Unfortunately, rust is an inevitable part of a car’s life. Although you can’t stop it completely, you can treat your vehicle to slow down rust build-up. In this guide, we’ll explain how to rustproof your vehicle from your own garage.
What Is Rustproofing?
As the name suggests, rustproofing is the process of protecting your car from rust. It’s sometimes used interchangeably with undercoating, but these two processes are not exactly the same.
Rustproofing targets specific areas of a vehicle (both inner and outer parts of the structure) where rust is most common. Undercoating is the process of spraying a wax or rubber-based composite on the entire underside of a vehicle. It’s technically a form of rustproofing, but is meant to protect against all elements that touch the underside of your car.
When to Rustproof
The best time of year to rustproof your car is in the spring or summer, when the weather outside is warm and the roads are dry. If you miss this window, it’s still a good idea to rustproof your vehicle before winter, because the road salt will make your car much more prone to corrosion. Go through this process once a year to keep your car looking its best.
All new cars are treated for rust protection and given an undercoat. Unless you excessively expose your vehicle to corrosive environments, you shouldn’t have to rustproof it again for at least two years. If you buy a used car, you may want to rustproof it early on, depending on how old it is and how much visible rust it already has.
You can pay to have your car rust-proofed at a garage, but if you like to DIY, you can save a lot of money by adding this task to your own routine.
Preparing for Rustproofing
Step 1: Start with a Good Wash
Start your rustproofing process by giving your vehicle a good wash. You can do this at a local car wash or from home. To complete a thorough DIY wash, follow this guide. Make sure to clean the entire vehicle exterior, paying extra attention to hard-to-reach areas like the wheel wells (which not all car washes adequately reach.)
Step 2: Remove Existing Rust
To deter future rust, first remove any rust your car has already acquired. In most cases, rust can be removed/repaired, but it may require more work than you expect. Scale rust (a.k.a. rot), is much more detrimental to your vehicle than surface rust, because it can weaken the body of the car over time.
For surface rust, you’ll need tools like sandpaper, primer, paint, and clearcoat. Once you’ve removed the rust with sandpaper, you may have chipped away some paint. That’s why you should keep some nearby to patch up any scratches. If you apply fresh paint, be sure to let it fully dry and cure before moving on to the next step.
For scale rust, you’ll need a bit more elbow grease and might have to do some part replacement. A wire brush will come in handy with this kind of stubborn rust. Always work in a well-ventilated area when dealing with rust.
Step 3: Apply Rust Protector
Now you’ve got a clean surface to work with, it’s time to start rustproofing. You can use a spray gun for this, but an aerosol can is a much more affordable option.
These products may stain surfaces, including concrete and asphalt, so consider putting a tarp down before you spray. Protect areas of the vehicle that you don’t want the rust protector to hit (e.g., exhaust, brakes, drive belts) by covering them with plastic and/or tape. To give your car an undercoat you’ll need a jack and jack stands to reach underneath it.
Read all the instructions on the rust protector spray you choose. When you’re ready, apply it all over the exterior of the vehicle. Most people target the wheel wells, upper body panels, tailgates, and fenders. Using an undercoat? Spray it on the entire undercarriage.
Spray both products using smooth, even strokes.
Depending on the particular rust protector, it can take anywhere from a few minutes to several hours to fully dry. Apply two coats for a thorough layer of protection.
Pair rustproofing with these other tips to prevent rust to prolong your car’s look.
Other Tips to Help Prevent Rust
The best way to prevent rust is to wash your car frequently. Doing so will stop debris, salt, and grime from building up and causing rust. Instead of waiting for your car to be visibly dirty, wash it at least twice a month. This timeline will vary according to the conditions you drive in.
For more car maintenance tips and DIY guides, check out our blog.