Best Soundproof material and practice...

Howdy,

I’m trying to narrow down what would be the best material for soundproofing.

Does anyone have experience with a few brands out there? Or is the general consensus on a particular brand?

Just trying to get an idea for 2 scenarios:

1. Disregard of cost for best material

2. Most cost effective material (bang for the buck)


As for best practice, is it best to “Lizardskin” + ceramic coat the firewall side of the panels and floor panels and then cover with soundproof the entire cockpit area?

Any other recommendations?

Thank you. I’m attaching an interesting article regarding the soundproof materials.

https://soundproofliving.com/automot...ing-materials/

Similar to your power steering question, you're asking for "best" when (1) Most of us will recommend what we've successfully used, and (2) No actual testing data at least in these builds between various brands. So you'll get lots of opinions but no one can really say theirs is "best" or "best practice." What I can say for me, after several builds and thousands of miles, is (1) A decent heat/sound insulation installation on the inside of the cockpit along with the carpet and I've had zero heat issues. (2) Be just as conscious of air intrusion into the cockpit. It's critical to get everything sealed up so that hot air from the engine compartment isn't coming into the cockpit. All the insulation in the world isn't going to help if hot air is flowing in. And (3) Don't underestimate that big orange ball in the sky. We get worn out from heat and sun from outside the car way before heat inside the car is an issue. Kind of goes with the territory of an open top Roadster.

Products I've used? Dynamat stuff is all good, just pricey. I used some Second Skin Damplifier Pro in my Coupe build and was very impressed, but also not particularly cheap. I've used Lizard Skin heat and sound products on all my builds and like it a lot. A good coating of both on the inside plus carpet has been my main strategy, and I've found it works fine. No additional material required. And I don't recommend it on the engine or chassis side, even though I know some do it. It's a water based product and while it dries hard I personally don't consider it hard and durable enough to be left uncovered. Plus I strongly prefer the clean look of metal (however you choose to finish it or not) and it's just not needed there in my experience.

I used the lizardskin products on my car, however it’s still a work in progress, so I can’t vouch for its effectiveness. So far, I’ve only done my top, but when I do my side & firewall panels, I plan to apply it to the back sides so that my interior is all metal.

I used Hushmat after seeing it recommended on here and doing some research. Never felt like my footboxes were getting hot in two seasons of driving. As noted above the sun will heat up absolutely everything though.

After a number of builds, I use Fatmat ordered directly from their website. It's inexpensive when compared to the the other name brands and has performed well in every car we have done.

I used dynomat+carpet on my MK4 but I wouldn't know if it makes a difference or not. All you can hear are the side pipes anyway. Ditto what edwardb says above with regards to hot air flowing in from the engine bay. I'm tracking that down now on my car.

I used Lizard Skin ceramic and sound insulation for my build. Just used it in the cockpit, including firewall. I made sure to plug up any holes prior to applying it, and tapped up any possible places it could come out. There is a decent amount of prep work. Also I had all my panels powder coated so the interior of the cockpit had to be sanded with an orbital sander. Was very happy with the results and while I only have 1k miles on the car haven't had any heat issues. Would use it again.

Soundproofing? In a Cobra with sidepipes next to your ear? Hahahahahahaha.

Heat insulation. That makes sense.

As edwardb said, most people, me included, have used precisely one product. So not many of us can really compare. But, from my years around here. My advice is be concerned more about heat control. Also, some products are heavy, which is exactly what a Cobra is not supposed to be. 50lbs is more than a 2% weight gain. I remember that someone said they used a product that added 100lbs. Doesn't sound like much, but it is significant if you are concerned with performance.

I used EZ-cool. Which is a lightweight heat barrier.

Hi, I know this is not the preferred method to apply Lizard Skin but i'm going to use a brush. Is it possible to thin the Lizard Skin down so it is more easily applied with a brush?

thanks,
Tim

I did the entire interior of my car with ThermoTec Coolmat. Pretty much the same as Dynomat and other similar products. I did it more for sound dampening. I didn't want that tin can sound in the car. It is heavy at about 40-45 lbs.

