Underbody Coating

UNDER BODY COATING:

Underbody coating is one of the coatings which is coated on the under bodies of cars. This coating is done while BIW coating. Different layer of coating is done in this process.

Why done under body coating:

• This coating prevents the under bodies of car against corrosion & rust. This coating product from dust, moisture and other different environment condition.
• In raining condition different dirty water affected under body car.
• If we coating under the car it will prevent from this water and dusts. This coating is done while BIW coating.
• It prevents under interior parts of cars from different dusts, dirty water and heat.

Process:

Five steps of automotive coating process:

1. Pre treatment
2. Electrodeposition (ED)
3. Applying rust proof material
4. Applying primer
5. Final coating

1. Pre-treatment:

First step of car body coating is preparing BIW for coating process. In this step remove excess material from BIW. In this step forms an appropriate surface to enable bonding of next step. When BIW forming lot of lubricants applying like welding. In this step removing oils and lubricants.

2. Electrodeposition:

The second step is electrodeposition in which step applying anti correction or rust prevention layer. In this step BIW is dip into electrodeposition medium in which give slit movement or give 360-degree rotation to BIW. When we give this moment, coating is uniformly applied on BIW and bubbles are removed. It gives new properties to the BIW. Now, BIW get correction production layer.

3. Applying rust proof material:

This coating applies for elimination of water leaks, minimizing of chipping and vibration noise and anti-correction. It is called sealer. Mostly PVC and urethane are applied as sealer which is applies hood, trunk, doors, front dash, outer are of back wheel and interior and exterior metal joints.

4. Applying primer:

This coating increases adhesion between e coting and final coating. It also gives smooth surface for subsequent layer and anti-chipping properties. It can be water borne, solvent borne or powder. It also increases appearance of paint and environmentally compatible with emission regulation.

5. Final coating:

Final coating consists two layer which are base coating and clear coating. It is final coating which gives colour, gloss, appearance smoothness and water resistance to the car. In this coating we will choose colours. This final coating be on the vehicles. So, prevent UV light degradation, correction, environmental effects. And it will give unblemished even finish. Most of companies have done by automatic. Some companies have done by semi-automatic.

Types of underbody coating;

These are classified by using various types of material and cost of materials.

1. Polyurethane coating
2. Rubberized coating
3. Wax or paraffin-based coating
4. Asphalt based coating

1. Polyurethane coating:

In this type of coating polyurethane material is applied. It is quicker and easy to apply. It is applied by preloaded gun. This type of coating must require surface preparation.

2. Rubberized coating:

Rubberized materials are applied in this type. It offers sound cushioning as well as prevent from dusts, moisture and dents. It is very good safety for wheels wells and quarter panels. It also gives rubber soft finish.

3. Asphalt based coating:

This coating is mainly used for heavy vehicles such as truck, buses, vans etc. This asphalt-based coating is used to product against moisture and rock chips. In this type of coating asphalt-based material applied and little bit of rubberized materials applied which reduces noises.

4. Outside coating on top painting layer of car: Wax or paraffin-based coating:

It is differed from other coatings. Because, it is applied on the outer coating of car. Wax type of material applied in this type of coating. It is very cheapest and quickset option in the market. It gives gloss look for car and prevent from dusts. But this types not be for long time duration. Ceramic coating also available as well as this type.

Pros of under body coating:

1. Anti-chipping properties:

This coating prevents chip away while hit by stone.

2. Minimizing sound:

It minimized sound from underneath the car.

3. Heat insulation:

It insulates the lower interior parts of the car from extreme temperature and heat condition.

4. Prevent correction:

It prevents rust and other type of correction

5. Prevent internal bodies:

It gives long term production of the under body of car. It also products like frame rails, internal panels and inner cavity.

Cons of under body coating:

1. High cost:

It is good for vehicles but processing and material cost is expensive. So, this type vehicles rate is high.

2. Damage during application:

When we giving under coating. Some time it would affect shafts, joins other components.

3. Added weight:

When we adding under coating car vehicle weight would increase. So, fuel efficiency is decreased.