Opinion Sought

Started by Whit, August 30, 2015, 02:25:42 PM

Previous topic - Next topic

Dave Ventresca

The Tassie Devil(le)

'72 Eldorado Convertible (LHD)
'70 Ranchero Squire (RHD)
'74 Chris Craft Gull Wing (SH)
'02 VX Series II Holden Commodore SS Sedan
(Past President Modified Chapter)

Past Cars of significance - to me
1935 Ford 3 Window Coupe
1936 Ford 5 Window Coupe
1937 Chevrolet Sports Coupe
1955 Chevrolet Convertible
1959 Ford Fairlane Ranch Wagon
1960 Cadillac CDV
1972 Cadillac Eldorado Coupe

David Greenburg

More specifically, a small, tweaked/ modified Japanese car; often a Civic, Mazda 3, Corolla etc.   
David Greenburg
'60 Eldorado Seville
'61 Fleetwood Sixty Special


Well there's many different cost effective alternatives that peform just like Dynamat but for over half the price. For instance I used this product called Peel N Seal, and something that's even better is this stuff they sell at Home Depot called U-Seal which is thicker feeling and heavier than the Peel N Seal. Both are rubberized asphalt based insulation wrap for roofing, but I have had awesome results in my cars with it including thousands of other people that use it to sound deaden the noise in their vehicles trunks, door panels, floor pan, and anywhere else you can think it works great!

The rubber stuff does add some weight and it really makes a difference in how a door feels when closing it compared without it. For instance, I had to replace a window regulator in my mother's 98 Honda Accord, the doors use absolutely no insulation at all, just a few pieces of carpet padding. So I decided well since the door panels are off, and everything is exposed, I might as well try to quiet the inside of the door the best I can to prevent road noise and give the door a more solid feeling "thunk" upon closing. So I bought a roll of U-Seal, and cover as much metal on the door as possible without blocking any holes, and after putting everything back together, the difference was amazing.

Before when you open and close the door, it sounded like a tin can, and was very light, but after applying U-Seal, the door felt like it had some weight to it, and it close solidly. It also reduced a speaker vibration in the door that would rattle some of the plastic trim, but the rattle was eliminated after sticking on U-seal.

So it really does work, I covered my entire truck and inner quarter panels with this stuff in my 94 Cadillac Fleetwood because I have  two 10 inch subwoofers in the trunk, and the vibration would rattle the outside trim and it sounded horrible. Using 2 layers of U-seal, a layer of foam adhesive padding which is basically A/C Duct wrap you can also get at Home Depot or Lowes, and a layer of carpet padding, the vibration and the sound of the bass throughput the entire car not only improved big time, but it stopped the rattles and the bass sounded tighter. It also reduced the road noise in the trunk area to literally zero.

These Cadillac Fleetwoods are already really quiet cars, but the trunk doesn't have any insulation from the factory, so it never hurts to add sound deadening material to any car especially in a luxury car like a Caddy, even a classic one. The more material, the better, the car will not only be quieter to drive, but it will feel more solid too.

Remember one can easily go through a few rolls of this stuff in no time, and it adds weight. The doors on certain year Cadillacs already weigh a ton, so adding strips of U-seal or dynamat can easily add a few pounds per door, and it "does" make a difference in my experience.

Another tip is to buy a roll of A/C Duct wrap made by Frost King, it's more of a sound barrier, and also reducing road noise in another way and keeps the car better insulated from heat and the cold. It does it by the foam cells in the wrap. The asphalt based products reduce noise by adding weight to metal and reducing the sound waves and vibration from passing through the sheetmetal. While the foam wrap works as an absorber of sound, not as a deadener like rubberized asphalt. So they work differently, but harmoniously.

Using both will give the absolute best results from a NVH standpoint.

Here's some links to the products I mentioned. There's another product which I haven't used, but looks to be pretty good and is highly rated which is called DB-3 it's an acoustical barrier.



1964 Sedan Deville (Own)
1987 Brougham D’Elegance (Sold)
1954 Cadillac Fleetwood 60 Special
1994 Fleetwood Bro (Sold)
1972 Sedan Deville (Sold)
1968 Coupe Deville (Sold)
1978 Lincoln Continental (Own)
1979 Lincoln Mark V Cartier (Own)

Chuck Swanson

I did notice on the second link, http://www.homedepot.com/p/Unbranded-4-ft-x-8-ft-Acoustical-Barrier-DB348X96BX/100663624  a comment from the manufacturer in the Q&A:

"dB Sound Control
July 9, 2015
The material is composed of EVA, not PVC as such there is no plasticizer to give off that familiar "plastic" smell.
Although it may be used in a car, we do not recommend it, maintaining proper adhesion to the surfaces will pose an issue during install. The adhesives required will have a distinct odor that you are trying to avoid.
Thank you! "
CLC Lifetime
AACA Lifetime
Like 65-66 Club: www.facebook.com/6566Cadillac
66 DeVille Convertible-CLC Sr Wreath, (AACA 1st Jr 2021, Senior 2022, 1st GN 2022)
64 Series 62 (2)
64 2 door Sold
66 Sedan DeVille hdtp
66 Calais pillar sedan
66 Series 75 9-pass limo
65 Eldorado (vert w/bucket seats)
65 Eldorado Bk/Bk Sold
07 DTS w/ Performance pkg.
67 Chevy II Nova (AACA Sr GN 2018)
69 Dodge Coronet R/

gary griffin

I was planning on using a product I used in my business. It has a vinyl side and the rest is foam rubber with embedded lead particles. We use it to deaden the sound from noisy sheet metal and fans. I am retired but still have a lot of remnants so I went to my storage and got a roll big enough to do a car. I its heavier per square foot than any of the other products. The problem is that it is that my remnant is over 30 years old and the foam was falling apart. Instead  used a product called "Rattle trap" Made by one of the others but even better adhesion and 80 mils instead of 50 mils. Not cheap but what the Heck, it is a Cadillac.
Gary Griffin

1940 LaSalle 5029 4 door convertible sedan
1942 Cadillac 6719 restoration almost complete?
1957 Cadillac 60-special (Needs a little TLC)
2013 Cadillac XTS daily driver

David Greenburg

No personal experience with the asphalt products, but during my research on sound deadening products for my car, I came across a lot of complaints  about the smell of some of the products from people installing it in their cars.
David Greenburg
'60 Eldorado Seville
'61 Fleetwood Sixty Special


"Rattle Trap", as mentioned by Gary Griffin is an excellent (maybe superior) substitute for Dynamat and others.  I used it throughout my '35 Cadillac including the underside of the roof and the same with the Mark V Jaguar I am doing now.  Rattle Trap does not advertise like Dynamat and does not have "celebrity" automobile people endorsing it, so, if for no other reason, it is less expensive and performs at least as well.  Readily available on eBay Motors. 
1935 Cadillac Sedan resto-mod "Big Red"
1973 Cadillac Caribou - Sold - but still in the family
1950 Jaguar Mark V Saloon resto-mod - Sold
1942 Cadillac 6269 - Sold
1968 Pontiac Bonneville Convertible
1935 Glenn Pray - Auburn Boattail Speedster, Gen. 2

Art Gardner CLC 23021

I have used "FatMat" brand of insulation on a few old Cadillacs and have been well pleased with the combination of price and performance. 
Art Gardner

1955 S60 Fleetwood sedan (now under resto)
1955 S62 Coupe (future show car? 2/3 done)
1949 S60 Fleetwood sedan (restored 30+ yrs ago)
1958 Eldo Seville (2/3 done)