product is a light brown color.

Manufacturer’s Specs and Features

  • Bottle capacity: 10 ounces.
  • Available as a package of one, four, or six cans.
  • Dripless spray.
  • Suitable for use on existing corrosion.
  • Resistant to salt-spray and high humidity.
  • Compatible with metal surfaces, engine components, electrical connections, and more.

What We Like

  • Ideal for humid climates.
  • Protects vehicles close to the sea.
  • Multiple uses (e.g. boats).
  • Waterproof.
  • Sustainable.
  • Reaches nooks and crannies.
  • Can treat surfaces throughout your car.

What We Don’t Like

  • Might leave visible residue on some surfaces.
  • Spray nozzles tend to block easily.
  • Not a clear liquid, leaves a light brown color.


If you’re living in a humid climate, CRC Marine is an ideal choice to inhibit corrosion on your vehicle. The same goes for those of you who live by bodies of saltwater.

It’s long-lasting and can be used nearly everywhere on your automobile, but the color may not be suitable on visible areas.

You can get it for yourself by clicking the link below:


Click to Learn More / Buy from Amazon


3M Professional Grade Rubberized Undercoating Spray

3M Professional Grade Rubberized Undercoating, Corrosion, Water and Salt Spray Resistant, 16 oz, 1 aerosol

This product can act as a potential alternative to a professional car undercoating. As the name suggests, it dries into a durable rubber coat once applied.

You can use it on all exposed metal surfaces on your vehicle that are susceptible to oxidation – this includes your wheel wells, under the hood, interior fenders, etc .. you get the idea.

The aerosol can is nearly effortless to use. You won’t have to soak the area you’re targeting, and just one coat should be enough.

It won’t sag or drip as you’re spraying it out, either. Make sure to keep the can steady and you’ll get a uniform, mess-free coating.

A big benefit that this dripless spray has to offer is the final result. The finished product is a black, flat finish. Even if you’re the only one who will notice the change (and this is usually far from the truth), a spruced up vehicle is always pleasant to look at.

The rubberized coat itself is chip and flake resistant. It’ll hold up as a barrier against everyday menaces such as moisture, dust and inclement weather that encourage oxidation. The thick rubbery layer will repel grit and grime too.

The spray is asphalt-based, so you can expect it to last for quite a while.

Last but not least, this undercoating will do more than just resist corrosion – it also has sound-deadening properties. This means that after treatment, you should hear less road noise than you’re accustomed to, which is a great added benefit to many drivers.

Manufacturer’s Specs and Features

  • Can capacity: 16 ounces.
  • Available in packages of one can through five cans.
  • Dripless tar-based aerosol spray, black.
  • Compatible with most metal surfaces.
  • Suitable for use on existing corrosion.
  • Rubberized formula undercoating.
  • Aerosol dispenser.
  • Includes sound-deadening agents.

What We Like

  • Reduces road noise.
  • Smooth matte finish.
  • Won’t chip or flake off.
  • No mess.
  • Stops existing corrosion.
  • Well-known manufacturer.
  • Requires only one coat.

What We Don’t Like

  • Multiple cans required to treat the average car.
  • Black finish might be suitable for some applications.
  • Protective mask and gloves must be worn.


This professional-grade product by 3M is an attractive choice for treating exposed metal on your vehicle. It also has aesthetic, as well as protective applications on black surfaces.

You can learn more about 3M professional grade rubberized undercoating here:


Click to Learn More / Buy from Amazon


Rust Bullet Automotive Rust Inhibitor Paint

RUST BULLET Automotive Rust Inhibitor Paint, 1 Quart

This tough metallic grey paint by Rust Bullet has a range of enticing features.

First things first, users with vehicles that are metallic grey won’t have to use a topcoat with this product. It’ll protect the bare metal against UV light and scratches, as well as oxidation.

The formula also does a good job at preventing the spread of existing corrosion.

Minor-to-moderate patches can be painted over directly; just get rid of loose flakes before applying it. This makes it convenient for those metal surfaces that are already corroding.

You can use it on steel or iron, regardless of whether it’s painted or unpainted.

As we’ve already mentioned, this paint is made to last. You’ll want to be careful while you’re applying it, though—as this substance doesn’t come off easily.

It has strong adhesion and sealing properties, and oxidation trapped underneath it won’t be able to bubble through or bleed out.

The upside is that you’ll know for a fact that your car will be well-protected.

Once dried, the metallic grey finish won’t chip or flake off. It also provides a decent base for a topcoat to be applied over it, although this isn’t required.

A small quantity will go further than you would think. One quart of Rust Bullet can cover up to 100 square feet of surface area.

