Underbody Coating

UNDER-BODY COATING

Introduction

Underbody coating is the process of depositing a protective layer under the body of a vehicle, to protect it from corrosion due to environmental factors or bad road conditions. It also protects from its body parts like internal body panels, frame rails and other inner cavities that are not physically accessible but are prone to corrosion. Undercoating can be applied as a liquid, typically sprayed or brushed on, and then allowed to dry. It helps to protect the axle, engine, brake system, transmission, exhaust and fuel systems, suspension parts, gas tank, and floorboards.

Corrosion is a natural process that converts a refined metal into a more chemically stable oxide. It is the gradual destruction of materials (usually metal) by chemical or electrochemical reactions with their environment. In the environment, water, mud or any less stable chemical substance can get react with the metal and corrode it easily.

So, the underbody of any vehicle consists of several metal parts which are open to the atmospheric environment and thus can be corroded easily if underbody coating is not provided. Thus a layer of underbody spray is sprayed and the thickness of which depends upon the guidelines of the manufacturer of the vehicle. Generally, it varies from some micrometres to a few millimetres. In case, if any customer does not get an underbody coating on the vehicle then he/she should definitely get the vehicle underbody coating from the market or any body shop as soon as possible.

Underbody coating Procedure

This video beautifully explains the procedure of how to get a smooth finish in the underbody coating process.

https://youtu.be/Hx9zz_2QBRE

ADVANTAGES

• Underbody coating gives an extra layer of protection against rust and corrosion and gives extra protection to a vehicle.
• Underbody coating wears out after a few years but the owner of the vehicle can timely apply the underbody coating to prevent any wear from harmful means.
• Underbody Coating needs no high labour skills except a sprayer or hand brush if not available, anyone can easily apply but it is recommended to go to an automobile body shop for better results.
• It helps to reduce the sound coming from underneath the vehicle.
• It insulates the interior of the car from extreme temperature.
• The coating does not chip away when hit by stones or debris.

DISADVANTAGES

Undercoating will not help if corrosion already exists and the corrosion needs to be removed first before it can be applied, which can be expensive.

It must be reapplied every 3 to 5 years to keep the vehicle away from the attack of reacting substances or abrasive material and debris.

It adds weight to the vehicle, it can be in the range of 10 to 20 pounds of weight. It is very less as compared to the weight of the vehicle but considerable for small vehicles.

Types of Underbody Coating

1. RUBBERIZED UNDERBODY COATING

It is ideal for cars driven in rough terrain, as its name suggests, this undercarriage coating involves applying a rubber agent to the underbelly to protect and cushion it against dents, dust, and moisture. Rubberized vehicle underbody coating is easy to apply and offers sound-cushioning as well. 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.

Advantages:

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

Examples of rubberized undercoating include: 3M 3584 Professional Grade Rubberized Undercoating Rust-Oleum Black Rubberized Undercoating, 3M Body Schutz Rubberized Coating Black, SEM 40523 Low Voc Rubberised Undercoating Aerosol.

2. POLYURETHANE UNDERCOATING

It uses a polyurethane-based sealant that comes in canisters ready to be loaded into a spray gun and sprayed to guard the undercarriage of your vehicle.

The polyurethane used in this product is a high-quality and durable material that is perfect for any weather condition. It is ideal for standard vehicles.

Advantages:

• It has a long lifespan and is resistant to wear and tear.
• It is easily and quickly applicable.
• It trickles into cracks and rusty spots, already present on the underbelly of the car, and fills them accordingly, hence protecting the underlying metal.
• It is quick and simple to remove because it can sand easily.
• It dislodges salt, moisture, and oozing around rusty areas to bond with and protect the unoxidised metal.

Example of Polyutherane undercoat: Adam’s SiO2 Infused Invisible Undercarriage Dressing Spray for car detailing.

Disadvantages:

• For better adherence, it needs undercarriage preparation before application.
• It requires time-consuming etching with primer to bare metals.

3. WAX OR PARAFFIN-BASED UNDERCOATINGS

It is the preferred undercarriage coating for cars often driven on highways or normal roads. Sometimes it is referred to as wax-based undercoating, it provides sufficient guard for cars in fairly moist regions. Wax-based undercoating never truly hardens. 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.

Advantages:

• Readily flows into seams to guarantee any exposed and prone surfaces are protected.
• It is the most inexpensive undercoating option one can buy.
• Conveniently available in spray guy canisters or aerosol cans.

Example of a Wax/ Paraffin Undercoat: Fluid Film 1, a rust inhibitor, anti-corrosion, and anti-rust undercoat.

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.

4. 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.

It reportedly has the most damage-resistant properties. Although asphalt-based undercoating is ideal for trucks, military, and all-terrain vehicles, it will also help protect your car, truck, motorcycle, and heavy machinery from the elements.

It last long and is best for endurance vehicles that have to undergo heavy road use.

When it comes to large trucks, heavy machinery, military, and all-terrain vehicles, asphalt-based undercoating provides added durability against rocks, chips, and moisture. It’s usually available from professional service shops.

Advantages:

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

Examples of asphalt-based undercoats are Rust Bullet, an automotive inhibitor paint for rust preventive and protective coating. As well as Skyco-Ospho protective coating.

Disadvantages:

• It takes time to harden and so requires more cure time than the other three types.
• Unlike the other three, it is also, not paintable as such, not very aesthetically suitable for standard vehicles.
• For best use, use only for the undercarriages of utility vehicles and trucks.
• The only type of undercoating with a limited warranty.

5. WATER-BASED UNDERCOATING

Water-based undercoating is a protective layer that helps your car stay protected from harsh weather conditions. It is made from an advanced polymer that is non-toxic and environmentally friendly.

The product can be applied to any surface, including metal, plastic, rubber, and glass. It will keep your car protected from rust, salt, and moisture. This undercoating provides a protective barrier that lasts for only a year-depending on where you drive your car.

When it comes to DIY (Do it Yourself) undercoating, this type is the most popular. Coming in an aerosol can, it can be purchased from most automotive shops. This product is easy to apply and can be done in a single day.

Advantages:

• Thin-set, it takes a short time to dry.
• Can be done at home.

Examples of Water-based undercoats are Total Coat Automotive Sprayable Undercoating, Corroseal Water-Based Rust Converter Metal Primer, CRC SP-300 Corrosion Inhibitor, and the Evapo-Rust-Block Water-Based Rust Inhibitor.

Disadvantages:

• It requires frequent repetition as it’s not very durable
• It cannot repel ice and water like petroleum-based undercoating

6. PETROLEUM-BASED UNDERCOATING

Petroleum-based undercoating is a heavy, viscous oil-based liquid product that provides an effective barrier against moisture and corrosion.

The liquid dries and hardens to provide tough, durable, and long-lasting protection against moisture and corrosion. This product is typically applied to the undercarriage of automobiles, trucks, and other vehicles.

Petroleum-based undercoating can be purchased from your professional vehicle servicing shops.

Advantages:

• Has greater deflective abilities for road salts and grime.
• Repels ice and water because of its petroleum base.

Examples of Petroleum-Based undercoating are CRC Heavy Duty Corrosion Inhibitor and the Fluid Film Rust Inhibitor for rust prevention and anti-corrosion.

Disadvantages:

• Requires annual replacement.