LAST UPDATED: September 11, 2019
Best Rust Prevention Spray for Cars: Boost Your Car’s Lifespan
A rusting car is an eyesore, so protect it with these rust prevention sprays
The Review Team
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PUBLISHED ON September 11, 2019
Every time you take your car out for a drive, you subject it to weather elements that depreciate its value. Maintenance costs can weigh you down, especially when you’re dealing with serious issues, such as rust. Fortunately, you can mitigate these costs by making small changes, like getting the best rust prevention spray for cars. This review will guide you in choosing the best rust prevention sprays that will keep your car in tip-top condition.
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Benefits of Rust Prevention Spray
- Saves money. Rust can cause serious problems with your vehicle, and treating accumulated rust is an expensive venture. Rustproof spray for cars ensures you tackle the problem before it becomes a big financial drain.
- Maintains the resale value. Rust damages your car, lowering its value. If you protect your car against rust, you might get a better offer because it looks good and runs smoothly.
- Improves durability. Cars eventually wear down over time. Keeping your rust-free is one way to make sure it gives you great service for a long time.
- Reduces accident possibilities. Anti-corrosion spray for cars ensures that all parts of your car are well-maintained and functioning properly. If every component works as it should, chances of mechanical failure and accidents are minimized.
Types of Rust Prevention Sprays
Inhibitors are specially designed to prevent rust on surfaces. They slow down the process of oxidation, which leads to rust. They should be used before rust appears, and the best rust inhibitors for cars are a great preventive measure, especially in humid areas.
Removers are considered some of the best-rustproofing sprays for cars. This is because, unlike inhibitors, you can spray them directly on rust. They bond with rust, and the resulting substance can be washed off with soap and water. You can also use removers as inhibitors.
Primers form a base, which is a treated surface you can paint over. They are usually combined with removers to create powerful rust prevention sprays. Primers are bonding agents that create a bond between the surface beneath them and the paint applied on top. Their main job is to make the paint stick well to the surfaces.
3M was founded in 1902 as Minnesota Mining and Manufacturing Company. The discovery of a low-grade mineral transformed the company into a global innovator with brands and products in more than 10 key industries. Today, it is a hugely successful company known for products such as 3M Professional-Grade Rubberized Undercoating.
Headquartered in San Diego, Calif., the WD-40 Company was founded 65 years ago. It is a world-renowned brand that is popular for its home convenience products, especially its WD-40 line. One of its bestsellers is the WD-40 Specialist Rust-Release Penetrant Spray with Straw.
Since 1909, Permatex has been at the forefront of the automotive industry. It produces car products for both residential and commercial use. It’s a trusted brand with a presence in over 80 countries. One of its best-selling products is, without a doubt, the Permatex Rust Dissolver Gel.
Rust Prevention Spray Pricing
- $5-$10: If you are on a tight budget, this is a great place to start. A spray in this price range works as a rust converter for any metal surface.
- $11-$20: There are more options in this price range. Sprays come in 12- to 16-ounce cans and leave a clean finish.
- Over $20: Some of the best undercarriage rust protection products come in at this price point. Most rust preventers that cost over $20 can be painted over. Some manufacturers sell two or three sprays in a pack, so you get great value for your money.
Even after you apply the spray, your car remains susceptible to corrosion due to daily wear and tear. It is crucial that you look for the best rust prevention spray for cars that forms an anti-corrosion film on the applied surface. This feature is particularly important if you are a frequent off-road user.
The drying time separates the best rust stoppers for cars from the worst. After applying the spray on your car, you should give it about two hours to settle and dry. This is important if you are considering painting over the area. If the spray takes too long to dry, you may have to wait for hours—or days—before painting your car.
Some sprays offer a 3-in-1 formula: a rust remover, a primer, and paint. They are the best products to stop rust on cars. However, if you are unsure about using a multipurpose spray, you can use a basic remover, apply the primer, and paint over the surface.
