If you’ve ever tried to install sound deadening mats in your car, you know exactly how exasperating that is. In previous articles, I tried to explain how you can quickly and easily install them under the hood, and in doors, which can be especially tricky. But what if it didn’t have to be? Some people may find applying sound deadening sprays easier.
There are several liquid sound deadening products on the market right now. You might not even know which one is worth getting. So, I thought I should say my piece on them as well.
Fair is fair: since I wrote so many articles comparing and reviewing the best sound deadening materials on the market, I might as well present some other options. To that end, I found two of the most well-known sound deadening sprays for cars and a pair of lesser-known alternatives. Aside from reviewing the four products, I’ll also explain how you can apply them. But first, let’s see how spray deadeners compare to mats.
Pros and Cons of Sound Deadening Sprays
Having explained the benefits of sound deadening materials and how you can install them in previous articles, I won’t dwell on them too much. However, I will start by pointing out that even the most effective sound deadeners, like Dynamat or Noico, are pretty much a hassle to install.
Dynamat, for all its advantages, is notoriously difficult to cut and position. In general, the thing that makes sound deadening mats so effective is their thickness. However, that same thickness can make them unwieldy, to the point that some people even injure themselves trying to cut them. With a sound deadening spray, you don’t need to cut or position anything.
Aside from the cutting process, sound deadening mats also come with an adhesive layer that can be difficult to navigate. And though I’d recommend that you wear gloves when embarking on any automotive soundproofing project, most liquid deadeners are much easier to remove from the skin than glue is. Even removing sound deadening mats from a car is similarly difficult, since their adhesive layer is built to last. Also, many mats oxidize if they get wet, which can damage the sheet metal of the car.
Also, unlike with sound deadening mats, a spray would allow you to completely, evenly, and easily cover the entirety of your car. While the process of installing mats can often take days to complete, a spray can be applied faster.
Two gallons of liquid deadener will cover about 45 ft2 at 40 mils, or 1mm thickness. That amount of product typically goes for just under $150, so you can calculate how much product you’d need. Also, that price-to-quantity ratio actually makes liquid sound deadening products cheaper than Dynamat. However, since sprays are pretty new and untested, mats may still be more effective.
3 Most Well-Known Sound Deadening Sprays (Reviews)
Still, we can’t completely disregard sound deadening sprays, especially since we haven’t seen what they can do yet! As I have previously mentioned, I’ve found four sprays to choose from. So let’s see what each of them does before I explained how they’re applied.
LizardSkin 50115 Sound Control Ceramic Insulation
When I started looking into sound deadening sprays, Lizard Skin products were one of the first ones that popped up. The company actually makes three different spray products. You’re supposed to apply their thermal insulation spray first, then the sound control — and seal everything with a top coat.
But I suppose the Sound Control spray should be enough on its own. For the sake of transparency, I should say that most of my insight into this product comes from user reviews and the manufacturer’s website. And, actually, the overwhelmingly positive user reviews were more helpful in determining the efficacy of this product.
Essentially, the only thing the manufacturer says about the way that this spray works is in the product name: it’s liquid ceramic insulation. As such, the spray should perform very well in hot conditions and the thin overlay it will leave on top of sheet metal in your car should be pretty scratch-resistant and waterproof as well.
The manufacturer also says that the spray is environmentally friendly, non-toxic and fire-resistant. By all accounts, Sound Control is lightweight but effective, but if you ever need to remove it, it comes off with soap and water. The spray is black, so you’ll actually be able to see it as you apply it, and if you decide to take it off.
As far as I can tell, this spray is as effective as some mats. The thin veil it leaves over the sheet metal prevents vibrations in a similar way a mat would. In addition, it’s also good at reducing outside noise as well, according to user reviews. Later, I’ll talk about how you can apply Lizard Skin Sound Control. But for now, we can move on to the other spray products.
Design Engineering Boom Mat Spray-On
The Boom Mat Spray-On is another heat-resistant sound deadener. According to the product packaging, it eliminates road noise, enhances audio performance, and dampens vibrations. Of course, these are all claims I was familiar with: I’ve seen them often enough when reviewing sound deadening mats.
Still, if the product is anything like the previous one, it should work as well. A single 18 ounce can is supposedly enough to cover about 20 ft2, which is definitely a bolder claim than the gallon per 20 ft2 we’ve previously seen. Will such a thin film of the stuff work?
According to user reviews, yes — this spray should decrease noise and vibrations. Besides, you can also layer the product on top of itself to get the most from it. Still, I don’t believe that it could be as effective as a mat, or even Lizard Skin.
Customers had also complained of a strong rubbery odor, which is to be expected, since it’s a rubber-based product. Also, asphalt-based mats emit a similar scent as well.
The cost of this product remains consistent with my earlier estimate — 2 gallons should still cost under $150. However, this product is available in cans of 18 ounces, so it may seem cheaper than the liquid sound deadeners you can find in buckets.
The fact that the product is in a pressurized can, and the fact that it emits a strong scent is concerning. The manufacturer thinks so too — they included a “flammable vapor” warning on the can.
3M 03584 Professional Grade Rubberized Undercoating
Much like the previous spray-on sound deadener, 3M Undercoating comes in a can. However, it’s much more modest about the surface area the 16 ounces of the product can cover — only about 6 ft2 at most. The price is still consistent with my original estimate.