Dave

Hey Tim, I’m not an expert nor have I applied LS but the instructions are to ensure that you have a certain thickness to the product on the surface. I think they supply you with a little measuring tab that you can crosscheck that stuff with.

So in the end, I guess as long as you can ensure the thickness of the LS on the surface of the material, you might be good to go.

But then again, the demo was specific about how much stirring you had to do because of some of the components in the chemical. So I dunno.

If you haven’t seen the vid, go to the LS webpage, you’ll see it. I can see why you would opt to do that to prevent from aerating that stuff especially if you’re in a confined space and can’t go outside.

Quote:

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Originally Posted by tbl100

Hi, I know this is not the preferred method to apply Lizard Skin but i'm going to use a brush. Is it possible to thin the Lizard Skin down so it is more easily applied with a brush?

thanks,
Tim

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Quote:

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Originally Posted by tbl100

Hi, I know this is not the preferred method to apply Lizard Skin but i'm going to use a brush. Is it possible to thin the Lizard Skin down so it is more easily applied with a brush?

thanks,
Tim

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It's water based, so could be thinned a bit with water. Not sure it would be necessary though. I've brushed it on smaller pieces (both products) and while slower than spraying, can be done. I'd be afraid of not getting the required thickness if thinned though. BTW, spraying is the easy part. Literally just takes minutes to do the entire interior and trunk. And relatively easy to get the required thickness with a couple coats. The time is in the masking and prep. Just like all spray jobs.

Hey Tim,

I went to the LS FAQs and I found this:

"Can I roll or brush this product on?
We strongly recommend that the LizardSkin products be applied with the LizardSkin SuperPro Spray Application Kit. Small applications of less than 1 square foot can be brushed, though sanding after each coat may be required to ensure even coats. Please call for further instructions."

https://lizardskin.com/faq/

Quote:

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Originally Posted by tbl100

Hi, I know this is not the preferred method to apply Lizard Skin but i'm going to use a brush. Is it possible to thin the Lizard Skin down so it is more easily applied with a brush?

thanks,
Tim

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Ear plugs ! Best sound proof and cheapest out there.....jus sayin !...da Bat

As the Bat says.... don't over think it the noise comes from the wind, road and side pipes and all the sound proofing in the world will not reduce it. Put some insulation in the foot boxes and on the transmission tunnel to cut the heat, get some ear plugs and go.
David W

I used a combination of Lizard skin for heat covered with Dynamat. I have used this method in a couple of other closed cockpit cars I own with great results. I will do it again on my latest project. Regarding Dynamat for sound control, I agree with what everyone says. In an open cockpit car with side pipes it is a uphill battle. However, large aluminum panel tend to resonate and are noisy left uncovered. As well, I find that the Dynamat just gives the car a solid, finished feel. I put it on every interior aluminum surface including lining the trunk. Overkill? Maybe!

Avalanche's response was not in jest.
The loudest sounds are emanating from the sidepipe's, and from wind noise, not so much mechanical noise, or road noise. Working on the heat proofing is more practical then worrying about sound dampening. Many products mentioned will help with both of course.

I’ll +1 for the mat products. Not for cutting down sound but to help with cutting down vibrations and the tinny sound that may come along.

I too used a mat and it is great for heat and to keep the vibrations and tins sound down. Happy with my choice.

What brand did you go with?

Quote:

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Originally Posted by tt400

I too used a mat and it is great for heat and to keep the vibrations and tins sound down. Happy with my choice.

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Agree with Avalanche 325, you can't stop the sound as it is exhaust pipes & wind-noise. That said there are a lot of heat resistant products so of which have the side benefit of eliminating the tin can sound of the alloy body panels. Makes in more of a car & not a kit car.

My two products were Reflectix & Thermo-Tec. Thermo-Tec is a high temperature heat barrier that has a self stick backing. I placed it on all the surfaces that faced a heat source. Firewall, foot boxes, inside transmission tunnel, under door panels, inside the side pipe heat shields etc. Pricey but very effective. Personally tested an alloy panel with & without Thermo-Tec using a heat gun.

Reflectix is an inexpensive attic insulation. Two aluminum foil skins sandwiching a thin bubble foam center. It was applied to all the interior cockpit surfaces under the carpet.