Alternative Sound Deadening.

[willindsay]

I've done a lot of research on the best bang for your buck sound deadening material that was comparable to Dynamat. Time and time I kept reading about this stuff from Lowes called Peal and Seal. It is 40mil thick and from what I've read it is exactly the same as the original Dynamat just a heck of a lot cheaper.

Here's what I picked up at Lowes to install it in my car.

I got both items from Lowes for just over 20$. The roll is 6in by 24ft and should be plenty to do 4 doors.

The first step to this is going to be removing your door panel. (If you're not sure how to do this just search the forum)
Under the door panel will be a plastic vapor barrier that you will need to remove. Once you are done you will have a door that looks like this..


Since the door is probably dirty it's a good idea to clean it fairly well to help the product adhere well.

Once the door is clean you can start cutting the Peal and Seal to size. I did this with a mini box cutter.


Once it is cut use a heat gun or powerful hair dryer to heat it up and the area where you are going to apply it.

It doesn't take long to heat up to a point where it burns to touch it so move quick or wear gloves so you don't burn yourself.

Once you've got it on the door take the roller you acquired from the wall paper isle of Lowes and apply plenty of pressure to adhere it to the door.


Repeat this process till you have covered at least 25% of the area on the door making sure to keep it where it will be hidden by the door panel. Once you are done you should have something that look like this.


Replace your door panel and go do your other 3 doors and the hatch.

Now just as a fair warning if you don't heat up the peal and seal before applying it it has been know to not adhere well. Also a few people have cited that in extreme heat it can produce a unpleasant smell. I have yet to have either problem and it has been over 90* for several days and my car spends about 6hrs a day in direct sunlight completely closed up while I'm at work.

[AlexSport'00]

Nice write up!

[Crutchfield Vlad]

Awesome, I might just have to check this stuff out.

[Jason c]

Just curious why you didn't apply it inside the door on the outer skin. Seems like that is where most of the vibrations would be since it is big and flat.

[willindsay]

Originally Posted by Jason c

Just curious why you didn't apply it inside the door on the outer skin. Seems like that is where most of the vibrations would be since it is big and flat.

I didn't place it on the outer skim because I read that adding it to the inside of an exterior panel will make it more susceptible to dent.

Also when I was thinking about it a solid flat piece of metal wouldn't have many vibrations one with a bunch of holes would because it is less stable. Idk if I"m right in my thinking but that's why I did it that way, plus all the pics I saw of it on doors had it on the interior panel.

[Keeper0311]

How well did it deaden the sound.

[taylorpro]

good right up OP. the only problem some have with peel and seal is the fact it's asphalt based. not butyl like some of the higher end brands. If you guys are looking for the cheapest alternative to also get the best quality materials, check out audiotechnix.com. Really awesome product at a very competitive price.

[willindsay]

Originally Posted by Keeper0311

How well did it deaden the sound.

I've only had time to do the driver door so far and it makes a bit of difference. I figure by the time I get all the doors finished it will be a significant difference.

[ranger7ltr]

And I lined both the inside and outside of the doors and the panels that are hidden by the body plastic...It has made the Explorer extremely quiet inside to the point that I can use a bluetooth radio for my phone in my truck and the other party does not hear any road noise...

I also lined the roof and the floor and firewall with the Peel n Seal...I have had it in my Explorer for over 2 years and the Ranger for over ten years and in the Texas heat there is no smell I can notice...

[SilverSPL]

FYI I've heard that after a while on very hot days the peal and seal will come off. Might want to check after the summer and see if it's still on.

[willindsay]

Originally Posted by SilverSPL

FYI I've heard that after a while on very hot days the peal and seal will come off. Might want to check after the summer and see if it's still on.

It's still holding strong.

[willindsay]

Well I finally got around to doing another door. I also decided to put some one the flat outside panel of the doors too.

So far the front door is holding strong. I forgot to take a pic of it but it's pretty much the same. I also added some more since I had the panel off to fix an unrelated problem.

Here's my Rear drivers door done.
Before


After




I can tell a difference after doing this door, most of the road noise is now coming from the passenger side. I'm hoping to get another door done this coming weekend.

Oh and in case anyone wondered how this stuff handles heat. I recently used it as a heat barrier for a Aux Fuse/Relay box.


It's been on for about 2 weeks now and hasn't moved. Just as full disclosure though it is on a plastic box but I don't think that matters.

