Hey folks,

I spent some time looking through old threads concerning sound deading and the like. I still have a few questions. The interior is down to bare metal now. What specifically was the purpose of the tar pad? Just sound deadening? What about the pad on the engine side of the firewall? Sound and heat, or just sound? Here's what I THINK I'm planning on for the interior. Let me know what you guys think. First, I will paint body color. Then, I am planning on the Herculiner stuff. I know it's not stock, but I think it will work for my purposes. I understand that it has some sound deadening qualities, but not quite enough. So, I am also thinking about getting the FatMat stuff on top. Then, on to carpet. As for the engine side of the firewall, should I just use more FatMat, the old pad, or something else. As you can see, I am open to suggestions. I am not concerned about keeping necessarily stock as it will be covered with carpet anyway. I just want to be comfortable in my car, and be able to speak to somebody while I'm in it. Suggestions, comments, alternatives are welcome.

Thanks. Sorry, it's kind of long.

Alan

If you want my opinion the more layers you are putting down, the better are the chances of water getting trapped. Alot of people here like to coat the metal prior to paint with some POR15 a epoxy based paint. I am not familiar with FatMat and Herculiner, I know though that most bodyshop suppliers will sell some sound deadening material that is very close to the original material,it is tar based also and comes in packs of six square foot sheets. To do the floor on the car you neet two packs.

The engine bay pad is also a good water trap, I think Dynamat makes some special covering that is also fire resistant.

In the end it all comes down to what you can find locally and how much you want to spend. Hope this helps.

From bare metal, add POR15 or a similar rust preventative coating. Then apply your sound proofing. I used QuietCar, which is a roll-on/brush-on type deal. You can get a gallon for $50 or so and it is enough for multiple coats of the floors, sides, back panel, etc. Says it doesn't retain water and can be applied over POR (do a google). Then stick in your carpet and padding if you need. I agree with Mihai that any layers you put in add to the chances of moisture.

Oh, why would you paint the metal first? It's just going to get covered up. The factory applied the sound deadener and then painted it.

Mike (in Portland)

The spray on "bed liners" installers say it should go over paint, don't know why.

I know that others have put this in and on the bottem of their cars, I am doing the

same. Dyna mat on the inside vertical surfaces Is also a good idea and has been

done. But it is a fact of life, 914's get wet inside. I for one would not put it on the

floors. IMHO

Click to view attachment


Hi

I have done all of the above, bare metal, metal ready, Por15, Por etching compound, and I used a bedliner that can and was tinted to the color of the car.
The stuff I used does not suck up water, and works well for sound deadning.
This was one of those projects that the costs were a lot more then expected, because their "quantity needed" was about 1/4 what it actually took.
I used a special gun for the application (shop tool) not a shultz gun. Most people and myself included do not like the ruff look when using a shultz, but it is often the only option.

Later

73 - 2.0

I stripped to bare metal, repaired all the rust, dressed all the welds, Metal Prep, inside and out...Then covered the underside with POR15 and then Herculiner...So now the entire underside (fenderwells included) are Herculiner...It is Polyurethane based so it can be painted...Brush on 2 coats and I think it looks great...

Inside floor and trunk area under the tailight housings is 2 coats of POR15, Scuff with sandpaper or Scotchbrite, paint for final rust protection...

I have not decided what exactly I will do on the firewall...Except that the old pad went directly to the trash can and I will never put anything that will absorb and hold water against the firewall again...But the last restoration I did, I painted the firewall and left it uncovered on the engine bay side...Looks great but boy was it noisy...My initial tought is Dynamat as it does not absorb water...That will hold down the noise and heat from the cockpit...

Inside both doors will be Dynamat and the floor at a minimum will be 7/16 carpet pad...I sew my own carpet in...If you take this approach, you MUST MAKE CERTAIN, you have no water leaks from the windows, doors, etc. or you just start the rust cycle all over again, and very quick...

The main problem with Dynamat and similar products is the weight...

2-OH!

Whatever you use, don't get it on your hootus

Just my .02, but why notjust use a good primer, and the por15 on the floor? You can do the same thing and then add the fatmat on the firewall. I don't think you would really gain anything by using it on the floor.. As others said, these cars do get water in them,and when you add additional material that will only retain water, your just asking for future problems....

Good Luck..

por15 and fatmat would be a good choice. Fatmat is a great product and alot cheaper then dynamat.