Undercoating VS Bedliner | What should I use to undercoat my truck?

Has anyone used a spray can to protect their vehicle’s wheel wells and fenders? The undercarriage area of the car or vehicle is the most ignorable part, and we often forget to look after it. As a motorist expert, many vehicle owners visit and ask me which spray coating goes longer, Undercoating VS Bedliner. 

I have read on the forums that many motorists have used bedliner to restore the fender, but as a result, it dries quickly and peels off. Conversely, a few have applied rubberized undercoating, which also deteriorated. I conclude that they did not prep the surfaces well, leading to the sprays’ poor adhesive bond

Because of its location, the undercarriage exposes to the roughest and toughest road areas. In this spite, it experiences the most dirt, grime, debris, and anything on the road. Protecting your vehicle’s undercarriage is essential to maintain a great look and shape. In this guide, I will explain both sprays can’s usage and functions that help you pick the best one.

Before diving into differences, let me explain their literal definitions and purposes. 


What are your thoughts on having a debris-contaminated undercarriage?

Undercoating is an innovative automobile accessory. Its primary function is to add layers of protection in the vehicle undercarriage in order to prevent it from dirt and debris. Additionally, it will extend the life and value of your vehicle.

As we all know, undercarriage comes into contact with outer substances like water, dirt, salt, and debris from the road. Without applying coats of protection, the bottom of your truck or car becomes rusty and corrodes, leading to the failure of the part. 

Since the car manufacturer did a fantastic job sealing and securing the beneath part of the vehicle, the road debris caused major damage to the exposed undercarriage. 

That is why manufacturers and dealers advise getting a professionally done undercoating when you purchase a new vehicle. Also, to maintain its life span and value, I recommend re-undercoating the part to prevent it from any harm. 

But undercoating protects the undercarriage part?

Using an undercoating beneath the vehicle protects the undercarriage from getting rust and rot. It creates a protective layer between the undercarriage and rust and keeps it from any road damage. 

An undercoat has a rust protection serum that goes inside the undercarriage and protects it from corroding and other elements. Depending on the protection you want to offer your vehicle, both one or double coating are available, and you can get it according to your needs and preferences. 

What is the most popular undercoating?

Several types of undercoating are available on the market to help you protect your undercarriage from outside elements. However, the most popular and best type is Rubberized Undercoating.  

By the name, you can get the idea that Rubberized undercoating provides a sound cushioning/padding layer of protection for the undercarriage. It can apply on fenders, wheel wells, and quarter panels. 

The method of using this coating is straightforward. It quickly dries up and turns into the rubber layer, which gives peace of mind that moisture and dirt do not get inside. It is a go-to option for most motorists because it is a breeze to use and remove. Moreover, you can paint over it. 

The other best type of undercoating is Polyurethane. This one is uncomplicated to apply since it comes in canister packages ready to put down in application guns. Moreover, Polyurethane does a fantastic job of filling cracks and dents in your undercarriage while clearing out rust and moisture. 

The only drawback of this undercoating is it needs a lot of prep work. 

Another option for your undercarriage is Asphalt-based undercoating. It is mainly used for heavily exposing the undercarriage to debris, mud, and dust. It is quite a stronger and more durable kind of undercoating. Additionally, it has the ability to sound deadening. 

Note: Asphalt-based undercoating is easy and quick to apply. However, it can wear out sooner than other types of undercoating. It is best if you want a temporary protective layer for your undercarriage. 


Bedliner is a protector applied to the vehicle that prevents it from abrasive damage. It specifically manufactures vehicles, and its function is to protect surfaces from outside elements such as dirt, debris, and moisture. 

Initially, it was made for a truck bed. Later, truck owners find it useful and helpful in protecting their vehicle’s undercarriage from damage. 

In some ways, a bedliner is more effective and efficient in protecting your undercarriage than undercoating.

Likewise, undercoating, a bedliner is easy peasy to install. It comes in a kit. When you apply a bedliner, it quickly dries and turns into a dust and mud magnet. As a result, it absorbs moisture and prevents the undercarriage from rusting. 

Bedliners have chunks of rubber material that stick to the undercarriage, offering protection from rust, debris, and deadening sound. Thanks to its design and material. 

To choose a bed liner for your undercarriage, there are various well-liked and reputable on the market. You can choose which matches better depending on your needs and preferences. For example, some offer a decent finish and are durable yet protect the undercarriage surface from outside damage. 

Note: Ensure you prep the surface before applying the bedliner. Because if you skip this part, the bedliner does not bond with the undercarriage. Also, I recommend scrapping the rust from the surface before applying the bedliner.

Undercoating VS Bedliner – The Difference

Undercoating VS Bedliner, both options are good to protect the undercarriage from the damage of rust and decay. However, both are different in their functions and specifications.

Bedliner offers a decent look

A bedliner offers a more decent finish and an attractive look to your undercarriage. A bedliner is your way to go if you are an aesthitc person. But this does not mean undercoating looks bad or terrible; it just does not look appealing. 

Undercoating is less durable

As a motorist expert, a bedliner is durable and lasts longer compared to its counterpart (undercoating). Many vehicle owners complain that undercoat cracks and peel off easily. So if you are looking for long-term protection, that bedliner is an ideal product to choose from. 

Bedliner is thick 

There is a saying the thicker the coating, the better protection it will offer you. 

Bedliner is thicker than the undercoating. The latter needs several coats to achieve the exact thickness of the bedliner.  The other positive side of a thicker coat is the sound cushioning. 

Unlike Bedliner, Undercoat stays in a sticky and gooey form

When installed wrongly, the undercoat remains in a gooey form, which reduces its durability and longevity. Unlike an undercoat, the bedliner quickly dries and turns into a hard surface.

Can bedliner be used as undercoating?

One of the greatest advantages of a bedliner is it can use as undercoating. A bedliner provides a layer of protection to your undercarriage or chassis from rust, corroding, moisture, and road dirt. I prefer to use a bedliner because it is twice thicker than undercoating and more durable.

Does undercoating actually prevent rust?

Undercoating is a spray in various forms, such as rubber and wax. It uses over the bottom parts of the vehicle, like the fender, wheel wells, and undercarriage area. It prevents rust, debris, and grime from accumulating on surfaces. Moreover, it provides a protective layer on your vehicle areas. 

Can you use Raptor liner as undercoating?

A Raptor liner is a perfect way to cover seams and marks. Also, it dampens the sound when installed over the engine compartment. Using Raptor Tough Undercoating quickly sticks with metal, aluminum, aluminum, and plastic and offers an attractive finish. 

Conclusion – What to use as undercoating?

Undercoating and Bedliners offer the great capability to stick with the vehicle’s parts. Both are best in protecting the vehicle’s bottom part by adding protective layers that protect them from rust, debris, dirt, grime, and other elements. 

To choose from them, a Bedliner is an ideal product. It has more thickness which helps to dampen the sound and protect the parts to the next level. Moreover, it offers a more aesthetic and attractive finish compared to undercoating. 

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