[Keeper0311]

Well you have convinced me to give it a shot. I'll have to look around for a similar product.

[willindsay]

Originally Posted by Keeper0311

Well you have convinced me to give it a shot. I'll have to look around for a similar product.

If you've got a Lowe's near they will have it. Home depot also has a product that is pretty much the same but I don't remember the name of it.

Oh I also forgot to note that after 2 doors I have about 6ft left so my initial estimates were a little off. 2 rolls should be more than enough though.

[2TimingTom]

This stuff get poo-pooed on over at DIY Mobile Audio, although I'm not entirely sure why.

I've used it in the past. Works OK. No smells. But when I used it in the cargo area of my VUE right by the muffler, it does sorta melt. But it's out of the way and under the carpet so I'm not concerned. Any other location it holds up fine to heat.

To maximize sound deadening, you need to also use it with some closed cell foam and ideally another mass layer.

[willindsay]

Originally Posted by 2TimingTom

This stuff get poo-pooed on over at DIY Mobile Audio, although I'm not entirely sure why.

I've used it in the past. Works OK. No smells. But when I used it in the cargo area of my VUE right by the muffler, it does sorta melt. But it's out of the way and under the carpet so I'm not concerned. Any other location it holds up fine to heat.

To maximize sound deadening, you need to also use it with some closed cell foam and ideally another mass layer.

I noticed when I was researching this most every audio based site said this stuff was junk everywhere else had great reviews. Best guess is that it's just a bunch of audio guys that think if it ain't specifically made for audio it's not good.

[Mathematics]

Nice write up, I would be *really* careful/paranoid about using this stuff in your engine bay though. It does get gooey at high temps and doesn't really act as a heat barrier - might be safe for sound deadening applications internal to the car, but the engine bay is a completely different environment.

I am not a huge fan of this stuff as I've seen it come loose on vertical surfaces. I've used it on the floor of a few cars where you know its not going anywhere if it heats up, but will use one of the butyl-based brands for vertical surfaces. To each their own though, the results vs. cost ratio on this stuff is hard to argue with.

[willindsay]

Originally Posted by Mathematics

Nice write up, I would be *really* careful/paranoid about using this stuff in your engine bay though. It does get gooey at high temps and doesn't really act as a heat barrier - might be safe for sound deadening applications internal to the car, but the engine bay is a completely different environment.

I am not a huge fan of this stuff as I've seen it come loose on vertical surfaces. I've used it on the floor of a few cars where you know its not going anywhere if it heats up, but will use one of the butyl-based brands for vertical surfaces. To each their own though, the results vs. cost ratio on this stuff is hard to argue with.

No problems so far and the stuff in the engine bay hasn't moved at all. I'll keep an eye on it though.


Oh I got another door covered today. I was gonna do the last one but I ran out of material.

And just a suggestion replace the bushing's in your power windows while you've got the panel off. It's cheap and you've already got it tore apart. I used ball bearings in mine so I won't ever have to service them again.

[Mathematics]

Originally Posted by 2TimingTom

This stuff get poo-pooed on over at DIY Mobile Audio, although I'm not entirely sure why.

Here's the best all-in-one-place lowdown I've found of asphalt-based products vs. butyl-based products: http://www.diymobileaudio.com/forum/1700914-post12.html

Originally Posted by Jazzi

Damping Materials: name-brand product vs asphalt-based alternative

When I started learning about damping resonances and sheet metal, I was (like many people) surprised by how expensive materials like Dynamat, Hushmat and other name-brand CLD tiles were. Many forum warriors were convinced it was a grand scam and we could easily substitute products from other industries with similar materials for much less money. But there was much controversy about asphalt vs butyl, and weather or not the presence of foil backing made a difference, or how thick it should be, and so on.

At the time, I was in the middle of a physics class dealing with light, optics, waves and whatnot. As an extra credit project I ran an experiment to see how effective a single layer of asphalt-based roofing sealer (Grace Ice and Water Seal as commonly suggested during my reading) would be compared to a single layer of Stinger Roadkill (the first name-brand product I found at a local shop). The results were astounding.

