best rust prevention products

5 Best Rustproofing Paints 2018

Rustproofing is essential too ensure your car is protected during the winter season. A car could look rust free from the outside but underneath the cars condition can be a complete different story.

The best rust prevention for cars is the POR-15 45404 rustproofing paint, which provides a strong heavy duty protection against rust getting through.

Newer cars are less prone to rusting due to their age and technological advances in paints with galvanized bodywork providing maximum rust prevention. However, overtime rust will appear on any car that is used on salty roads.

Best Rustproofing Sprays

Rust Prevention SprayTypeChoice Of Colors
POR-15 45404PaintNo
Hammerite WaxoylSprayNo
Rust-Oleum 7776830AerosolYes
Krylon K09206007AerosolYes
Transtar 4423AerosolNo

Common places for cars to rust are front wings, rear arches, front valance, around the headlights, sills, floorpans, tailgate/boot lid, sub frame, jacking points and more. The best rustproofing paint will ensure your car will last another 20 years without any rust build up.

Before applying any rustproofing paints or sprays, rust must be removed prior. The best method of removing rust from the underneath of the car is by using a wire brush attachment on a drill. This will remove all the loose rust, which means you can begin to paint over it with rust preventive spray paint.

It is not a particular nice task to carry out on your car but its one of the most important and worthwhile things you can do to it. Below is a list of the best rust prevention sprays and paints that prevent rust forming again.

POR-15 45404 Rust Prevention Paint


As it says on the tin, the POR 15 formula is one of the strongest rustproofing paints. There is no spraying or heating up this product, it is as simple as dipping the paint brush into the pot and applying to the work surface.

POR stands for Paint Over Rust and its exactly what you need to do to prevent rust. It is not cheap but it is the best rustproofing product on the market that neutralizes and eliminates rust. It creates an air tight seal rust free barrier that means no more rust can get through.

Along with the POR-15 Rustproofing paint, you will want to ensure you have some cheap bristle brushes because they will be unusable after application. The POR-15 is near enough impossible to remove once hardened, which is good for your car but not for brushes and of course clothes.

The POR-15 provides heavy duty rust protection where one pot has enough paint for to complete one full car. If you are using small amount, be sure not to let any moisture into the pot because the top layer on the paint will start to harden.

Check it Out

Waxoyl Rustproofing Spray


Waxoyl is a rustproofing product that I use on the majority of my cars. You are able to choose from a black or clear coat spray that you can spray all over the undercarriage of your car. I recommend getting 5 liters as there is nothing worse than running out half way through the job. I usually use 90% of a 5 liter can per car.

Be warned that using Waxoyl is a messy job and you should wear old clothes and face masks. In order to apply the product properly, put the Waxoyl can into a bucket full of boiling hot water. This has the effect of heating the product so its thinner, therefore it is easier to spray from a nozzle and provides more coverage.

Waxoyl forms a “skin” like wax coating on the metal work that protects the metal from all road dirt. I have used this a countless number of times on my Mercedes’s and haven’t had any problems with rust on areas that have been treated by this product.

There are very mixed reviews on the internet regarding Waxoyl. The majority of people are confusing the product as a rust killing product as opposed to a rust barrier. Rust must be removed prior to applying this rustproofing product for full effect.

Other bad comments are people complaining about the Waxoyl becoming hard/blocked and this is because they probably didn’t read the instructions to heat the product up before use.

Through correct application of this product, it provides excellent rustproofing capabilities and I highly recommend if you don’t mind getting messy. The benefits of rustproofing a cars underneath is endless and Waxoyl can reach all areas that using a paint brush will not be able to.

Check it Out

Rust-Oleum Stops Rust Spray Paint


The Rust-Oleum is one of the most popular aerosol type of rust prevention spray due to its low cost and superior coverage from the spray can. It also offer over 30 different colors to choose from in order to match your paintwork.

Rust Oleum provides a weather and corrosion resistant coating from its oil based formula, which is dry to touch within just 2 to 4 hours. It will cover up to 15 square feet but due to the low cost, its worth buying a few cans.

For those on a budget and wanting a simple solution that is quick, the Rust Oleum is the best rust prevention spray for the money. POR-15 and Waxoyl are both a long lasting and professional product that does require time to apply it to your vehicle, but not this rust prevention spray.

Check it Out

Krylon RTA9206 Rust Preventive Enamel


Krylon RTA9206 rust protection is a simple to use aerosol that dries within 30 minutes. Similar to the Transtar 4423, the Krylon RTA9206 does not need any preparation in terms of heating up and its as simple as spraying onto the metal you are treating.

