Insulation sound deadener

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Iowa
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1973 Mustang Grande 351C 2v
See pics below. I'm going to be installing new carpet. Cut pile with mass back. My original floor insulation is in decent shape. Is it worth my time to pull it and replace with dynamat or rammat or equivalent or should I just leave the original?


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I would at least pull the carpets and the sound deadener too have a look what the conditions of your floor pans are. One mine after pulling the carpet it looks exactly like yours. But after pulling the original sound deadener in the front feet room both of passenger and driver site I detected some spots with minor rust film. The original paint coat in the interior is very thin so it is easy for minor rust film to come in. I will take away the original sound deadener and use them as a pattern for a more modern equivalent. I will then brush the rust film away and give it all a new coating.

So you better have a look underneath. If all seems okay I would let the whole thing as is and cover it with the carpet as before. If not - you could proof my suggestions... ;)

 
+1 with 'timachone'. I would add that if it's in the budget, replacing the original with front to back new modern style sound deadener will result in a much quieter ride.

 
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If you replace it with the same type of product you might want to stay away from the stuff made by custom auto carpet. I just bought from them and it was rolled up in a box. When I unrolled it ,it was so bridle it broke apart. They wouldn't even answer my email when I contacted their customer service. I should have went with boom mat or something like that. But wanted to stay original like the manufacture used.

 
I don't know, maybe its just me, but if I pull the original carpet today I am certainly going to renew the sound deadening material underneath. I just worry about the built up moisture waiting to seep into the crevices + the fact that the intended properties of the original material have far surpassed their useful life. For the cost of replacement, it is a safe bet to renew this type of material.

 
For a few bucks more, if you're replacing a 40+ year old carpet, do the same for the underlayment. It may look good, but it may also harbor some mold and moisture along with odors of the past.. JMHO

 
I've put in Dynamat, and unless you cover every square inch of metal, I can tell you that my experience is that except for inside the doors, it really did not make much of a difference in sound control. Looking at your pictures, I would say if the underlayment isn't brittle and breaking into pieces as you handle it, I'd simply leave it as is.

One place I believe the mat would be great is on the roof panel, if you had the headliner out.

There is merit to pulling it and replacing it, I suppose, but I don't see a reason in this instance, unless, like I said it is brittle or seems to have moisture soaked into it (Which seems very unlikely to me, given the condition of your floors)

 
Thanks for the advice. I am going to pull it as it is pretty brittle in most spots. Only a few areas you can move it without breaking. It is dry, no signs of moisture, just most of it is pretty brittle, so I don't think it is doing anything. I picked up some sound deadener from a buddy of mine who does stereo installs today. He said it is slightly better than Dynamat but only comes in 9" or 4" wide rolls. He sold it to me at his cost so I only have $80 in the whole deal and he gave me what looks like enough to cover a very large SUV. We will see how it goes. He said to use an ammonia based cleaner before installing to get the best adhesion. Does this sound right? Windex?? He did also mention to get the seams as tight as possible and gave me a roll of foil tape and said to tape the seams once installed.

 
I did the Raamat under the jute-backed molded ACC cut-pile carpet in mine. I had to replace floor pans, and didn't really care for the OE "loop-style" carpet, which is why I went with the cut-pile.

The Raamat (Dynamat, et al) is pretty easy to install. Just peel, align, stick it down, and use a wall-paper seam roller to mash it flat. Not only does it help with the sound resonance, it's also a thermal shield.

Doing the roof made a huge difference, as Jeff mentioned - it went from a very tinny, resonating 'throng' with you tapped on the roof, to a much quieter dull 'thud' after applying the Raamat to the inside of the roof before re-installing the headliner. I anticipate it'll help reflect some of the heat from the West Texas sun as well.

I used 3 35 sq. ft. kits to do mine - floor, firewall, roof, doors, quarters, and trunk. The good thing is that it's significantly cheaper than Dynamat (probably 25-30% cheaper, as a matter of fact).

Hope that helps.

 
OK well that confirms he gave me way to much. I was only doing floors and what ever I can cover with the carpet and seats out. He gave me 120 sf. I don't want to pull the headliner as it is in perfect condition and as I understand not that easy to reinstall.

 
Sounds right to me. Most of that stuff rolls down to conform to the floor shape really well. There are rollers for installing it, but you can also make your own out of all sorts of items. I found a nice wooden spoon in the kitchen that worked well and you can use the small end of the handle to press into the ribbing of the floor pan. Gaps in coverage do decrease the effectiveness, but are inevitable inside the doors and quarter panels if you even try to apply it there.

 
Some of the professional installers use 'strips' for the inside of the quarters and door skins - basically, it's there to disrupt the resonance. I skinned the entire floor, firewall, roof, and trunk for heat shield benefits as well. Strips are inside of the door skins and quarters, with some of the deadening foam sheet inside the doors and quarters in-place of the water shields.

It's pretty quiet in mine all things considered, although I haven't driven it with the windows up, yet.

 
Some of the professional installers use 'strips' for the inside of the quarters and door skins - basically, it's there to disrupt the resonance. I skinned the entire floor, firewall, roof, and trunk for heat shield benefits as well. Strips are inside of the door skins and quarters, with some of the deadening foam sheet inside the doors and quarters in-place of the water shields.

It's pretty quiet in mine all things considered, although I haven't driven it with the windows up, yet.
What did you use to clean it then? denatured alcohol would not leave a residue and shouldn't harm the paint. Otherwise I was going to use ammonia and water to clean then dry with air compressor and fans but would rather avoid using water if possible.

 
I use 3 layers of Lowes peal and seal on all floors and trunk, all Dynamat on the roof, doors and side areas. I have about $300.00 into sound deadening but the stereo sounds great along with no interior noise or rattles, well worth it in my opinion.

 
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What did you use to clean it then? denatured alcohol would not leave a residue and shouldn't harm the paint. Otherwise I was going to use ammonia and water to clean then dry with air compressor and fans but would rather avoid using water if possible.
I had to replace the floor pans, and pretty much every surface inside my car had rust in some form or fashion. Once I removed the rust, welded in the new sheet metal, and got everything else ready to go, I used some Xylol Xylene ( http://www.amazon.com/Klean-Strip-QXY24-Xylol-Xylene-1-Quart/dp/B000V4L86A ) to wipe down everything. Once it "dried," I painted everything with Rust Bullet Black Shell. After that was all dried up, just a quick wipe-down with some House of Kolors KC10 Wax & Grease remover ( http://www.amazon.com/Gallon-GREASE-REMOVER-KC-10-HOUSE/dp/B001KN1JQ0 ). Then the Raamat.

Here is it going in:

RAAMat1.jpg

And here it is pretty much done (after the firewall pad and Classic Auto Air HAVC unit installed):

HVAC1.jpg

 
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