Sound Deadener, how much and a thought...

[Malicious]

Hey Guys,

I'm about to order in some sound deadener for my 68 Coronet, couple of questions.

How much square feet will i need to do the whole cabin? firewall to parcel tray? I'm not going to do the boot yet, but I will do the roof.

Also, a thought, I was going to run a Butyn (dynamat) like deadener, but I was thinking would it be better to run a foil backed dense foam (like the dynalite) on the roof and C pillars? Thought being that the extra weight up high might unbalance the car? Raise the centre of balance a bit yadda. Don't know how much the Butyn matting weighs exactly but I've heard its pretty heavy, enough to make a difference?

Thanks in advance!

 

[Propwash]

50-75 SQ FT.........

Did the floors, roof, front of the wheelhouses, inside of the doors, inside the rear interior panels......Used about 75 SQ FT

 

[440+6]

I just did my GTX, I used Fat mat's rattle trap product 100 sq ft and did from firewall to package tray and doors with about 20-25 sq ft left over.
I did not do the roof but I think what I have left should be close but not quite enough, they do sell 25 or 50 sq ft rolls also and I think other vendors will also.
Hope this helps.

 

[tallhair]

I just did my GTX, I used Fat mat's rattle trap product 100 sq ft and did from firewall to package tray and doors with about 20-25 sq ft left over.
I did not do the roof but I think what I have left should be close but not quite enough, they do sell 25 or 50 sq ft rolls also and I think other vendors will also.
Hope this helps.

View attachment 103293

you are the first one i've seen do the inner door panel area instead of putting it on the inside of the outer door skin ... i'm interested in the effects on putting the door panels on/fit finish etc. anyone else done this?

 

[Malicious]

Hmmm, the Butyl deadener I was looking at comes in a pack of 64 sq ft.... might need some more.

440+6 the rattletrap is supposed to be a viscoelastic foam, how did you find it? light? good quality? Cut down the sound much?

Thanks for the replys guys!

 

[rev.ronnie]

I did the floor of my Charger in Dynamat. My thinking is that probably 80% of the heat is controlled by then floor, and firewall. I was right, that car is real nice to drive in the summer, while my stock 70 roadrunner was undrivable in the same weather...it was a sweat lodge.

We did not do the doors or roof. What is the overall thought on what that does over and above just the floor/firewall?

 

[440+6]

you are the first one i've seen do the inner door panel area instead of putting it on the inside of the outer door skin ... i'm interested in the effects on putting the door panels on/fit finish etc. anyone else done this?

All four panels fit perfectly although I think inside the door would probably be a better job overall.

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Hmmm, the Butyl deadener I was looking at comes in a pack of 64 sq ft.... might need some more.

440+6 the rattletrap is supposed to be a viscoelastic foam, how did you find it? light? good quality? Cut down the sound much?

Thanks for the replys guys!

The rattle trap is a "viscoelastic damping compound on an aluminum foil" (whatever that means) seems like butyl but it's not, feels more like a soft rubber compound.
I didn't drive much because its mid winter here (freezing and salty roads) but it did cut down on sound quite a bit. I'll have to wait for summer to find out how much it cuts down on the heat.
It was very easy to put down and 100 sq ft = 43 pounds shipping weight.

 

[Malicious]

Yup the visco elastic compound is a high density foam, a memory foam. I'm redesigning boxing gloves at the moment and the filling in the pro level gloves features a large portion of visco elastic foam. Very cool stuff, supposed to have good temperature regulation as well, important for the beds made out of it.

I have to say I'm tempted to use that entirely instead as I can get 100sqft for the price of 64sq ft of the butyl stuff. My only concern is being that its a polyurethane foam, it could be quite flammable, depending on how they made it and if retardants were added.

Anyone know how flammable the Butyl is? Just as a comparison.

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OH and by inside the do you mean on the inside of the outer metal door skins? I thought about that, makes fixing problems in the door easier, but I was concerned about repairs to the metal at a later date in the case of a accident.

 

[Propwash]

What is the overall thought on what that does over and above just the floor/firewall?

Sound suppression and acoustics.

 

[Dennis H]

I did the floors, doors rear package etc on the Coronet. Great reduction of noise and heat. If I had the headliner done, I would absolutely do the roof. My pal John's 70 'Cuda with the roof completed is vault-like inside.

 

[440+6]

Yea, most people it seems do the door skin itself from the inside and I think that it's probably the most effective in terms of the product doing what it is supposed to do.
But for me getting behind the window mechanisms through the small spaces in the doors and rear quarters and doing a good job at it seemed near impossible, also you can always cut an opening if you have to and then repair. That was my reasoning, I may not be right.

 

[Propwash]

Yea, most people it seems do the door skin itself from the inside and I think that it's probably the most effective in terms of the product doing what it is supposed to do.
But for me getting behind the window mechanisms through the small spaces in the doors and rear quarters and doing a good job at it seemed near impossible, also you can always cut an opening if you have to and then repair. That was my reasoning, I may not be right.

You saved yourself some trouble my friend. I did get to the inside of mine with good coverage. Problem was my forearm's looked like I got attacked by a tribe of 25 angry alley cats.

 

[tallhair]

Yea, most people it seems do the door skin itself from the inside and I think that it's probably the most effective in terms of the product doing what it is supposed to do.
But for me getting behind the window mechanisms through the small spaces in the doors and rear quarters and doing a good job at it seemed near impossible, also you can always cut an opening if you have to and then repair. That was my reasoning, I may not be right.

I'm sure it's easier if the windows are out for a full resto build which yours weren't so you did the next best thing. glad it works.

 

[67GTX440]

I just ordered some Second Skin as the reviews I read said it had great adhesion compared to the low end Dynamat. They sell factory seconds that are not 100% uniform in thickness also for a little less money. Not that that should be a big factor on the floorboard. I was planning on trying to go inside the doors, but may decide to go the inner door panel route as well. Looks a whole lot easier and my rear looks like I would have to do it in about 4 inch square pieces like a patchwork quilt. I can't see it being thick enough to create any door panel issues.

My forearms and wrists looked like I was a cutter just getting the internals of both front door locks working as they should. Sometimes you have to remove these old parts and reshape them a but with a vice and a hammer to get them to work right.

 

[Malicious]

Hmmm, my windows are out at the moment, Maybe I should do the inner skins then...

Thanks for the input guys! Appreciate it.