Underbody Coating
Underbody coating
The underbody coating that is most commonly used on cars in India and supplied by companies such as 3M is a thick, rubberized
paint that forms a 2-3 mm thick coating all along the underside of the car when sprayed on. You also get a thinner clear coat
underbody coating which is like a lacquer that coats the entire underside of the car. Some even inject rust-preventive coating
material into crevices such as the bottom of doors and door sills, to protect them from rust.
Some car manufacturers already offer some underbody coating straight out of the factory which is usually sprayed inside the wheel
arches and under the floorboard of the car.
Here are some benefits of underbody coating:
Rust Prevention
Ideally, any additional underbody coating should be applied when the car is brand new and clean. Car manufacturers use thick paints and sealants for the underbody, but adding an underbody coat, especially in coastal cities is useful. Saltwater tends to corrode cars really badly. On bad roads, flying stones and pebbles can chip off the original underbody coating and leave the metal exposed. Using an aftermarket underbody coating offers extra protection.
Sound insulation
The thicker underbody coatings used on cars also act as effective sound dampeners. They can reduce road noise and tyre noise and
make the cabin seem quieter – due to the sound absorptive nature of rubberized paints.
Easy maintenance
A uniform black underbody coating gives a car a clean look. It also makes the car easier to maintain by just hosing the underside
down. You can be confident that slush build-up won’t lead to rusting easily. Most underbody coats these days come with a five-year
warranty, which is the lifetime of such a coating.
Prolong Car’s Life
Good undercoating not only defends the underbody from corrosion but also protects the engine and transmission as well! Less rusting coupled with slower wear and tear can surely add years to the lifespan of your vehicle. There would be fewer dents, dings and scratches on the undercarriage for you to fret about.
Modern procedure for automotive coating processes:
Pre-Treatment - The excess material is removed and the surface is cleaned to make it suitable for the coating process. The dirt
and welding residue is cleaned and removed during pre-treatment. The pre-treatment also consists of 4 stages [Hot Water,
Degreaser, Surface Conditioner, Phosphate] which are done before electrode deposition processes.
Electrodeposition - The electrode deposition coat provides rust and corrosion protection. It is done over the Body in White. The
metal underbody and the frames are coated to prevent corrosion. While areas that are not coated are primed before applying
the additional coating.
Rustproof materials [Sealers/PVC] - The underbody coating has some specific advantages when compared to that of
electrode deposition. The underbody coating has noise reduction, vibration reduction, and anti chipping properties in addition
to that of underbody coating.
Primer - The primer is applied over the top body of a car to improve weather resistance, improve appearance, chipping
resistance, improve adhesion between electrodeposition coat and topcoat and reduce the volatile organic compounds that
cause atmospheric pollution.
Topcoat - The topcoat has two stages, the base coat and the clear coat. The base coat has the primary colouring pigment,
while the clearcoat provides a protective coating against environmental effects, ultraviolet light degradation, unmatched colour
retention and a smooth even finish
Types of Undercoating
- Rubberized Underbody Coating
This is generally thought of as the best underbody coating for your car. It preserves the underbody well, protecting it from scratches. Applying this to the undercarriage is not much of a hassle either.
2. Wax Based Underbody Coating
This – more or less – ephemeral undercoating will wear away in a few months’ time. On the upside, wax-based undercoating puts up a big fight against moisture. It is also the most affordable option out there.
3. Asphalt Based Automotive Undercoating
Best suited for lorries, trucks and large vehicles this provides a greater degree of protection compared to rubber-based coatings. However, asphalt-based coatings contain little amounts of rubber for sound-insulation purposes. The process of applying this coating is a bit time-consuming though.
4. Polyurethane Underbody Coating
This coating closes up splits and fractures on the underbody of the vehicle. It offers up good protection against corrosion and also bonds with the metal. Unlike in the case of asphalt-based coating, you can paint over the polyurethane coating.