If you are interested in the specifics, this report from E-A-R Specialty Composites is a great primer on the difference between a free-layer damping system (FLD) and a constrained-layer damping system (CLD). One of their illustrations is below. From what I understand, it seems a single very thin constrained layer sandwiched between two metals that are similar to eachother will give the best results. So when shopping for a damping tile, find one with excellent adhesion, high temperature rating, a thin viscoelastic (usually butyl) layer, and a thick aluminum backing (ie. almost every name-brand product meets this).


Image borrowed from E-A-R Specialty Composites
Understanding Damping, E-A-R Specialty Composites

In this example, a single layer of asphalt-based roofing material material with adhesive on one side attached to sheet metal is a free-layer damping system. A layer of Stinger Roadkill is a constrained-layer damping system because it sandwiches the butyl between the aluminum backing and the sheet metal of the car. Hopefully the above diagram helps.

The experiment was simple: measure the damping factor of resonances of my car door as it came from the factory, after applying asphalt-based product, and again after removing the asphalt and treating it with Roadkill. In addition, I would test a single piece of sheet metal on the bench to see if there was a significant difference between trying to damp the resonances of my car door (a complicated system) vs a single sheet of steel (a simple system).

Damping factor is easy to visualize using an RTA and some division. No complicated maths here. Viscoelastic Damping 101, Roush Industries is an article describing how to calculate it, and here is an example from TrueRTA in my measurements.


A sample calculation: damping factor of 95hz resonant peak: η = (106hz - 82hz) / 95hz = 0.25
(a higher number is better)



Above is test 1: this is what the outer door skin looked like from the factory. Notice the single free-layer damping material that has been applied in the top-left corner.



Above is test 2: this is two layers of asphalt-based roofing applied over the top of the factory damping material.



Above is test 3: all asphalt and factory damping materials have been removed, and about half of all accessible surface area has been treated with Stinger Roadkill, a constrained-layer damping material.

After each treatment the doors were fully assembled before taking measurements. Essentially I hammered the outside of the door using a soft mallet and recorded the sound from the inside, used TrueRTA to help calculate the damping factor, then made some graphs. First is the test using the car, the second graph is from a single piece of sheet metal suspended in air, and tested the same way.


Above is damping factor of the car door untreated from the factory, after applying a single layer of asphalt-based roofing material (Grace), after a single layer of name-brand product (Stinger), and finally with additional Stinger Roadkill plus a layer of MLV for sound isolation.
(higher is better)



Above is the bench test of a single piece of sheet metal. (higher is better)

In the bench test, the result is obvious. A single layer of asphalt-based roofing material provides some damping to the sheet metal, an increase of about 29% average damping factor. But a single layer of CLD is phenomenally more effective with an average increase of 770%! So, myth busted, Grace Ice & Water Shield may be a fine roofing material, but it is nearly worthless as a damping material.

In the car door test, the results are much less clear. Two layers of Grace yields an average decrease (!) in damping factor by 1%, but a single layer of Roadkill only has an increase of 13% on average. Confused by this, I tried to go crazy and added more Roadkill to the outer door skin, applied some to the inner door skin, and then added a mass-loaded-vinyl barrier to the inner door skin to further isolate noise and prevent it from entering the cabin. Even with these stronger measures I only saw an increase of 26% damping over the factory car door.

So what is going on? Clearly from the bench test a single layer of Roadkill (on 25% surface area) should have a drastic effect on damping factor for sheet metal. However the car door behaves differently. I believe the car door having (1) an outer wall of sheet metal and (2) an inner wall of sheet metal and (3) another inner wall of plastic and vinyl door card and (4) air chambers between all these layers are responsible. I believe the air chambers themselves have resonances that cannot be affected by damping the sheet metal and must be addressed other ways.

Conclusion? Buy a CLD tile from a common brand (or sounddeadenershowdown) and apply it in a single layer over about 25% to 50% surface area for excellent results (adding more doesn't increase benefits for the high additional cost). Also, further study needed to find sources of resonance in car doors. I'll have measurements for a new idea to address this soon.

Long story short there is a measurable difference between the two. BUT the CLD is just for damping - I'll second the comment on using closed cell foam & mass-loaded vinyl on top of the CLD. I added both to my mounty over the CLD and it was a night & day difference in interior noise. Amazing how much better your speakers will sound when they're not competing with anything else to get sound to your ears.

[College Student]

I only see one problem with his test. We have been talking about peel and seal which has an aluminum skin like the brand name where as the non-brand name he used was basically just the rubber portion.