It can be applied with a spray gun, roller or brush – so you have multiple methods of application to go with, depending on which you’re most comfortable using.

Manufacturer’s Specs and Features

  • Can capacity: 1 quart.
  • Also available in 1-pint, ¼-pintand 1-gallon sizes, in single or multi-packs.
  • 1 quart covers up to 100 square feet.
  • Can be applied over unpainted or painted iron and steel surfaces.
  • Suitable for use on existing corrosion.
  • Metallic grey paint.
  • UV resistant.
  • 72-hour cure time.

What We Like

  • Stops oxidation from spreading.
  • Long-lasting.
  • Doesn’t require a topcoat.
  • Scratch resistant.
  • Smooth finish.
  • Minimal preparation.
  • Can be sprayed, brushed, or rolled on.
  • Generous coverage.

What We Don’t Like

  • Minimum of two coats required.
  • Recommended 72-hour cure time, which might be more time than some people are willing to spend.
  • Difficult to store open cans for long periods of time.
  • Toxic—protective gear is a must.


Users looking for a product that will withstand the test of time may be interested in buying this Rust Bullet automotive rust inhibitor.

Treatment is convenient, and you won’t need gallons and gallons to treat your automobile. Remember to wear protective clothing when using, though!

If you’d like to buy a quart or more for yourself, you can do so at the following link:


Click to Learn More / Buy from Amazon


Permatex Rust Treatment

Permatex 81849 Rust Treatment, 10.25 oz. net Aerosol Can

This treatment is suitable for users with specific rust-proofing needs, but it’s also appropriate for those who have already treated the bulk of their vehicles (e.g. undercarriage).

It’s great for treating surfaces that won’t get super-heated, such as your wheel wells.

If you want to target corroded metal on your vehicle’s bodywork, Permatex is certainly a good choice to consider. You can paint over it directly without having to use a primer.

The formula uses polymer-based ingredients to form a seal over existing rust, and you’ll know that the spray is effective when the affected area turns black.

If you have scratches or chips that have resulted in bare metal being exposed, Permatex will help protect against corrosion.

You can use it as insurance against oxidation before painting over these spots, and this will guarantee that if degradation has started in any form, it shouldn’t escalate any further.

Although it’s a spray, you can adapt the application method to meet your needs. You can spray the liquid into a container and use a fine brush for precision – it’s a spray that can also be painted on.

A maximum of three coats should be enough to tackle minor to moderate corrosion. Preparation is also minimal: all you’ll need to do is clean the area of dirt and debris before getting started.

Since the liquid doesn’t dry instantly, you’ll have more than enough time to correct any unintended errors (if you made any).

If you do accidentally get any of this product on surrounding areas (e.g. plastic or fiberglass), you can simply wipe it off.

Manufacturer’s Specs and Features

  • Can capacity: 10.25 ounces
  • Available as one can or a pack of 12.
  • Also available in 8-ounce or 16-ounce cans.
  • Liquid spray.
  • Converts existing rust.
  • Compatible with metal surfaces.
  • Acts as a paint primer.
  • 24-hour drying time.

What We Like

  • Prevents minor to moderate corrosion from escalating.
  • No topcoat needed.
  • Serves as a primer.
  • Best used to rust proof smaller areas.
  • Prevents oxidation from recurring.
  • Can be sprayed directly or applied with a paint brush.
  • Won’t stain paint or other materials if removed immediately.

What We Don’t Like

  • Quite ineffective at temperatures exceeding 200 degrees Fahrenheit.
  • Takes up to 24 hours to fully cure.
  • Incompatible for use on exterior sheet metal repairs.


Permatex rust treatment is perfect for users wanting to target corrosion on fixed areas. It will stop oxidation from returning, and can be painted over without needing a top coat.

You can get a can for yourself by clicking here:


Click to Learn More / Buy from Amazon



Don’t underestimate the power of preemptive action when it comes to your vehicle!

By being proactive and not reactive about stuff like this, you can save yourself grief, expense, and effort later on by rust-proofing your car or truck now.

Remember that no automobile is immune to corrosion, no matter how new or well-cared for it is. Hopefully, you’ve found the best rust-proofing spray for your needs among our reviewed products.

If you have feedback or any questions you’d like to ask, be sure to drop us a line. We’d love to hear your thoughts in the comments, and as always – we’ll respond to each and every one of you in due time!


Product image credits: © Amazon.com

Please be aware this page contains affiliate links and VehicleScene.com receives a small commission if you purchase anything after clicking through such links. This has no effect at all on the eventual price you pay.

Kyle Palmer

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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