anyone done the dynamat thing?

[bravohotel]

My newly acquired '72 2.0 is setup to be an auto=x machine w/ a semi-bare interior and almost zero undercoating. As a result, is kind of loud on the road. I would like to use the Dynamat stuff to see if I can quiet it down a bit. Anyone used this stuff? How heavy is it? The only thing that kind of bothers me is the "permanent" adhesive. I want to be able to pull it up at some point in the future to look for new rust, etc. How hard is it to remove? Any help appreciated. Thanks

BH

[Brad Roberts]

The Dynomat works great. Its a little pricey for the area your talking about covering. If I where you..I would look for a cheaper alternative to actually using Dynomat.

As far as it coming up later.. it cant be any harder than the OEM tar paper is to get up.

Most people I know with NO tar paper just run a second set of floormats.. or second carpet lair.

B

[hardflex]

I've done something similar to my 72, but I can't vouch for it's effectiveness since I haven't had it on the road yet, close though.

I used an Ebay alternative and it went on great. I'll post some pics tomorrow. I've put it behind the seats and I'm going to drop the motor and do it to the engine side of the firewall too.

I even considered doing the bottom of the car, but I wasn't sure if it would keep moisture out or trap it in. What do you think, Brad?

I was in a roofing supply store and they had something that looked suspiciously like it there. I didn't ask for a price, but you might inquire there.

PD

[Brad Roberts]

Be careful in the engine compartment. The heat will make it fall off....and guess where it ends up ?? I have several "friends" that have muli-layers of the knock-off stuff on the inside of the firewall behind the backpad. Works very well.

I dont think you could make the stuff stick under the car... Not because it wouldnt... but because you couldnt get the car clean enough unless you blasted the hole bottom side.


Nah.. Texas heat would cause it to fall off..LOL

B

[pbanders]

I used Dynamat in my doors, it definitely reduces noise when you have the roof in and windows rolled up - which I just about never do. Secondary benefit is that the doors don't sound quite so much like a Yugo door when you close them

[mike mueller]

For the interior, I used roofing tar paper, 5 bucks for a 10 or 20 foot roll of it.
It's got an adhesive backing and I used a hairdryer to form it on the wall and floors.

Much cheaper than Dynamat !!!!!

[maf 914]

I put Dynamat on my doors also. I used it to replace the clear plastic used as a vapor barrier between the upholstered door panel and the sheet metal. It did give the doors a more solid sound when closing, but while driving wind noise from the window seals overrides any noise reduction it may have made. I also placed it behind the speaker boxes in the kick panel area.

Try a search in this forum for sound absorbtion or Dynamat. This was discussed several times in the past. There are some similar cheaper products available from places like McMaster-Carr industrial supplies.

Mike

[korijo]

After removing the German Elk Buckskin material, AKA engine insulation pad, I dont think I want anything else on there. That $h!+ is putrid. Bare is the way to go, IMHO

[J P Stein]

Jeeze, I just posted this pic.....a rerun. Aluminum backed Dynamat on the firewall. It's been there for a few years and is hanging in there. I have taken off a few small areas...it don't come off willingly.

It cut the DBs in the pilothouse to under 100, I think

[douglas robbins]

Mike's roofing tar paper idea is interesting. Is there any argument for not using this stuff on my bare floorboards as compared to using (1) dynamat or (2) using some other cheaper asphalt adhesive auto product.

I'm intregued by the tar paper idea because it seems like a very intexpensive but effective way to go.

Anybody want to challenge Mike's wisdom? Otherwise, I'm going to the hardware store.

[bowlsby]

'Tar Paper' is uh...paper...think organic...think water absorption....and it does not bend easily.

I know its asphalt saturated...but it will soak up the H2O if allowed.

I *think* Mike was referring to self-adhesive membranes...Bituthene and similar products...they are 'self-adhesive' where paper would not be, and they have a polyethylene facer. Very sticky.

Self-adhering membranes may be available at Home Depot, but your best bet is roofing supply houses...Ask for Bituthene 4000, Ice and Watershield, Polyken, Jiffy Seal...

Its used for waterproofing purposes.

[mike mueller]

Jeff is correct....I didn't use "tar paper" as in the fiberous type...my bad

The material I used had a plastic backing which had the adhesive on it.

[norustscott]

I am with JP...Dynomat in the engine compartment...it is not going to fall off. I pitty the guy who wants to take it off... I have the stock rubber mat (minus the fiber backing) over the Dynomat. looks stock very quiet and less heat in the cabin.

[jabb]

JP ..... You still recycling old pictures..... where the MSD ???

[never_2nd]

I haven't used Dyanamat in my 914 yet but I did use it in my Monte Carlo I restored. I used it all over the floorpan, interior roof and inside the door skins. It has worked great for over 3 years. I found one really neat trick. If you cut the large sheet into 2 inch squares and place them like a checker board, with uncovered space between the Dynamat squares, you can cover alot more area and it seems to provide as good a sound dampening as the entire sheet. I also prepped my sheetmetal with prep-sol and isopropyl alcohol prior to placing the Dynamat. Hope that helps

milt mcpherson

[red-beard]

Carr-MCMaster sells a dynamat like substance for much less than the offcial Dynamat. They also sell sound deadening paint, which you could use in the wheel wells and places it would be hard to put the Dynamat.

http://www.mcmaster.com/

The Stuff is heavy. My floor pan had been replace with no sound deadening. I pulled up the seats and the floor mats plus did the firewall and the front trunk. It has made a big difference. Less road noise - but I can hear the 6 better!

I've been looking into how to reduce the engine noise into the cabin. With the intakes of the 6 right in front of the window, you have little chance of reducing that noise. However, I have found a sound absorbing mat which I think could be hung under the Engine lid, which would help on noise, without restricting air flow into the engine.

"Water-Resistant Sound Absorbing Sheets - Made of bound polypropylene beads, these rigid, flat sheets will not degrade when splashed with water or saltwater. Often used as a liner in moist environments such as marine air inlets. You can cut sheets with a razor knife and mount with a rubber-based adhesive such as 67015A on page 3134. Temperature range is 0° to 240° F. Color is gray. "

[ss6]

I've seen some guys with track cars who've used that "feet saver" cushion runner custom cut to fit like two large floormats. This stuff is used in front of machines or tables where people have to stand for long periods of time. You can get it through Global, McMaster-Carr, etc, and some sports places sell the stuff as "exercise mat" for weight lifters. The stuff I saw was flat black, and about 1/2" thick.

The good news is it's waterproof, dampens floorpan vibrations, and you can pull it out like a floormat when you want to go supersonic. The bad news is its kinda heavy, but no heavier than the stock (interior) backpad.

[J P Stein]

Joe:

OK, we're even.
Pop on over on the 28th and you can see it for yourself.

[kellzey]

red-beard...

The product you described says "rigid".

Wouldn't you want something flexible to conform better to the recesses in the floorpan or the firewall.

I think I've seen this type of material before. It's a porous hard sheet of sphagetti-like material. I think it acts more like an accoustic baffle than a sound deading material like dynamat.

Like you said... it would probably work "under the engine lid".

Happy Holidays...