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Vapor barrier or Dynamat behind door panels

Sonny

It’s all fun til the rabbit gets the gun.
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Any opinions on this? Was thinking about using Dynamat on the front doors to reduce the rattles.
 
Your asking for opinions. Here's mine. I think dynamat or similar products stuck to the outer door shell will promote rust in the future. If you're looking to reduce noise and want to use a product like that, first seal the inner door with POR-15 to encapsulate and stop rust. Then install your regulators and door hardware and use the conventional clear plastic water or vapor barrier. I would rather use nothing as the factory did than make the car subject to rust in the future. Personally I seal the inner door with POR-15, and then build it like the factory did. If your hardware is installed correctly you will not have rattles. I also think anywhere dynamat is used that the surfaces it goes on should be protected first.
 
Your asking for opinions. Here's mine. I think dynamat or similar products stuck to the outer door shell will promote rust in the future. If you're looking to reduce noise and want to use a product like that, first seal the inner door with POR-15 to encapsulate and stop rust. Then install your regulators and door hardware and use the conventional clear plastic water or vapor barrier. I would rather use nothing as the factory did than make the car subject to rust in the future. Personally I seal the inner door with POR-15, and then build it like the factory did. If your hardware is installed correctly you will not have rattles. I also think anywhere dynamat is used that the surfaces it goes on should be protected first.
I agree, good air circulation, drainage and no metal unpainted. If you want sound deadner put it between plastic and door panel. If you hear rattles your exhaust is too quite!
 
The ONLY purpose of the vapor barrier was to protect the masonite door panel from getting wet and disintegrating - nothing more. That said, if you plan to drive the car in heavy rain, snow or sleet or wash it every week, then be sure to install the vapor barrier.
 
I was going to stick it to the inner most side of the door between the door and door panel.
 
Refer to post #2
I read post 2. He said “outer”. I said “inner”. I’m not putting it on the back of the outer door skin, instead between the door card and structural inner side panel.
 
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Too thick, the panel likely won't fit properly. Also, that stuff sticks like snot. If you have to get inside the door you'll have to cut the access holes out. Personally I'm liking the idea of spray-on sound deadener. And FWIW, the factory did spray **** in there, here's proof:

IMG_0901.JPG
 
I read post 2. He said “outer”. I said “inner”. I’m not putting it on the back of the outer door skin, instead between the door card and structural inner side panel.
Ok, if it's very thick then your door panels will stick out, and you still need a vapor barrier. I don't know how thick it is. You asked for opinions and now your trying to argue about it. It's your car do what you want. I was just trying to offer something.
 
Play nice boys! Frankly I can't see how dynamat or any similar product is going to "reduce rattles" !! If you ave rattles, fix the damn things!
 
I used hush mat on the inside of my outer door panels to reduce road noise and tinny sound when shutting the doors. All weatherstrip replaced and anything that could rattle is fixed. Hush mat is sticky enough, no water or air is going to get inside of it. Just make sure what it is stuck to is clean. and use something like a roller to press it on. .. I will be dead and buried before it ever rusts ..........................MO
 
Ok, if it's very thick then your door panels will stick out, and you still need a vapor barrier. I don't know how thick it is. You asked for opinions and now your trying to argue about it. It's your car do what you want. I was just trying to offer something.
 
No worries. I should have written the question better:

“I’m installing new door cards. Should I install standard vapor barriers or use Dynamat”. Pros and cons to either. Thanks!
 
Not something I have given any thought to. But I suppose I would get a bead of that super sticky black snot all around the outside perimeter and slap some plastic over it. The Audi had this in it's doors. looked like it was a good idea to me. The stuff compresses so the door card will still sit flat. My Coronet doors have factory sealer sprayed on. Might touch up the spots first then do the plastic.
 
As others have mentioned the dynamat is thick and would be terrible if it had to be removed. I made vapor barriers out of the plastic covers mattresses come in. It’s thick and I used Eastwood’s 1/4” strips of black mastic sealer because it was easy to form around the door and rear seat panels. I did use dynamat on the inside of the door skins for a sound deadener.
 
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