Thread: Cork as sound deadener? Recommend other materials to absorb noise.

Hmmm, seems you're trying to eliminate "sound" in the car by insulation.

Most road noise is the resonance of the vehicles metal panels. Aftermarket stuff bonds to the metal for a reason. It adds mass. This helps to keep the panel from resonating. They also have other qualities that help eliminate sound, mostly "coverting" the sound energy into a different form of energy (essentially, dampening).

By just laying foam (underlay) on the floor you've helped some, but by using the wrong mechanism.

It's doubtfull if bonding the material to the car will help much more either. You really have to add mass to the panels.

I'm not saying all your efforts are for naught, just that they aren't going to as be effective as the proper materials (as you've found out already).

But your car is probably well insulated for winter

Cheers

put the foam in your ears that will work lol. Seriously tho as greatwhite says really and the cork is to dampen reflected sound which is not what your problem is. Vibration is sound that's why Dynamat works by stopping it.

concrete?

Thats a good point about the mass loading to kill vibrations. That's why I have a layer of Resisto stuck onto the metal as the mass barrier, then I have another layer of carpet underlay foam as a sound barrier (which its not very good at).

I saw an informative thread on the civicforums about using "jute." It looks like the stuff that is used as a stock sound absorber in most vehicles:

http://www.civicforums.com/forums/21...ening-diy.html

Seems to be a promising material. Maybe I'll see if I can get it cheap somewhere.

Jute is ust the stuff stuck to the back of factory carpets.

Not that effective, but it is heavy.

God help you if it gets wet.................

I worked at an AC shop, and they used this stuff (we called gumbo), but it's basically a type of plumbers tape, made from cork and tar and maybe rubber...
I've used that to line the panels in my car, and laid 1/2" black, closed-cell foam rubber on top of that (also from the AC shop), and the difference is amazing...especially in the doors.
I've done the trunk, rear quarters, doors, B and C pillars...
I'll be doing the front wheel wells and the bottom door sills this season...

If Dynamat seems a bit expensive, you can check out some of the generic Sound and Vibration Damping Sheets at McMaster Carr. Search for catalog pg 3427. Some of them are along the lines of original Dynamat (DLF = 0.08 at room temperature). I used some a few years ago and I THINK it was 9709T39, but I can't remember for sure.

I use spray on truck bed liner. Works great and you can put it on thick. It is a little bit expensive. For 100 bucks you get like a gallon.

... tends to stink. That is the thick chopped cork tiles; I think the sheet stuff might be too thin to do you any good.