I'm in the middle of doing the sound deadening material and insulation material on my 78. I've seen a lot of videos about doing this and what products they are using. I've already picked my products so that's not im interested in. I want to know if anyone has done sound deadening and insulation on the B pillar plastic panels. Any pictures?

 

I guess they call them rear roof panels coupe. I'm wondering if anyone has insulated them.

 

So I'm going through a similar interior redo on my 70 coupe. At least on mine there was only sound deadening horizontal to the floor basically, and along the rear wheel wells. Maybe they changed approach in later years, but seems most of the heat would be from the bottom, not the sides. As for sound deadening right along side the window, seems it would be a negligible net effect to me, with the window seal potentially being the primary source of noise. I guess if one had sidepipes, it might help there... perhaps someone in forums has experience there.

 

ClassicJoe,
Thanks for your input, every little bit helps. I had a lot of noise when I first decided to do sound deadening and heat insulation. When taking things apart to get to the point I can take out the carpet, I started noticing things like the rear speaker mounts (factory) were real loose and rattling. The security curtain bolts holding it in were real loose and would make a lot of noise. (1978). There was zero factory sound deadening or insulation in the luggage area behind the seats, looks like someone had taken it all out. Also I found that one of the mufflers was touching the tire carrier and transferring sound right under the luggage compartment where there was nothing stopping it. I plan on putting sound deadening and insulation everywhere which might be overkill but I don't care at this point. I'm betting the car will feel much better and provide a nicer ride experience than it did before my fixes. I was just wondering if anyone put sound deadening or insulation behind the plastic b pilller interior panels. Mine had almost nothing on them but there was something there from the factory.

 

I added sound deadening and heat insulation to the roof cross-over and inside the T-tops on my 78’s. Unfortunately, no pics. The T-tops had a surprise construction detail. Velcro tabs holding the interior lining on had contact cement added to make them hold. About half of the tabs pulled loose from the paperboard lining. It wasn’t too hard to pry the glued Velcro apart, scrape off the glue, then glue them back onto the paper board with contact cement. Tried having them stay in place with only the Velcro interlock, but the ceiling came down on my head while driving LOL. Resorted to using more contact cement between the Velcro tabs. It’s been a few years since and no problem. Used Dynamat in smaller pieces just to dampen sound vibration of the roof metal; didn’t want to make the T-tops much heavier. Added a full layer of Reflectix for heat insulation. Along with a good windshield cover it takes awhile for the interior to heat up when parked in the sun.
Charlie

 

Look closely at the space between the plastic interior panels and the body.
There isn’t much space between the two and I’m not sure if there would be any open space to put in any type of sound deadening material and still get the plastic panels to fit correctly.
I used Thermo Tech heat shield in my transmission tunnel and it’s pretty thin, but even that might be too thick.

 

It's always good to get advice from someone who's been there and done that. Thanks for all of that. and I figured that the Velcro tabs might pull off but I'm going for it anyway.

 

OldCarBum,
Good advise. I'll use some putty on it and install then see how much room I have to work with. There has to be some because there was originally some of that cruddy fiber straw stuff in there, but not much at all. I'll let everyone know what I come up with.

 

On my 73 there was no factory sound deadening material sprayed above the floor, part way up the transmission tunnel and nothing in the rear above the tops of the interior wheel wells.

 

Wow, it sure is disappointing that GM skimped so much on things that would have made their cars drive like it's better built. One other question. When I ordered my materials, I also ordered some tape. I just ran out of it and I'm wondering if I can just buy some aluminum tape like they use on heating ducts or if the tape for our cars is different?

 

Assuming you are using Dynamat or something similar, yes, I just used aluminum tape I picked up at the hardware store. I did mine a little at a time and the best results were after I did the doors. I didn't do the whole door, just parts of it, but it made a huge difference in noise.

 

Yes my doors are very noisy as were other c3 Vettes I've been in. I want to do them with sound deadening but also need to replace the window felt and rubber because they are mostly gone.

 

I picked up an extra roll of aluminum tape from Ace Hardware.
It was actually rated at a higher heat threshold (only by 15 degrees) than the tape I got from Thermo Tech.
I got about twice the amount on the roll compared to the Thermo Tech brand which made it half the cost.

 

Do you have any pictures of the areas you applied the sound deadener to the doors?
Did it cause you any issues when you installed your interior door panels?
Thanks!

 

One of these pics shows a little of the dynamat applied to the doors. I had all of the guts out of the doors to service the window mechanisms. Smaller pieces, about 2x5” applied to dampen the sound vibration of metal panels. Areas determined by accessibility and non-interference with moving parts. Dynamat is fairly heavy and I was concerned about causing extra wear on the hinges. Adding a few extra foam blocks to the opening/lock rods and zip locks to the metal-on-metal connections worked very well to quiet the rattles in the doors. Did need to add a few more as additional rattles heard on test drive. So, don’t put the door skins back on till you’re happy with the results. To the OP, when replacing the felts touching the glass, be extra careful about the outer window felt. A new one there will be thicker and push the window inward. That turned out to be the most difficult glass adjustment to correct. Be very careful with the original, it might need to be reused if a new one is only slightly different.
charlie




Just for the fun of it!

 

Thanks for another good tip. When I get new felt for my windows I won't just slam the door thinking everything is finished. I'll keep in mind to look at the fit and adjustment before considering the job done.

 

So I took some aluminum foil from the kitchen lightly crumpled it up and put it between the b pillar and the molding. It looks like about 1/4 to 3/8 of an inch space so I'll be putting a little insulation in there. There is no need to put sound deadening there because they are wrapped in vinyl or leather and they sound solid.

 

Sound deadening and insulation is in and carpet and seats are back in. Just waiting on the battery to charge so I can take it out for a test drive with the dB meter. More to come.