- Chemical components: Rustproofing products can cause damage to your hands over time. Fortunately, there are options that use friendlier elements, such as lanolin. To steer clear of harsh chemicals, check the labels for warnings.
Best Rust Prevention Spray Reviews & Recommendations 2020
The 3M undercoating spray is one of the best undercarriage rust protection sprays for cars and trucks. One reason is that it doesn't run or sag during and after application. We also love its stand-out noise deadening feature. It is asphalt-based, something that makes it perfect for road noise control.
This pack contains six 16-ounce cans. Two of the cans are enough to cover an entire underbody, and you can store the extra ones for future use. The rust prevention spray leaves a black, glossy finish that makes your undercarriage less vulnerable to corrosion and abrasion.
The 3M undercoating is a handy product you can use on most parts of your car. But as a precautionary measure, make sure you treat the rusted areas first. Applying it over rust can trap water and cause rust to damage your car parts from the inside. The application angle is also crucial. It will dissolve if you don’t hold it at a semi-flat angle.
If you are looking for good value, the WD-40 Corrosion Inhibitor will not disappoint. A single six-ounce can cover about 10 square feet of your car, depending on your application method. It is among the best rust inhibitors for steel, as it binds to metal and safeguards it from moisture and air.
The spray forms a protective film where it’s applied and can last up to a year with above-average usage. It performs well outdoors and keeps corrosion at bay. The straw it comes with offers a controlled spray that penetrates hard-to-reach areas common in car parts. To test the true grit of the WD-40 Inhibitor, use it in humid conditions.
It performs well in all seasons, although you may need to reinforce it during winter. We also feel the can is very small and maybe insufficient for your needs. Additionally, the sticky residue the spray leaves can act as a dirt-trap.
If you are searching for the best rust prevention spray, your search may stop when you get Permatex Rust Treatment. It has an easy application process and kills rust on all automotive applications—from trucks to hatch covers. It also removes rust on agricultural equipment but can only be used on surfaces 200-degrees Fahrenheit and lower.
One of the traits that make this spray great is you can use it over rust. You will not need to apply a pre-cleaner before application. Its two main ingredients, Tannic acid, and 2-Butoxyethanol, are organic extracts. When sprayed, they form a film on the rusted surface and create a good base for painting.
But as much as it is a useful product with multiple uses, it has its drawbacks. For example, you have to give it time to completely dry. You will know it’s dry if it forms a protective coating on the sprayed area. You also need to wear the appropriate gear because it has a strong odor.
This rust and corrosion protection spray was designed by Boeing to lubricate and protect aircraft parts. It is designed for automotive, marine, and aviation use and other applications. It's safe to use on paint, metal, plastic, and vinyl. The product loosens rust, dirt, and old lubricants and dries into a thin, durable film.
This spray works well on cars, trailers, lawnmowers, and anything else that requires lubrication or protection against rust. You can spray it under the hood of your vehicles to coat anything that might rust or use it on tools, lawn mowers and snow blowers before they go into storage. It puts a great rust barrier on naked steel, goes on clear, and doesn't rub off.
The biggest complaint with this product is that while it sprays well initially, it has a tendency to clog up before you're done with the can. Also, it's a little pricey, and the finish may be a bit tacky unless you rub it down a little.
This corrosion inhibitor is for use on metal surfaces, engine parts, fasteners, and electrical connections. It provides good protection on steering and throttle linkages, spindles, motors, shafts, and more.
This product makes its way into cracks, seams, and rust, and thickens over time. While it doesn't reverse rust damage, it can stop it from spreading. It sprays evenly, lightly, and dries to a hard waxy compound. Overall, it works really well to protect against salt water, corrosion, rust, and damage.
However, the nozzle makes it challenging to use in hard-to-reach places. Also, it may leave behind a light yellow color on the surface area, which is not very attractive.
VHT's rust converter is designed to be used on rusty areas and to stop rust in its place. It's a clear spray that changes to a black metal protective coating to prevent additional rust from occurring. You can then sand the area for a smooth and even finish. It can be used on metal, fiberglass, and body filler and takes 24 hours to completely dry.
