What is Car Undercoating?

No matter the climate, the underbelly of every vehicle needs proper care and protection. Undercoating helps protect your vehicle against rust and corrosion.

Seals on the underbelly parts have gotten a lot tighter and more effective at keeping out dust and moisture, but there are other factors to consider. Poor roads, rocks getting thrown from the tires and denting the metal, and corrosion from road salt in the winter all play a huge part in the damage or decay of a vehicle's underbelly. Used vehicles especially will need a little underbelly protection -- while it's already been exposed to contaminants and rust, applying undercoating will prevent further damage.

The Difference Between Rust Protection and Undercoating

Undercoating and rust protection often go hand-in-hand, but they are actually two different things. Rust protection generally goes inside your vehicle, while undercoating is used for protection outside of the vehicle, and there are a variety of coatings available. Depending on the level of damage and how much protection you want for your vehicle will determine which type of automotive undercoating you choose.

Different Types of Vehicle Undercoating

Having undercoating professionally applied to your vehicle can be expensive, but fortunately, if your budget is tight, you can do it yourself for a fraction of the price. Here are some of the various types of undercoating available.

Rubberized Undercoating

Rubberized vehicle undercoating is easy to apply and offers sound-cushioning as well as protection from dust, moisture, and dings or dents.

In addition to your undercarriage, rubberized undercoating is also safe to use on wheel wells and quarter panels, and dries to a soft rubbery finish that prevents further rust, damage, or moisture seeps. The coating can be painted over and, if necessary for bodywork, can be easily removed with an undercoating removal spray.

Overall, rubberized coating is generally the best option for protecting your vehicle's undercarriage, as it provides the simplest and best protective measures against rust and moisture.

Polyurethane Undercoating

The other option for undercoating your vehicle is to use a polyurethane-based sealant. This type of vehicle undercoating is a little bit quicker and easier to apply.

Oftentimes, polyurethane undercoating will come in canisters ready to preload into an application gun. This type of sealant works by seeping into all cracks and seams, displacing salt and moisture and oozing around rusty areas to bond with and protect unoxidized metal. It also sands quickly in case you'll need to perform bodywork and can be painted over.

On the flipside, this type of car undercoating generally requires a little bit more surface prep work before applying -- sanding and applying an etching primer to bare metals before using are generally recommended.

Wax or Paraffin-Based Undercoatings

A paraffin-based undercoating will be the cheapest and quickest option available with which to protect the undercarriage of your vehicle. However, keep in mind that it will wear off quicker than other types of undercoating and will need to be stripped and reapplied at least once every year.

Wax-based undercoatings never truly harden. During application, they drip or flow into seams and cracks to provide protective properties. They are usually available in a spray gun canister or in an aerosol can and offer at least a base protection in moderately humid climates.

Asphalt-Based Undercoating

For standard vehicles, any of the aforementioned types of undercoating will provide sufficient protection. For large trucks and heavy machinery, asphalt-based undercoating provides a bit of extra durability against rocks, chips, and moisture.

Asphalt-based undercoating generally contains a little bit of rubberized material that sets up firmly and also helps soften noise. Generally sold in five gallon containers, this type of undercoating also needs more cure time than the other three, and is NOT paintable, making it best to use only for undercarriages.

Vehicle Undercoating Pros and Cons

Pros of Vehicle Undercoating

It’s hard to make someone understand what benefits undercoating brings to vehicles. These are the most common advantages that you will get after undercoating your vehicle.

1. Provides an Extra Layer of Protection

In most cases, new cars, SUV’s and trucks come with good protection underneath. But, if you are living in cold climates or coastal areas, having a coated underpart is a great advantage.

It provides your car with an extra layer of protection from rust and corrosion. While driving your car, road debris will come into contact with the undercoating instead of underneath metal components.

Before the coating wears out, you can enjoy years of protection against early corrosion. Not only underneath but also the trailer of your car can be coated the same way using trailer paint.

2. Extends the Lifetime of Your Vehicle

If the undercoating is applied properly, it can extend the lifetime of your vehicle for a significant amount of time.

Vehicle undercoating gives your car rust prevention power and makes your ride safe and functional. When you don’t apply it to your vehicle, then quick rust is the outcome, which will lead to corrosion eventually.

Meanwhile, corrosion affects the integrity of the metal parts of your vehicle, causing mechanical breakdown sooner than expected. Most probably, you wouldn’t like to see your car having such an end this early. So, undercoating would be a smart investment here.

3. Reduces Internal Noise

No one likes to have a noisy ride on their vehicles. Sometimes roads with heavy traffic cause unbearable noise pollution outside. I’m sure that you wouldn’t like to have a noisy interior as well.

Once your car is undercoated, it can reduce the interior noise inside of your vehicle and comparatively provide you with a more peaceful ride.

Many car owners reported that once they have done the undercoating, the interior noise was much less than as it was before.

4. Self-Applied Facility

It is always preferable to go for professional touch for any kind of technical maintenance. But if your budget is tight, you need not worry about it much. With your basic car maintenance skills, you can do the job for yourself.

When you go for professional help to undercoat your vehicle, it might cost you around 1500$. On the contrary, you can cover up the whole within 100$-150$ if you do the job for yourself.

This self-applied facility doesn’t come with smooth finishing like a professional one, but it surely worth the money.

5. Comes with Several Undercoating Methods

When you go for undercoating your vehicle you might come across several methods that are applied for this job. Among them, the electronic method, dripless oil spray and drip oil methods are well known. If you consider the cost then the last one is mostly applied by professionals.

You can also check out the coating paint options whether you want to go for single stage paint or double stage paint. If you are not too much concerned with the look and single stage paint is for you, though it’s old-fashioned but classic. Meanwhile, 2 stage paint gives you the proper color along with a more durable coating.

Cons of Vehicle Undercoating

Despite having some great advantages, undercoating comes with some drawbacks that don’t help that many vehicles of certain conditions.

1. Less Effective If Corrosion Already Exists

Once there is rust underneath, vehicle undercoating won’t give you many effective results. Though the coating will be covering the damage that already took place, the rust inside will continue its job to lead to corrosion.

Undercoating slows down the process, but you must remove the rust first before coating.

2. Works Well on New Vehicles

If your car is already old enough or you bought a used one, then undercoating wouldn’t be a good choice. As coating the underneath of a used or old car requires the removal of all the residue, it will cost you more which is definitely not the best idea.

So, it’s better to apply coating on new cars as they offer premium protection.

For someone who changes his vehicle every 3 to 5 years, then vehicle undercoating is not a good use of your bucks. Because most new cars offer almost 5 years of default underneath protection that you can rely on.

3. Not Impervious to Damage

An undercoating doesn’t always mean protection for a fixed amount of time. Based on your road trips and the things you have to drive against, the lifespan of your coating can be minimal.

If you are bound to drive on dirty areas, gravel roads, it can reduce the quality of this protective layer earlier than expected.

4. Need to Reapply Every 3 to 5 Years

For ongoing protection, you need to make sure you are ready to invest in undercoating your vehicle every 3 to 5 years. Most users can ride their vehicles for 5 years without worrying much once the underpart is coated.

But if you happen to live in coastal areas then you might need to do it every 3 years for best results.