The Truth About Sound Deadening Spray and Paint

The Truth About Sound Deadening
Spray and Paint

Deadening vs Damping vs Dampening: A Guide to Soundproofing Your Vehicle

If you’re looking to reduce the sound in your car, one of the options you’re likely to come across is sound deadening sprays. Spray on sound deadeners and soundproof paint are convenient choices because of how quickly you can apply them. But how do they do at reducing noise in your car?

In this article, we've gone under the hood to get you the truth about sound sprays so that you can determine what’s right for your vehicle. And no, we’re not above cheesy puns. That one was pretty bad though.

Are you someone who likes to drive with the volume on your stereo turned up, but would rather hear the music instead of your car? Are you restoring an old vehicle and are concerned about driving at highway speeds in a box of metal? If so, one of the things you're going to want to consider is soundproofing your car.

However, when doing so, you’ll find that there are numerous methods available. The first key step is to stop the metal panels from vibrating and rattling. If you’ve been researching how to do this, you’ve likely come across what looks like several different methods. Some methods deaden, while others damp or dampen. What’s the difference between these methods? We’re here to provide you with a complete breakdown of how to go about soundproofing your vehicle.

What are sound sprays and paints?

When browsing the vast caverns of the internet, you're going to find a variety of different liquid products advertised as soundproofing solutions. Below are some of the most popular soundproofing products available today.


One of the most convenient and affordable options available is a spray on sound deadener. This sound deadening car spray comes in either a bucket or a can. You don’t need to be a professional to apply these products. All you have to do is throw on the proper eye and respiratory protection and begin using the product on your vehicle.

Sprays are useful because they allow you to stop rattles and vibrations in areas that otherwise would be hard to cover. Sprays also will enable you to coat your car without any seams or gaps, something that cannot be said for sound deadening mats. The best car soundproofing spray options provide both noise and heat insulation, and come in a bucket. There’s variety in bucket quality, but they tend to all be more effective than aerosol can deadeners. The products in a can are more convenient for small surface areas and cheaper, but you get what you pay for – they are much less effective due to the can’s nozzle being too small to spray true sound deadening polymers.

If you’ve already stripped the car to the metal, you should be able to spray sound deadening onto an entire vehicle in just a few hours. Most of the time will be spent waiting on the liquid to dry. Liquids are by far the easiest way to stop noise from vibrating metal if you do the right prep and have the right equipment.

SOUNDproof paint

Soundproof paint is not recommended for use in vehicles. You usually see this product used on walls in homes or in commercial spaces like hotels. While this product may look very similar to a liquid deadener – they both come in similar sized buckets and advertise reducing noise – they are intended to solve entirely different problems. The liquid deadener is designed to stop vibrations and reduce noise from rattling metal whereas the soundproof paint is designed to increase a wall’s mass to reduce the amount of noise that can pass through it.

There are some high quality soundproof paints out there, but make sure to do your research to ensure you’re actually going to solve the problem. No matter which paint you choose, if you want to make a substantial reduction in noise, you’re talking about multiple layers of paint, preferably on both sides of the wall. Paints are best at stopping high frequency noises (above 2000 Hz), so you may see less of an impact if the sounds you want to stop are on the lower end of the frequency spectrum. It’s most effective to install mass loaded vinyl and/or spray insulation in the wall when you’re doing the initial construction, but that’s not always an option. Sometimes the wall is already there! In that case, soundproof paint is worth considering because you can get good results without ripping the wall open.

The Pros and Cons of Liquid Soundproofing Products

Since soundproof paints are not often used in vehicle applications, we wanted to spend a little bit more time comparing the two that are: sound deadening sprays in a can and liquid deadener sound insulation.

Aerosol Sound Deadening Liquid Sound Deadening

 Primary Use

Deaden metal; stop noise from vibrations

Deaden metal; stop noise from vibrations

What's in it?

Liquid rubber

Water, viscoelastic acrylic polymer

How is it sold?

In an aerosol can

In a paint bucket

Does it work?

Some, but the nozzle is a limitation

Yes - that metal is dead

Will it stop heat transfer?

Minor impact; rated to 300 F

Moderate impact; rated to 400 F

Does it smell?

Badly; spray it outside

Minimal application; dries odorless

Should I spray it on my clothes?



Do you need tools?

No, very convenient

Requires spray gun, brush, or roller

Cost per Sq Ft (1 layer)

~$1 per square foot*

~$1.90 per square foot***

*We've found that you're lucky to get 15 square feet from an aerosol can product. ||| **$1.55 if purchasing 5 gallon containers

Choosing a Product

If you’re like us, a list of pros and cons can still leave you struggling to identify which product is best for your vehicle. We think our Spectrum liquid sound deadener is pretty awesome, but you know…we’re biased because we formulated it and it’s our baby. Second Skin could offer you a sound deadening spray in a can, but we’ve chosen not to because the physical limitations of an aerosol can mean that it couldn’t meet the high performance expectations we require of all our products.

But if we had to give you the other side of the story, we’d say the aerosol can products are a good option if you have a small surface area to cover, the rattling isn’t too bad, and you want something very easy to apply. There! That’s all you’re getting from us. Sorry Spectrum, we didn’t mean it! You’re the best.

Final Thoughts

Although sound deadening sprays that come in an aerosol can are convenient, they likely are not the best option for your vehicle. If you’re genuinely interested in reducing how much structural noise your car makes, you’re going to want to look for better sound deadening options. We offer a variety of high quality sound deadening mat and liquid deadening products. If you have questions about your project, let us know. Friendly advice is just 2 cents, but we usually don’t collect.