Challenge

Underbody Coating

TTivin C Reji23 Jul 2022

UNDER-BODY COATING

Underbody coating is usually a dense cladding (often based on rubber) applied uniformly to the undercarriage of the automobile. It is normally sprayed or painted on when the car is just out of the dealership and is clean. But even if you are getting the undercoating applied after a couple of years, it’s fine too. This is because it can prevent further damage to the undercarriag. It is a sprayable coating, which protects the under surface of the vehicle from corrosion.

Underbody coating provides long term protection from corrosion to car's underbody. It also protects parts like internal body panels, frame rails and other inner cavities that are not physically accessible but are prone to corrosion.

Protecting the underbelly of the car should be our top priority. Especially during monsoon when heavy precipitation causes the roads to become mini-rivers and our cars are left stranded there. This makes them prone to heavy corrosion in the underbody region.

It protects the underbody substrates from:

Environmental conditions
Impacts
Dampens sound and vibration
Insulates against cold and heat
Protects against Corrosion
Seals off seams
Hides welds, repairs & bodywork with spray

Types of Undercoating

Rubberized Undercoating

Rubberized 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 Undercoating 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 canister 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.

Process-

When it comes to updating your vehicle or using any sort of coating, remove the rust completely first and then proceed. Rust removal is easily achieved by sandblasting or sanding, depending on the area and the extent of the rust.
Once you've removed the rust and prepped your undercarriage for coating, give it a quick rinse and let it dry to ensure you aren't further trapping any contaminants on your vehicle's underbelly. Using a degreaser to clean the metal first is also recommended.
Most undercoating is generally applied with a spray gun. A disposable spray gun will work best; once the undercoating hardens, it becomes very difficult to clean the gun even with a lot of thinner. A Schutz disposable spray gun is the best option.
No matter what type of vehicle undercoating you've selected, two coats will provide the optimum protection. Allow ample dry time between coats.
Let the undercoating cure completely (usually overnight) before driving your vehicle on the road.

Advantages

Minimizes Sound: It minimizes the sound from underneath the car resulting a noiseless, smooth driving experience.
Heat Insulation: It insulates the interior of the car from extreme temperatures from beneath the vehicle providing a comfortable cabin experience.
Anti-chipping property: If any stone hits the coating it does not get chipped away hence protects the underbody from exposure to water.

Disadvantages

Apllying underbody coating will not have any effect to the already corroded part.
Undercoating is costly.
Since the corrosion itself starts after few year, underbody coating is not preferable to ower who change their car after few year.