Still, just because the manufacturer accurately predicted the area their product can cover doesn’t mean that it’s without its flaws. Firstly, just like the previous spray, it will definitely be less effective than most mats. Also, like the previous product, it may emit a certain odor since it is asphalt-based.
I should mention that the primary purpose of this spray isn’t sound deadening at all. Rather, it mostly promises to protect your vehicle from rust, corrosion, and even salt during winter. However, you’ll need to be careful how you apply these waterproof sprays if you’re really looking to prevent rusting. I’ll explain how you should prep the surface you’re covering in the following section of this article.
Also, unlike sprays like Lizard Skin, this 3M product seems pretty difficult to get rid of. So protective gear might be in order when you get around to applying it. But this is also something I’ll discuss later in the article. For now, I’ve got one last product to review.
Two Bonus Sound Deadeners
During my research, I also came across two more liquid sound deadeners I won’t dedicate too much space to. I decided to skip them mostly because they’re not technically spray products.
- The GT Sound Control Liqui-Damp looks like a pretty good sound deadener, and it was specifically made for automotive soundproofing. However, I can’t count it as a spray because you’re supposed to apply it with a brush. The brush, along with a degreaser, latex gloves, and some extras, come with the gallon bucket of product which can cover 75 ft2. The product resembles drywall mud, so you should thin out the product before applying it.
- The Dead Stop Liquid Sound Deadener is a similarly thick product. So you can apply it straight from the gallon container, or thin it out with water. I decided to skip it not only because you can’t spray it on but also because I could only find it on GT Sound Control’s website, rather than on a regular online retailer site. However, these two still cost about the same per gallon as the other liquid sound deadeners on my list.
Now let’s see how you can apply the spray sound deadeners before I wrap this article up.
4-Step Application Guide for Car Sprays
Step 1: Prep the Car
Just like when you want to install sound deadening mats, you’re going to need to get to the sheet metal of the car. For that, I’m going to point you to my article on soundproofing doors and under the hood. The doors can be especially tricky to take apart, so I advise you to do your research beforehand. You’ll also have to take off the headliner and get rid of the seats and carpeting if you intend to go all in.
Once you’re down to the bare metal, you’ll want to make sure that it’s clean and rust-free. All of these sprays are going to waterproof your car to some extent, which can actually be detrimental if the metal is already rusted.
If you’ve got some surface rust, you can just sand it off. In fact, you should sand down the whole surface you’re working on. But if you’ve got more rust damage, you may need to treat it with a rust encapsulator.
Once you’ve sanded the surface, clean it off with a clean, dry rag. If there’s some oil or grease, you can even use alcohol or a degreasing agent.
Step 2: Assemble the Materials
Alright, these instructions are pretty basic. Wear clothes you don’t care about, lay down some protection, and cover the steering wheel if you’re going to be spraying the roof. If you’re working with one of the products that comes in a can, you should consider wearing a face mask, and perhaps a hat.
However, if you’re applying something like the Lizard Skin Sound Control, you should get your spray gun and a mixer. If you don’t have them, the company sells their own kit which includes a spray nozzle, a canister, a mixing drill tip, and a wet mil gauge. As I have previously mentioned, Lizard Skin products are water-soluble. So you’ll be able to clean the spray gun off after you finish.
Once you’ve got everything, you need to mix the Lizard Skin before applying. Put the bucket on cardboard or plastic and open it. Plug in your mixing drill bit and put the drill in reverse, then slowly mix the contents of the bucket for a few minutes.
When you are pouring the Sound Control into the spray gun canister, make sure to pour it towards the label if you don’t want it to drip on the instructions on the back of the bucket.
Step 3: Apply the Sound Deadener
Again, if you’re using the pressurized canned sprays, you’ll have less work. Put your mask on and keep the can at least 8 inches away from the surface you’re spraying. The spray should be dry after about 20 minutes, so you’ll be able to reapply it at that point. After about 6 hours, you’ll even be able to paint over it, or set it with a polish. However, that’s not necessary.
If you’re using Lizard Skin or a similar product, plug in your spray gun and get to work. Expect to see a splatter texture since the gray liquid is much more substantial than the stuff that comes out of a can. Spray the Sound Control evenly across the surface.
Once you finish, you can check how deep your layer is with the wet mil gauge or just a piece of wire. You want to get your first layer about 20 mils thick. After 30 minutes to an hour, or when the layer is dry to the touch, you can reapply another 20 mils. And once that’s done, you can even put Lizard Skin’s thermal insulation on top.
Both products are gray when wet but closer to black when dry, and they both have some texture. If you don’t like that, you could probably top them with a primer, paint, or a polish.
Step 4: Put Everything Back
Take all the steps you took to disassemble the car to return everything where it belongs.
More on Sound Deadening Sprays vs. Mats
Well, I’ve made up my mind. Sound deadening sprays can be a great and easy solution. They certainly take less effort to apply than sound deadening mats. However, I do have a few gripes.
Firstly, manufacturers are going to have to step it up in a big way. There can’t be only three serious contenders on the market. Secondly, spray deadeners have a reputation for chipping, which is simply unacceptable from a product which is supposed to fend off rust.
Also, the rubbery scent on some of these must be fixed. As of right now, Lizard Skin is the only one of the three products I have mentioned which doesn’t have a smell. However, it’s the hardest one to apply, though still comparatively easier than installing a mat.
Once there are more products on the market, I’m sure companies will find a way to solve these issues. And then, we’ll have ourselves a great way to soundproof our vehicles easily and cheaply.