Ferrari Dino 246GT

Fighting the breakdown: Best Rust Prevention Spray for Cars

Rust is one of the biggest problems we face in car care. In fact, it is so bad that we refer to it as “cancer.” Rust is a relentless predator that hunts down any metal in your car and destroys it. Fortunately using the best rust prevention spray for car will help you avoid the growth of this automobile cancer.

Rust begins as small bubbles or chips, but if left unchecked it will quickly turn into full holes in the panels and frame of your motorized companion. The best course of action is prevention, so I put together this guide for the best rust prevention spray for cars to help others avoid the pain I have faced from invading rust.


Name Size Rating
Eastwood 12515Z Internal Frame Coating Rust 14 oz
POR-15 Chassis Black Top Coat 14 oz
Transtar Amber Rustproofing 17 oz
Krylon Rust Tough Enamel 12 oz

Eastwood 12515Z Internal Frame Coating Rust

Best Rust Prevention Spray for CarsThe Eastwood rust spray is your go-to spray to help repair and restore the areas of your car that have been already been accumulating rust and corrosion. Eastwood uses a phenolic resin that penetrates deep into pits and rust to seal worrisome areas and actually converts rust. The penetration power of the resin actually gets deep into the metal and frame of your car to repair rust that isn’t visible on the surface. >>> Check price on Amazon

The Eastwood spray is designed primarily to coat and treat the skeletal chassis of your car to prevent both rust and corrosion from developing from liquids that splash up while you drive around. The spray is formulated with zinc phosphate that provides the durable and lasting seal on your car’s frame. A single can covers an area of about 10 feet, and thanks to the included spray nozzle gives you complete control over the spray. It does take over 24 hours to fully cure, but that’s 24 hours you only need to do once; you don’t have to go back and do another coat after the first 24 cure.


  • The Eastwood rust coating expands to fill pits, gaps, and crevices in the frame to eliminate and seal against rust
  • Spray nozzle makes it easier to reach up under the chassis to get better coverage of the frame and chassis
  • Phenolic resin and zinc phosphate combine to create a solid and durable coating that not only seals, but repairs metals.


  • You have to be careful with the spray because it has a tendency to drip and leak out of area beyond where you are targeting the spray

POR-15 Chassis Black Top Coat

Whether starting from scratch or trying to rescue your car from the grips of on setting rust, POR-15 is a first stop choice. With a properly prepared surface, Top Coat won’t absorb moisture, crack, or peel. This is an awesome feature that means once applied correctly you won’t have to keep repeating the work. >>> Check price on Amazon

POR-15’s Top Coat is more than just rust prevention thanks to the formula design that also resists scratches and abrasion. Nothing is more frustrating than spending a ton of time spraying and protecting your car just to have some chunk of rock jump and damage your hard work. The extra protection is a nice backup against all the things that try to attack your car every day.

This coating comes in three color varieties chassis black, glossy black, and clear that are each resistant to sunlight exposure, and reduces fading and sun damage. Again, this is a nice back up to make sure that your cars’ metal surfaces can stand up to the elements.


  • The spray is even and consistent and helps to achieve a professional appearance
  • The moisture resistance and strength against cracking is great for the under chassis, especially in wet climates
  • The Top Coat can be applied to multiple surfaces, making it versatile and strong
  • The can covers a surprisingly large area


  • The color of the black is lighter than I would have liked, and the gloss isn’t as bright as I would have imagined

Transtar Amber Rustproofing

The problem with some coatings is that when you apply them you often are changing the color, but Transtar’s Amber rustproofing spray is designed to match OEM appearance. Not only will it match color, but Transtar will also restore the rust and corrosion protection that your car had when it was new. >>> Check price on Amazon

The tacky texture is both a good and bad of this spray. When sprayed, it grabs hold of the metal and hangs on for a lasting coat. The downside is that it isn’t designed for application on exposed metals. This is strictly under the car spray. The texture remains tacky after application, so while you get a good seal, you can’t have n in areas that will be touched or come in contact with other materials.


  • The spray expands to fill gaps, crevices, and pits caused from rust and corrosion
  • When fully cured, the seal is waterproof and provides a high level of protection for the undercarriage and frame of a vehicle chassis
  • Matches OEM appearance and performance


  • Even after drying, the texture is tacky making it only useful for non-contact areas

Krylon ‘Rust Tough’ Rust Preventive Enamel

The Krylon preventive enamel is great thanks to its rapid drying that only takes about two hours total. You can handle is sooner, but Krylon recommends waiting at least two hours. Similar sprays can take up to 48 hours to dry, so two hours is a reasonable amount of waiting time. >>> Check price on Amazon

Applying the Krylon is easy thanks to the lack of primer needed to properly coat your metal surfaces. Once applied and dried the Rust Tough gives your car a long lasting shield against rust and corrosion. The spray comes in a variety of colors that each provide superior resistance to rust, as well as resistance to fading caused by sun exposure.

The sun isn’t the only hazard on the road, so Krylon has formulated Rust Tough to stand up and perform even in the harshest environments. Places with heavy rains, snow, and ice tear into metal, but Krylon is up to the challenge.


  • Dries quickly, and when dry has flat and even coverage
  • Works very well to protect in extreme outdoor environments
  • Great color once dried. With a little polishing, the Krylon has a surprisingly good shine.
  • The even spray from the can makes the finished product look almost professional, and gives new life to old cars.


  • The can comes in a smaller size than similar products, so you don’t get as much coverage per can.

Selecting and using a rustproof spray

According to the ideal time to apply rustproofing is immediately at the time of purchase of a brand new vehicle. However, most of us have cars that have been on the road for a while and need to be rescued from invading rust. So, selecting the best rust prevention spray for cars becomes more vital the longer your car has been on the road.

What makes a good rust protection spray

The best rust protection sprays are solvent-free and act more like a lubricant or wax that coats the metal instead of cleaning or stripping the metal. (>>> Check long lasting waxes guide )The sprays on our list all have the quality of a fine coat the latches onto the metals of your car to resurface and seal the metals to create a long-lasting shield against rust and corrosion.

The other quality you want to look for in a rust spray is the ability to not only protect but to add some restoration to area of your chassis that may have already been damaged from existing rust. You always need to be sure to prep the vehicle before spraying and getting a spray that doesn’t just cover the rust is your best option for lasting protection. Sprays that expand to fill gaps and pitting caused by existing rust will go a long way to make sure the rust doesn’t develop into holes or breakage.

Using rust protection spray

The key to successfully applying rust protection is to properly prepping the frame and chassis before you even start to spray. Prepping is simple as long as you take the time to do the job thoroughly. By rushing through the process will cause the coating to wear away faster.

Step one – Clean and degrease all metal surfaces around where you will be spraying. Using a degreaser, microfiber towels, and sandpaper you can take all the metal down to a flat and smooth and flat surface. Make sure to remove all the grease, and any existing loose rust.

Once you have ensured that all your surfaces are completely grease, dirt, and debris free you can begin spraying. The sprays on our list don’t require a primer, but that is not true of all sprays. If you go with another option, make sure you apply primer before moving on to spraying.

When applying be liberal and spray more than you think you need. Many sprays will work to penetrate into the gaps and seams, and that extra spray will make sure that you don’t miss any areas that need protection and coating.

The cover-up

You don’t spend a lot of time underneath your car, so you don’t see all the damage that driving around can do to your frame and chassis. Rust can start faster than you think, so applying rust prevention spray will go a long way to keep your car’s body strong and healthy.