This product does what it says it will do and converts rust into a solid form of metal. After treatment, it’s easy to paint the surface area. Overall, it adheres really well, and you don’t have to do too much prep because it doesn’t affect anything that isn't rusty. Overspray does not affect the areas around it or cause any discoloring.
One downside to this product is that it runs out quickly because it comes in small cans, so you may need more than one can to complete a project. Also, the nozzle has a tendency to clog.
This rust converter stops the spread of rust and treats the metal so rust does not continue to form. It ships ready to use with a spray nozzle and can be used on anything, indoors and out, that rusts. It's safe for use on antique vehicles, farm equipment, tools, galvanized buildings, and more.
This product is perfect to use on a rusted undercarriage or suspension components. It sprays easily and covers the surface area really well. If you want to make rust inert and prevent it from spreading, this stuff does the trick. Some users have even reported that the product removes thick layers of rust.
Be aware that if you get this on your skin, it might cause some irritation. Also, you should wear safety glasses and use it in a ventilated area as it has a strong odor. It also leaves behind a white residue.
This anti-corrosion aerosol and lubricant is designed for a variety of uses related to the automotive, marine, aviation, industrial, and other industries. It comes in a 16-ounce spray can.
This product stops rust from spreading and makes it disappear. If you have a trailer hitch or rusty tools that are covered in rust, this product will stop it from growing and bring the metal back to life. It's also popular with RVers whose campers are exposed to salt from the ocean. The spray works well on engines, axles, shocks and leaf springs.
One issue is that the product has a strong odor. Also, it isn't clear, it is sticky like grease, and it can be messy to use. Another problem is the spray dispenser could be a little better quality.
- When using rust inhibitors, it is vital to know which ones require prior preparation of the rusty parts. Not all sprays can be used directly on rust. Some work as preventers while others work as treatments.
- Be sure to check whether your rust prevention spray can be used with paint. Although the sprays leave a clean finish, painting over the surface afterward might be ineffective. Also, confirm whether it's safe for bodywork.
- Always wear the right gear. Rust preventers for cars can have a strong odor that may overwhelm you. A pair of gloves and a nose cover may be very useful.
- Make sure you get extra cans. This will ensure you cover every part, and you can store any additional products for future applications.
- If you aren’t sure of the effect, test the spray on a small area first.
- Depending on the car part, you can choose the most effective application method. Spraying is the top technique, as the formula gets to all the nooks and crannies. However, there are situations when you may need to consider applying the formula using a cloth.
Q: Which is the best rust prevention product?
A: This depends on the surface. Some products are specifically made for automotive applications. However, some are multipurpose and can be used on kitchen sinks and bathtubs, too. The best rust prevention spray is one that can be used in all areas susceptible to rust.
Q: Can these rust removers be used on household products?
A: Anti-corrosion sprays for cars have harsh chemicals that might not be suitable for food-grade household items. You can use products such as CRC Calcium Lime Rust Remover to clean household items. DIY home remedies for rust removal—such as vinegar, baking soda, and acetic acid—also work well.
Q: Can rust removers be used over porous surfaces?
A: Rust prevention sprays are suitable for porous surfaces since they trap moisture. However, you will need more for the best results.
Q: Can rust inhibitors be applied on areas that get hot, such as exhaust pipes?
A: Unless stated otherwise, manufacturers do not advise applying these sprays on areas that exceed 200 degrees Fahrenheit (93 degrees Celsius).
Our pick for the best rust prevention spray for cars is the 3M Professional Grade Rubberized Undercoating (Six Pack). It works on undercarriages, fenders, floor pans, and wheel wells, and it also reduces road noise.
If you are on a budget, get the WD-40 Specialist Long-Term Corrosion Inhibitor. It can block rust and corrosion for up to a year and offers the best of both worlds: preventative maintenance and protection in corrosive environments.