steverw

Hey guys has anyone used Fatmat, Dynamat, or any kind of sound deadner in the doors and rear quarter window area? If so does it help much? Just trying to decide if i should while my windows are out. I have some Fatmat left over, but i dont want to cause any possible problems of trapping water in the doors.
Any opinions on this?
Thanks
Steve

Allan R

I haven't done this, but would like to one day. I've read through numerous posts where any of those products was used inside the doors. It apparently does cut down quite a bit on the sound and insulates against heat too. As long as you keep the drain holes at the bottom of the door open you shouldn't have any issues other than what's normal. Most of the posts suggest that you don't do the whole door, just the middle section from about 5" below the drip edge to 5" above the bottom pinchweld.

Far as I know it doesn't interfere with normal window operation either. The other think that has been commented on, it gives the door a more solid sound when closing.

Post pics of what you end up choosing.

steverw

Thanks Allan that sounds easy enough, i think i just might do this.
Steve

oldcutlass

I won't use that tar type crap in any car I own. I spent a week trying to remove it from a car I am modifying for an engine and trans swap that required cutting and welding on a trans hump, firewall, and floor. Its a bitch to remove.

On a side note, another friend used the home grade stuff bought at Home Depot in his door panels and floor and wound up with a goopy mess due to the Texas heat.

gbledsoe3

Check out this post I recently read on the Pro-Touring forum. I'm not to that point on my project so I bookmarked it for future reference. I'm not saying I'm going to do that but will research more when the time comes.

Sound Deadening

cdrod

Steve:
The Dynamat stuff is a hugh improvement. I did my 4Runner several years ago when I replaced the factory radio and blown-out speakers. I did all 4 doors, floors and the parts of the rear cargo area. Easily cut the road noise in half and significantly tightened-up the bass from my door speakers. Most people apply the peel and stick stuff to the interior side of the doors, so I sprayed rubberized undercoating inside the door on the outer skin. But as Oldcutlass pointed out, it's messy s%^! to remove, once you've stuck it down it's not coming back up!
There is a less expensive peel and stick product called B-quiet that is only sold on-line, direct from the manufacturer. It's comparable to Dynamat but about $2.70/SF where Dynamat is about $3.90/SF. A lot of the resto-mod restorers are now using a spray on product called Lizardskin because it's easier to apply and get into tight spaces. They make a sound control product and an insulation product. It's about the same cost as Dynamat if you apply both products. I am planning to use Lizardskin on my convertible project. HTH.
Rodney

pcard

I used Dynamat in my doors and quarters. I would highly recommend it. Quiet ride and makes closing the door sound like a mercedes.

Firewalker

I used Peel and Seal a number of years back, which can be found at hardware stores, for roofs.


It can be had in smaller sizes and I liked the 6 inch rolls I bought and used. The stuff is cheap and beastly good. It smells a little like tar at first, but the oder goes away in days, to a few weeks. Many have used it in their cars.

harwooddan

I used dynamat in my 55' Super 88. I only did the trunk floor and interior floors. The car does not seem any quieter but there is less heat from the floor.

Firewalker

If striking the metal, with say a wrench or wooden handle, does not produce tin can or trash can sound, then they will have little effect. Think of the cab of 1960s and before pickups.

Or if things are lose and vibrating...and you see this a lot with bad stereo installs, then it will help if placed right. The mat is design to stop or greatly limit flexing vibrations in the metal. Heavy thick metal of old is different than thin sheets of metal and already resists vibrations/flexing.

cfair

The best fix I've done in years was to put Trim Lok flap seal (1.75" flap with a U channel for 1/4") on the upward facing rims on the outside of the top frame.

You can get it on Amazon here:
I'm awaiting delivery on the 3" flap seal version which I suspect will lie better on top of the outer edge of the top pads, but this was a big step forward at least for me.

I also like Dynamat for reducing road noise. I have it in both cars and have insulated my doors and quarters with closed cell foam too.

Chris

70cutty

I've used peel and seal from Lowes in my Impala and FatMat in the Cutlass. there is a big difference between the 2. Peel and seal does works, but nowhere near as good as 80mil fat mat. The difference in road noise and heat coming in the cabin is noticeable between the 2.

Firewalker

There were areas where I did more than one layer of the peal and seal, where I thought it might be needed. And not all areas seem to need this. My main aim was less about heat, and more to kill the echo effect, of a hollow tin can and make it quieter.

pcard

Hey Cfair do you have a photo of your installation?

cfair

If you mean flap seal installation on the convertible top, look here:
https://classicoldsmobile.com/forums...op-tip-140154/

I don't have photos of the dynamat install, but in both cars I did 100% coverage from trunk to firewall for road noise and a little bit of the doors of one. Dynamat sticks to the cleaned up metal in place of the old tar stuff. Mainly you want to route it _under_ and wires, wiring harnesses and vacuum lines which run stem too stern since the stuff won't come up again easily. Or cleanly.

I even stuck dynamat on the underside of the Starfire hardtop roof panel. I think it helped there too. No problems with unsticking after 2 years, but I'm in the Bay Area where we don't very much extreme weather. Cleaning off the original cardboard/breadboard stuff was a pain and very messy - chemicals, scraping & lots of cleaning. It took a couple of days to get it really clean to promote maximum adhesion of the dynamat.

It's in the back of my mind to do the door skins maybe 25% coverage, but then I'd have to consider the fenders and rear quarters too. I haven't gotten around to that yet.

As noted I'm still working on the doors, my current solution is 1/8" and/or 1/4" thick closed cell foam in place of the old tarpaper water seals behind the door panels. I'm adding a few additional P seals and other seals in the door-to-body voids over time to see if that makes a difference too. The jury is out on those trimlok seals, but I'm happy with it so far.

I'm not sure I needed complete dynamat coverage of the floor, the downsides are cost and weight. But then how light are 66 big cars anyway? I don't seem to have affected MPG much.

What you learn is that once the big noises are gone, the little noises come out and you may start chasing them.

cheers
Chris

Firewalker

To add maybe to this subject, the tin can sound is what you are trying to really kill with the sound deadeners, so the tin doesn't not resonate like a bell from other sounds. You are trying to shift the ringing from a high pitched sound to a much lower pitched sound. Hit thin tin lightly, with an open end wrench and you get a clang sound, but this ring frequency changes with sound deadeners stuck to them, and you will hear more of a clunk than a clang.

If I want to silence something I tap with a light piece of metal like a wrench, to check the frequency, by taping in various places on it, and if a clang then it needs the sound deadening, and its not needed everywhere. On my doors for example, I did not cover them for example in sound deadener, but just put it in certain places where the metal clanged when tapped.

One layer gets you one change in tone hitting that bate metal area, but two layers will lower it a little more, if it still sounds a little ringy to your ears.