Underbody Coating
What is Under-body coating?
Underbody coating 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. No matter the climate, the underbelly of every vehicle needs proper care and protection. Undercoating helps protect your vehicle against rust and corrosion.
Seals on the underbody parts have gotten a lot tighter and more effective at keeping out dust and moisture, but there are other factors to consider. Poor roads, rocks getting thrown from the tires and denting the metal, and corrosion from road salt in the winter all play a huge part in the damage or decay of a vehicle's underbody. Used vehicles especially will need a little underbody protection -- while it's already been exposed to contaminants and rust, applying undercoating will prevent further damage.

Types of under-body coating
Rubberized Undercoating
Rubberized 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.
Overall,rubberized coating is generally the best option for protecting your vehicle's undercarriage, as it provides the simplest and best protective measures against rust and moisture.
Polyurethane Undercoating
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.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,
Asphalt Based Automotive Undercoating
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.
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.
Wax or Paraffin-Based Undercoatings
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.
Pros of Undercoating
- Fights Rust
It plays an important role in keeping corrosion at bay. Underbody coating can come in handy especially if you live near the sea, where there is too much humidity, and rusting is just one of those everyday things.
You should also seriously consider undercoating if you reside in a place where it snows in winter.
- Absorbs Noise
Believe it or not, very thick undercoating can soften the noises that reach the cabin. Since the undercoating is often made up of rubber it absorbs some of the rackets. The occupants of the car could spare themselves of the road noises – at least up to a certain extend.
- Reinforcement
If your car comes with stock underbody coating, using another coating on top of it, is not going to hurt. It will offer additional reinforcement, protecting the underbody from water, road debris, gravel and small pebbles. There would also be a lesser chance for the factory coat to flake away.
- Prolong Car’s Life
Good undercoating not only defends the underbody from corrosion but also protects the engine and transmission as well! Less rusting coupled with slower wear and tear can surely add years to the lifespan of your vehicle.
There would be fewer dents, dings and scratches on the undercarriage for you to fret about.
Cons of Undercoating
- It is less helpful if corrosion is already present
For an undercoating to be the most effective, it should be in place before the underbelly of your car begins to rust. If you apply it over corrosion, you will still isolate the metal from further moisture and airflow, which is good, but the existing oxidizing/rusting process will still continue to occur. After rust is already present, applying an undercoating will slow the continuation of the corrosion process and will make your vehicle look better… until the rust breaks its way through the layer of undercoating you’ve applied. If you have rust present, it is better to remove the rust and then apply the undercoating.
- It adds weight to the vehicle
Although the amount of weight added to a vehicle with an undercoating is minimal (between 10 to 20 pounds for most vehicles), there is a small element of fuel economy to consider. When your vehicle weighs more, the distance you can travel on a single tank of fuel is reduced. The undercoating might reduce your efficiency by up to one mile per gallon, which creates a small additional fuel cost over time. Still, the effect on mileage of this additional weight is negligible compared to the effect a driver can have by the way they drive.
- It must be reapplied every 3 to 5 years for the best results
The only way for an undercoating to provide ongoing protection for your vehicle is to have the service repeated frequently. Most owners can have a new layer applied in about 5 years without worrying about their underbelly being compromised. In salty or destructive environments, however, you may need to have a new undercoating applied every 3 years for the best results.