UNDERBODY COATING

INTRODUCTION: Under body is part of BIW consisting of assembly made up of the front compartment, the centre floor and the rear. These compartments are held together by spot welds. The overlapping, spot-welded metal sheets must be sealed in such a way that no humidity can penetrate between the metal sheets and water in the vehicle interior, which may lead to corrosion there. The under body protection also serves as protection from corrosion, mostly for areas exposed to a high strain because of stone chips. It is applied partially two-dimensionally, for instance, in wheel arches and in the rocker panel area. Since it is one of the region we fail to inspect frequently, it is prone to corrosion there by reducing span of vehicle drastically. To overcome such scenarios it is essential to prevent these damages by a method called under body coating.

UNDERBODY COATING (UBC): Under body coating is sort of a additional layer made on to the cars under body either manually or through robots in order to withstand corrosion and damages caused. Source of damage could include common factors like potholes, muddy water & debris on the road surface majorly. Sometimes environmental factors like harsh heat radiation from road surface during summer, rich salt content in air commonly observed in coastal areas etc. could also be reasons.

BENEFITS OF UNDERBODY COATING:

• RUST PREVENTION : Brand new cars are provided with thick paint and sealants which could serve the purpose. But adding a layer of under body coating offers an added protection by stopping any contact of metal with environment to avoid corrosion.
• SOUND INSULATION : Coating with sealants also provides sound dampening effect. Unwanted noises from tyres, airflow & road noise can be dampened effectively by using coating of appropriate thickness. This is because of the sound absorbing nature of the paint used for coating. e.g. PVC coating.
• EASY MAINTENANCE : Since the under body is difficult to access without proper tool, it is hard to inspect and service frequently. However it is this region which is prone to more damages. Hence it is essential to have proper under body coating done for easy maintenance.PVC coating for about 120microns.

DOWNSIDES OF COATING.

• Increases the weight of under body as the number of layers coated is increased.
• Though it offers protection , it is expensive as well.
• Sometimes coating if not applied properly could affect relative motions between moving components such as U JOINTS, CV JOINTS, SUSPENSION JOINTS etc.

Some of the commonly used PVC (Polyvinyl Chloride) & urethane.