How Much Sound Deadener
- Thread starter Gonzo
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Even though asphalt adhesive and butyl adhesive look a lot alike, they are very different. Butyl adhesive is what's called non-curing - it stays sort of rubber and flexible for ever. Asphalt is only soft and flexible because it contains what are basically solvents. When you smell that classic tar odor, it is really those solvents or volatile organic compounds or VOCs evaporating. They are toxic.Gonzo said:
The more the VOCs leave the product, the less flexible it becomes and the less effective it is as a vibration damper. Even when it's fresh, asphalt is a much worse vibration damper than butyl.
The cheapest butyl is probably eDead or Sound Destroyer Problem is, neither one has a real foil facing layer. Both use Mylar which is cheaper and MUCH less effective. The cheapest butyl mat I would use is RAAMmat - decent adhesive and decent foil thickness. Damplifier is really cream of the crop - great adhesive and nice thick foil. Dynamat Xtreme is somewhere between RAAMmat and Damplifier in quality. It's usually very expensive, but if you have a local hookup, it can be a good deal.
I suggest that if these options seem too expensive, just use less. You will get a better result usng half as uch of a good quality product as you will twice as much roofing. You also don't risk having the mat melt of fall of.
(I linked most of the products I listed, they just aren't showing up too well.)
the cons far out weigh the pros with the liquid stuff...the solid stuff is the best way to go for the DIY'er...
rudy is calling fatmat liars.... (i dont know...i dont have industry ties)...can someone call out fatmat?
rudy...send them an email...we all want to know...
dont forget you always have to weigh cost vs. performance...
rudy is calling fatmat liars.... (i dont know...i dont have industry ties)...can someone call out fatmat?
rudy...send them an email...we all want to know...
dont forget you always have to weigh cost vs. performance...
Liquids are slightly less effective, but not terribly so. They do have to be applied at roughly the same thickness as the mats - 1.2-2mm. This means several coats, with drying time between coats. It will take longer. If you have a compressor and a schutz gun it can go pretty quickly. Otherwise you can brush them on. Mats are generally less time consuming and easier to do in a druveway with minimal equipment.Gonzo said:
They won't answer my questions. I can't swear they are lying in this particular case, but they have lied to me in the past. I wrote Sound Deadener Showdown and called them out. If you call them, they will tell you that I work for RAAMmat, which would be strange since I have Second Skin and Cascade in my car.kaace said:
I work for myself and have no involvement in the sound deadening industry other than having written Sound Deadener Showdown That project has now been read by something like 30,000 people, so I have inadvertantly ended up having a lot of influence in the industry.kaace said:who do you work for?
I only got started with this because I was looking for a way to make my Civic more pleasant to drive. I read all of the forum posts I could and wanted to find out if the common assertion that Peel & Seal was the same thing as Dynamat were true. This was more than a year ago and the market was much more chaotic than it is now. Many, if not most, of the companies selling these products were intentionally providing vague and misleading specifications. It was very difficult to come to any sort of informed decision.
Since there were no comparative reviews anywhere, I decided to do it myself - rather naively believing I could do it in a day or two. I also thought that 10 or 20 other people might find it interesting. It got completely out of hand, but a great many people have found the effort helpful.
That is correct, but as in most things, there are some complicateing factors. Some butyl mats use a better and more effective adhesive than others. These also perform better as vibration dampers.kaace said:
Secondly, sound deadening mats work in several ways. They add mass to the panels to which they are attached, the stiffen panels and they convert sound energy to heat through internal frictions. Part of the reason foil clad mats are more effective than liquids is that stresses at the foil/adhesive interface enhance that last effect. The thicker and strong the foil, the better.
Finally, if you cover a significant area with these things, you are creating a barrier to noise. The most effective barriers combine layers of different densities and elasticities. Foil is much more effective here as well.
Asphalt has additional problems that I won't go into now, but it is very sensitive to heat exposure and becomes more so over time. It frequently fails in a car during the summer. It is common to have it remain stable for a summer or two and then fail the next summer. I have never had a report of a butyl mat failing.
