Car Undercoating Sound Deadening

Deaden Road Noise with Car Undercoating Soundproofing

Deaden Road Noise with Car Undercoating Soundproofing

Soundproofing your car is a step-by-step process that starts from the ground up. If you're looking for an undercoating and you’re also dealing with annoying road noise, either because you drive over a lot of low quality roads or because you drive a truck/hot rod/performance vehicle, a spray on sound deadener will do the trick.

There are a lot of solutions out there for undercoating your vehicle, but for effective soundproofing that lasts, there are a few key points to keep in mind:

  • Materials matter. If you apply an asphalt-based or wax undercoating, you get what you pay for. Asphalt is tough, but a less effective deadener. Wax never truly hardens and often needs to be stripped and re-applied yearly.
  • Product type matters. Many folks have sprayed the underside of their car with a rubberized undercoating and expected better sound deadening. While the rubberized undercoating is awesome for protection from rust, moisture, and dings, it’s a mediocre at-best vibration damper.
  • There isn’t one cure-all solution. Although using a high-quality deadener on a vehicle can take a big chunk out of road noise, undercoating isn’t the end all solution. It can make a difference but is also just a piece to the puzzle.

Read on to learn more about undercoating, whether or not it’s a good solution for your vehicle, and how to do it properly.

Soundproofing your car is a step-by-step process that starts from the ground up. If you're looking for an undercoating and you’re also dealing with annoying road noise, either because you drive over a lot of low quality roads or because you drive a truck/hot rod/performance vehicle, a spray on sound deadener will do the trick.

There are a lot of solutions out there for undercoating your vehicle, but for effective soundproofing that lasts, there are a few key points to keep in mind:

  • Materials matter. If you apply an asphalt-based or wax undercoating, you get what you pay for. Asphalt is tough, but a less effective deadener. Wax never truly hardens and often needs to be stripped and re-applied yearly.
  • Product type matters. Many folks have sprayed the underside of their car with a rubberized undercoating and expected better sound deadening. While the rubberized undercoating is awesome for protection from rust, moisture, and dings, it’s a mediocre at-best vibration damper.
  • There isn’t one cure-all solution. Although using a high-quality deadener on a vehicle can take a big chunk out of road noise, undercoating isn’t the end all solution. It can make a difference but is also just a piece to the puzzle.

Read on to learn more about undercoating, whether or not it’s a good solution for your vehicle, and how to do it properly.

What is a Car Undercoating?

Undercoating is an extra layer of aftermarket protection and insulation you can choose to apply to the undercarriage of your vehicle, which includes parts of the chassis, exhaust, suspension, and wheel wells. Manufacturers may apply undercoating at the factory, but in certain environments it can make sense to re-apply or to upgrade.

undercarriage of a car

Protect the Undercarriage

If you think your vehicle will need extra protection, it's best to apply a protective undercoating as soon as you buy it. Otherwise, you need to clean the undercarriage thoroughly to avoid just covering up the dirt and grime already on there. By protecting the exposed parts of your car from rust as well as dirt, grime, dust, salt, and everything else you’ll find on the road, you can extend its life and prevent maintenance issues down the road.

Deaden Road Noise

Road noise is caused by a combination of your car's structural construction, the tires you're driving on, and the condition of the road. Applying a sound deadening undercoating will reduce the vibrations as you drive, making a big dent in your car's structural noise. When your vehicle is in motion, the structural noise it creates is a result of its moving parts. Vibrations, rattles, metal-on-metal sounds — they’re all structural noise. The way to combat that noise on the underside of your vehicle is with a liquid deadener undercoating.

It would seem obvious for car manufacturers to install high-quality undercoating to vehicles off the line, but that’s usually not the case. Instead, it’s left on the consumer to apply deadening and protection to their vehicle’s undercarriage.

Will Undercoating Reduce Noise in My Car?

If you drive on dirt or gravel roads, have performance tires, or drive a hot rod or truck, undercoating will reduce noise in your car. Even If you’re not in one of these situations, if you’re experiencing road noise, an undercoat of sound deadener may be a good solution for you. A sound deadening undercoating will:

  • Reduce overall structural noise from your vehicle
  • Shield critical parts of your car from rust
  • Add thermal insulation to reduce heat transfer

At Second Skin Audio, we've formulated an undercoating we call Spectrum, a liquid deadener that can be applied with a brush, roller, or spray gun. For applying to a vehicle’s undercarriage, a spray gun is the best method to make quick work of the project.

Spectrum is a high heat, water based viscoelastic polymer that when sprayed, results in a thick coating that is soft enough to deaden noise but hard enough to stand up to wear and tear. Although Spectrum is tough, it can be damaged by heavy impact, so we recommend to apply an additional protective layer if you anticipate heavy abuse.

Sound Deadening Undercoating Rubberized Undercoating

Rust & Corrosion Protection

Effective Vibration Damping

Grime, Salt, & Dirt Protection

Heavy Impact Protection

Effective Thermal Insulation

Easy to Spray On

How to Apply Sound Deadening Undercoating

Step 1: Prepare the Application Surface

One of the goals with undercoating is to protect your car from dirt and rust, and the best way to start your project is by by cleaning the undercarriage. Wash away as much dirt and grime as possible (we recommend cleaning with denatured alcohol) and remember to wipe the entire surface dry. Moisture is the enemy, you don’t want to apply your undercoating with moisture trapped between it and the car.

If you see rust, you’ll need to scrub it away with a wire brush. If you want to use a primer to the areas affected by rust, we recommend POR-15. Let the primer cure for about a day.

Step 2: Install Spectrum

If you’ve decided on using Spectrum, you’ll need about 3 gallons for your average sized vehicle (60 sq ft). Some larger vehicles may require another gallon. Spectrum comes with a long straw and short straw — if you decide to spray on sound deadener, use the short straw when working upside down.

Apply Spectrum to the entire underbody of the vehicle and make sure to stay at least 2 inches clear of any heat source. Most exhaust systems hang at least 2 inches from the vehicle, but if that’s not the case with you, make sure you spray around the exhaust. Wait about 24 hours for Spectrum to cure.

Once you have finished spraying Spectrum liquid deadener, you’re set. Spectrum will bond for the life of the vehicle. If you want to add a rubberized undercoating on time of your deader to protect from heavy impacts, wait a week to allow Spectrum time to cure.

Spectrum liquid deadener

Step 3: Install Thermal Block (Optional)

Spectrum is a good thermal insulator, so there’s a good chance it solves any heat issues too. If you are dealing with a lot of heat, you may want to consider Thermal Block — our signature aluminum reflective heat shield. The peel and stick sheets are thin, flexible, and easy to install on top of Spectrum or directly to the metal. Just press firmly to adhere Thermal Block behind the muffler, exhaust, and catalytic converter with the foil side facing the heat source. If you have room, to cut Thermal Block twice as wide as the pipe, muffler, etc.

Go Deeper with Our Ultimate Car Insulation Guide

Now that you’ve got the basics of what to look for in an undercoating, where to install it, and how to install it, you’re ready to go. As we mentioned before if your primary goal is noise reduction, undercoating is just one piece of the car soundproofing puzzle. Check out our complete guide to automotive insulation to learn more about what you can do to turn your car into a soundproof bubble of comfort.