One of the main reason the RTA9206 formula is rated is because you can choose the color of the paint. From yellow to red, there are plenty of colors to choose from which is ideal for cars such as 4×4 and SUV’s where the underneath of the car is visible.

Check it Out

Transtar 4423 Amber Rustproofing


The Amber Rustproofing Transtar product comes in a handy aerosol which you can spray directly onto car panels. The product is ideal for covering the hard to reach areas in the undercarriage of the car. Due to the sticky texture once dried, avoid spraying the product on accessible surfaces such as the interior.

Unlike other rust proofing products, the 4423 Transtar does not need to be heated and can be as easy to spray as a deodorant bottle. The thin spray takes a while to dry but this results in a hard protective wax to prevent rust.

Check it Out

What is the Best Rustproofing Product for Cars?

To fully protect cars that have had rust removed and are now ready for the road, I prefer using a mixture of products. As mentioned, I have used Waxoyl on several occasions and when applied properly, the spray nozzle provides large coverage to hard to access areas.

However before spraying the Waxoyl, I use POR-15 on exposed metal, which require heavy duty rustproofing. Circled in red are the areas I applied the POR-15 before spraying waxoyl as per the top photo.

rustproofing POR-15

This method of rust prevention has deemed very successful over the years with various cars. Before applying any products, ensure that the surface has been cleaned throughout and then dried. Its vital that no dirt or moisture is left as this will become trapped and cause rust itself.

Applying rust prevention paint to any car does not actually take that long. I usually apply the mixture of Waxoyl and POR-15 every time I replace the brake pads and discs.

What Causes a Car to Rust?

In general, car rust is caused by metal being exposed to iron, oxygen or water where the reaction oxidizes the metal. This process can be caused by the following:

  • Mud building up in inaccessible areas such as a wheel arch lips
  • Stone chips or minor damage
  • Driving regularly on salty roads during winter
  • Living near the sea (high moisture and salt)
  • Blocked car drain holes

rust on wings from road salt

How to Prevent a Car Rusting?

The obvious answer is by not driving it at all but that is no good. Road salt is one of the main reasons for car rust and its mostly during the winter season. For those with only one vehicle to drive, driving in the winter season with salt spread across the road is inevitable.

For those winter months, its vital that you thoroughly wash your car and paying special attention to the undercarriage and washing all four arches excessively. With the build up of salty and dirty roads, be sure to check that the drain holes are all clear and water can run through.

Stone chips and damage from driving is also hard to avoid in everyday driving. Using the correct protective wax for your paintwork will provide an excellent source for prevent stone chips and repelling road dirt from your cars bodywork.

However, the best tactic for avoiding rust on your car is by applying rustproofing products as reviewed. This prevents the car metal getting in contact with any dirt or water that will cause the rust process.

Before applying any of the rust proofing products, its vital that the car is as clean as possible with all mud and salt removed. If this process is not carried out, you are trapping the contaminants in between the cars metal and rustproofing product.

How Much Rust Is Too Much On a Car

Rust on the outside of the car such as front wings or bottom door edges are usually nothing to worry about. The places that you should worry around is structural car rust such as the sills, frame, chassis and floor pans.

The most common car rust I see is located on front wings. For the average car, front wings would cost around $200 each and it would cost $150 per panel to paint. You can then use this cost of repair to get a cheaper price on the car, with the peace of mind they would be rust free for years to come.

On the flip side, bad car rust can make a car worthless. Rust to the chassis or sub frame would be bad rust in my opinion. In the UK, rust to these areas would fail the MOT and would also fail vehicle inspection in the US.

All rust can be treated depending on how deep your wallet is. When inspecting a car for rust, check the main areas and get your head right underneath the car to check. Ensure to ask the owner what rust prevention work they have completed and whether they use the car much during the winter season.

What Are Your Thoughts?

  1. Waxoyl, although a good product is not available in the US. I have found that the best product with the most active rust prevention and easy application available here is Noxudol, available on Amazon, reasonably priced, and quite effective on all parts of the car from inner fenders and inside the rockers to undercarriage, not too messy and it does not affect rubber components like some others do. Four years later and no rust under my plow truck. Noxudol 750 for body and cavity wax and Noxudol 900 for undercarriage. Good stuff

Leave a Reply

Your email address will not be published. Required fields are marked *