Underbody 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 undercarriage.
• The main purpose of undercoating is to check rust especially in the body components like frame rails along with other exposed metal parts. Underbody coating can also reduce wear and tear.
• 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.

There are many types of undercating that are as follows

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 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.

Polyurethane Undercoating

• The other option for undercoating your vehicle is to use a Polyurathene 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.

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.

Advantages of Undercoating

The obvious pros of undercoating are the protection it provides to the carriage of your vehicle. If an area where salt and sand are used on the roadways in cold weather, these materials can be corrosive to your vehicle. Undercoating gives you an extra layer of protection against rust and corrosion, protecting your car. Undercoating will eventually wear out, but you can get years of protection from it. Even vehicles in warmer climates gain protection as debris is repelled and kept away from eating at the vehicle.

Disadvantages of Undercoating

Undercoating will work best on new vehicles that have not been exposed to road conditions. A used vehicle may already have residue on the bottom of the car or even have spots of rust and corrosion. Undercoating will not help you if corrosion already exists and the corrosion needs to be removed first before it can be applied, which can be expensive for you.