Here's a quick hierarchy: Any butyl is better than asphalt. Butyl with foil is better than butyl with Mylar or PE. Higher quality adhesives have value as do thicker and more rigid foil layers. Those things both add to the cost.
I'm not sure what you mean by this. One thing you need to keep in mind is that all of these companies, with the probable exception of Dynamic Control, Scosche and maybe Hushmat are one person operations. A few have a relative helping out. FatMat operates out of a garage in Cory, PA. For years they made a decent living by buying Peel & Seal and reselling it with the claim that it was BETTER than Dynamat Xtreme. Many of these characters were doing the exact same thing. Then I came along and pointed out that they were lying. It cost them a lot of money.kaace said:thou doth protest too much...
I'm not qualified to do this, I just ran some simple tests that revealed just how dishonest some of these people were being. My "protestation" results from having been lied to before and having been told by more than one person that when called, FatMat is telling people that I am bad mouthing their product because I woek for RAAMmat. These are examples of there lies. Is it possible that they changed the composition of FatMat? Yes, I can't say for certain, but they have a history that not only leads me believe they have not. They are free to submit a sample or have somebody submit one on their behalf if they don't trust me - and have not. I bought the first sampe I tested and it took nearly 3 months for them to ship it from PA to MD. Every time I called, I was told it had just shipped. Here's a link to the feedback for an eBay ID they had to abondon because it was getting so bad. At this point, I'm not willing to give them another cent to find out if they have changed their ways or not. If they send me a sample, I will treat it fairly.
Drop a piece in a jar with a few ounces of turpentine or acetone in it. Let it sit for 15-20 minutes. If it's butyl, the liquid will stay clear - maybe a little bit of black sediment. If it's asphalt, the liquid will turn brown and the adhesive will disolve.Gonzo said:
I can't even tell you how much I have in my car. I started by buying about 150 square feet of mat. I also used closed cell foam on top of every place I installed mat. That is a really important step. It seems to make the whole thing work twice as well, much less noise and definitely improves sound quality. THat first phase made a huge difference and I was really pleased with the effort.
What happened then was that the companies in this market started hearing from their customers, either complaining about how poorly a product did, or demanding that it be tested. 4 or 5 of them didn't just send the 3 6" squares I needed for testing, they send real useful quantities and invited me to use the stuff for some hands on experience. I think I now have at least 300 sf f mat, two different kinds of liquids and several different acoustical foams
Now my car is stupid quiet, so is my girlfriend's. Considering all of the time I have put into this thing, I would have been much better off just buying the extra myself, but I have earned a lot through actual use. I really have too much stuff in there, but I only learned how to get by with less through trial and error.100 - 150 sf of a good quality mat and at least as much clesed cell foam will do a good job on a Civic - an excellent job if you pay attention and don't just slap it on randmly.
i disagree with that, actually.. though i guess it depends on what sort of noise you're talking about. i'm sure it would take a lot to keep road noise out, but for audio... i don't have a crapload of dynamat and it made a pretty big difference. 
That's true. You don't have to fully cover the surfaces if you don't want to. Targetting just the weakest sections can be very effective as well.Akiahara96 said:i disagree with that, actually.. though i guess it depends on what sort of noise you're talking about. i'm sure it would take a lot to keep road noise out, but for audio... i don't have a crapload of dynamat and it made a pretty big difference.
Some of this has to do with the quality of the mat you use. On a different forum, someone is describing having to use 5 layers of butyl/Mylar eDead to equal 1 of Dynamat Xtreme.
i've never seen anything other than dynamat in person... i personally have dynamat xtreme. i'd be curious to hear the difference, but i wouldn't experiment on my car. 
K to put it in perspective, I have a 4 door with the rear deck lid, and I put approximately 8 square feet to JUST do the top of the trunk lid, and in my old car it took 20 square feet to do 2 doors fully (inside AND outside shell). I am about to do them again and I have 26 square feet to be safe, always overestimate when you soundproof anything because if you run out with your car torn apart it is a nightmare, you don't wanna cut corners. If you are doing it, do it right, you can always sell your leftovers, find a use for them somewhere else in your car, or give em to a friendGonzo said: