Underbody Coating
Under-body coating
1. Introduction:
Underbody coating is a thick resilient chemical/ sealant which is used to protect the vehicles chassis from external environmental conditions & ensure the long life of the underneath parts as well as their safety.
Underbody coating protects the vehicles from corrosion. It also protects parts like internal body panels, frame rails and other inner parts that are not easily accessible but may get corroded if not gives required treatment.
A car’s underbody may get detroit with time due to day to day running and variety of obstacles like uneven road, stones and wear & tear.
2. Types of Under-body coating:
(A) Rubberized Underbody coating
Rubberized vehicle undercoating is easy to apply and offers sound-cushioning as well as protection from dust, moisture, and dings or dents.
In addition to your 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.
(B) Polyurethane Underbody coating
The other option for undercoating your vehicle is to use a polyurethane-based sealant. This type of vehicle undercoating is a little bit quicker and easier to apply.
Oftentimes, polyurethane undercoating will come in canisters ready to preload into an application gun. This type of sealant works by seeping into all cracks and seams, displacing salt and moisture and oozing around rusty areas to bond with and protect unoxidized metal. It also sands quickly in case you'll need to perform bodywork and can be painted over.
On the flipside, this type of car undercoating generally requires a little bit more surface prep work before applying -- sanding and applying an etching primer to bare metals before using are generally recommended.
(C) Wax or Paraffin-Based Underbody coating
A paraffin-based undercoating will be the cheapest and quickest option available with which to protect the undercarriage of your vehicle. However, keep in mind that it will wear off quicker than other types of undercoating and will need to be stripped and reapplied at least once every year.
Wax-based undercoatings never truly harden. 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.
(D) Asphalt-Based Underbody coating
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.
3. Process of Underbody Coating:
(A) Pre-treatment:
This is the first step of the Underbody coating process. It consists of cleaning the BIW surface by removing the remaining oils from the stamping process and welding residues through three primary liquid dip processes of degreasing, conditioning and 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 & lubricants on the BIW.
(B) Electrodeposition (ED):
The metal underbody and frames of automobile are coated to prevent corrosion, the structural metals are primed before applying additional coatings. The ED processes are modified as per the BIW material property. The ED coatings provides rust and corrosion protection.
(C) Rust proof materials:
Sealers/PVC, the third step is UBC (Underbody Coating) and seam sealing using PVC and urethane. The sealant is applied around and inside the doors, hood , trunk and front dash and onto the exterior and interior of metal joints and outer area of the back wheel well.
(D) Primer:
The 4th coating step is the application of primer surface or simply primer. It can be water borne, solvent-borne or a powder. These primers are used to improve adhesion between the E-coat and the top coat , provide chipping protection enhance the paint appearance.
(E) Top Coat:
The final step in the underbody coating is to apply a top coat which consists of two layers- the Base coat & clear coat. The Base coat contains the primary colouring pigment and clear coat provides a protective coating against environmental effects, corrosion and UV light degradation promotes unmatched colour retention and provides a smooth unblemished even finish.
4. Pros of Underbody coating:
(A) Heat Insulation:
It insulates the interior of the car from extreme temperatures from beneath the vehicle providing a comfortable cabin experience.
(B) Protects Against Rust & Corrosion:
The primary objective of getting underbody coating done is preventing metal components that are exposed on the bottom side of the car to damage from corrosion. You can shut out the Adverse effects of corrosion on your car by simply applying a rubberised anti-rust coating all over the belly of your car.
(C) Reduces NVH (Noise Vibrations Harshness) Levels:
Our country is filled with roads having uneven patches and potholes and while we manoeuvre our cars through such sections, the unpaved crumbs, and pebbles hit the car from underneath or get stuck in the wheel wells. The underbody coating’s consistency is so thick that the layer it creates absorbs all the unpleasant noises and vibrations and marginally improves the driving experience.
(D) Prevents Paint Chipping:
Running on the highway or while pacing through a city road, you will often encounter sharp gravel or any other unattended object hitting the belly of your car with high momentum. This scrapes and chips off the metal from down below. A thick layer of Underbody Coating definitely comes to aid and minimises the effects of such contacts on the body.
(E) Protects Vital Components:
Underneath a car is somewhere a lot of indispensable parts of a car are left exposed like the Engine, silencer, etc. One simply can’t afford to let these parts go bad due to rusting and hence in order to save yourself from a hefty repair bill, a considerably less expensive Anti-Rust Coating is a must.
5. Cons Underbody coating:
(A) High Price of Vehicle Undercoatings: But perhaps the biggest issue people have with professionally installed automotive undercoatings and rustproofing procedures, is how much they cost. Sure, the initial shock of having to cough-up a few hundred bucks so that a professional can undercoat your vehicle may be shocking, it is nothing compared to the cost of replacing an entire vehicle due to rust damage. This is precisely the reason why many people opt to take matters into their own hands, and attempt to undercoat their automobiles on their own, a topic that we will visit here shortly.
(B) Not effective if there is already corrosion: A used vehicle may already have residue on the bottom of the car or even have spots of rust and corrosion. Undercoating will not help you if corrosion already exists and the corrosion needs to be removed first before it can be applied, which can be expensive for you.
(C) Weight: A used vehicle may already have residue on the bottom of the car or even have spots of rust and corrosion. Undercoating will not help you if corrosion already exists and the corrosion needs to be removed first before it can be applied, which can be expensive for you.
(D) It needs to be re applied every 3 to 5 years for best results.
(E) A UBC can provide a hardened layer of protection against dirt and debris but the lifespan of this product is minimal. If you drive your vehicle off-road, it will reduce the integrity of the protective layer.