Underbody Coating

UNDER-BODY COATING:

Undercoating is a thick resilient coating applied to the underbody or chassis of an automobile to protect against impact damage from small stones, which would rapidly chip ordinary paint, allowing rusting to begin.

Undercoating is usually a black, thick liquid that is sprayed on the underside or undercarriage of the car and is used to protect the metal from rust and corrosion.

There are five steps involved in the undercoating process

• Pre-treatment.
• ED (Electro deposition).
• Rust proof materials
• Primer
• Top-Coat

PRE-TREATMENT:

The pre-treatment is the process of cleaning the unwanted oil remains in the stamping process and removing the unwanted residues while in the welding process.

In this step the BIW (Body in White) is allowed take a three primary liquid dipping process such as degreasing, conditioning, phosphating. The degreasing solution is composed of alkaline salts and surfactants and can include caustic soda, tri sodium phosphate, and sodium carbonate. The surfactants are types of detergents for emulsifying oils and lubricants on the BIW.

ED (ELECTRO DEPOSITION):

This is a process where water-based paint consisting of Pigment, Resin and Solvent is electroplated or coated on either ferrous or non-ferrous surface. This is usually found in automobile body parts as a prime coat before spray painting. This ED coating provides rust and corrosion protection to the undercarriage of the car.

RUST-PROOF MATERIALS (PVC):

This is a type of sealer which acts as layer on the under body of the car to provide safety by avoiding the chipping of stones from the tyre and also minimize the sound from the underneath of the car. This process helps in eliminating the water leaks as it seems sealed using PVC (Poly vinyl chloride) and urethane. This coating is applied to the exterior and interiors of the car bod.

PRIMER:

This step is to provide the additional adhesion of the topcoat to the underbody. Which helps in providing chipping protection and enhance the appearance of the paint and also be environmentally compatible with emission regulations.

TOP-COAT:

This step is the final process of the underbody coating which consist of double layer painting like basecoat and a clearcoat of the underbody. In basecoat it contains the primary colouring pigments to the underbody and the second layer is clear coat, and it provides a protective coating against environmental effects, corrosion, and UV light degradation promotes unmatched colour retention and provides a smooth unblemished even finish.

The different types of under body coating are:

1. Wax or Paraffin-based Undercoating:

The Wax coating which is preferred for the undercarriage coating of the cars where the car often driven in the highways and also in the normal road condition, which often provide a sufficient guard for the car in fairly moist region

Advantages:

• Readily flows into seams to guarantee any exposed and prone surfaces are protected
• The most inexpensive undercoating option
• Conveniently available in spray canisters or aerosol cans.

Disadvantages:

• Wears off quicker in comparison to other types
• Unlike the rubberized type, it does not really dry
• Needs to be stripped and reapplied at least once a year as soon as signs of wear and tear start to show

2. Rubberized Undercoating:

The rubberised undercoating is to be preferred for the acting as a cushion in the undercarriage of the cars which protects the undercarriage from dents, dusts and moisture. Whether the car is driven in the rough terrains. It can also be applied around wheel wells and quarter panels.

Advantages:

• Easy to apply
• Quickly applied with no fuss
• Undercoat can be painted for a neat finish
• Provides satisfactory protection
• Truly dries to a soft rubbery finish that prevents further rust, damage, or moisture seepage

3. Polyurethane Undercoating:

This type of under coating is preferred for any weather condition and also it is ideal for standard vehicles. The polyurethane undercoating is a high-quality and high durable material. Which is available in canisters that are to be readily available to load in the spray guns for guard of the undercarriage of the cars

Advantages:

• It has a long lifespan and is resistant to wear and tear
• Easily and quickly applicable
• Quick and simple to remove, as it stands easily
• Can be painted over

Disadvantages:

• For better adherence, needs undercarriage preparation before application
• Requires time-consuming etching with primer to bare metals

4. Asphalt-Based Undercoating:

This is a type of undercoating which generally contains some rubberized materials which sets up firmly and helps soften the noise from the engine. As it is reported that it has most damage resistant properties, and it is majorly suggested for heavy machinery like truck, military and all-terrain vehicles. It last long and is best for endurance vehicles that have to undergo heavy road use.

Advantages:

• Formulated to protect from dirt, rust, and corrosion, it normally has a self-life of up to two years. Sold in five-gallon containers
• Provides extra durability as it is the strongest and thickest undercoating available.

Disadvantages:

• It takes time to harden and so requires more cure time than the other three types
• For best used only for the undercarriages of utility vehicles and trucks
• The only type of undercoating with a limited warranty