bjbrown wrote:I've been led to understand that applying the insulation/sound-deadening material inside doors make them close with a much more satisfying sound than as they are without. Anyone used that kind of material in the doors?

I bought a 10 piece Hushmat door kit back in 2013 for about $70; used about half in various places, including the doors. The closure sound is a bit more solid, but the best reason is to offset the drumhead effect of the steel door panels from road, wind, and other vehicle vibrations. Make sure you use something like a veneer roller on installation, or you'll get practice re-installing your door cards.... . I'm happy with the result, but I note Hushmat's prices have increased quite a bit.

Neil

I put the Eastwood equivalent of Dynamat in my doors. I'm not sure it did much and it was a little bit of a pain to put in. I pulled the glass for another reason. Without that it would be more than a little bit of a pain to put in.

Personally I am reluctant to put more than some thin sound material between the door cards and vapor barrier when upgrading the sound proofing in the doors. Where the window regulators and mechanisms exist is a wet area so any insulation you put in that area has the potential to trap water and promote rust from any rain storm, snow, washing or even a heavy dew. In the back seat area water can just flood in at the quarter windows and if the collection system of funnels, drain tubes, etc are not 110% intact there will be a greater potential for rusting in that area too if you insulate it.

There is a product called "Lizard Skin" that I saw demonstrated at SEMA. It is a spray or roller application, in the demo they used a plugged in hot plate with one half coated with a 1/6 inch of product, the had ice cubes lining the bottom, the untreated side was steaming and sizzling the treated side was cool to the touch. Very impressive, I would have used it however I have no painting skills...I am using Dynamat.

My question was assuming that sound deadening material would be installed inside the door and not behind the door card. Since my 1980 has two horizontal strengthening ribs attached to the inside of the door skin, applying this material would be a challenge even without the internal window/mechanism in place as aj81spider said. My plan was to paint rust-proofing, apply seam-sealer and then install my Eastwood ("Dynamat equivalent") on that inside surface of the door skin, going over the strengthening ribs and all.

Thoughts?

I don't think there really is any need for this stuff inside the door. Most of the sound in a convertible is high frequency stuff, and the low frequencies, which the sound deadening helps with, are generated by the running gear and road contact points. Doing the floor pan is plenty good enough.

I would not put insulation in that location where water would run down over it regardless of the rustproofing I used. The wet insulation would develop mold and mildew over time and prevent the door from drying out after a rain storm or the car was washed. The door card vapor barrier and insulation should be sufficient and would be the only place in the door that I would consider upgrading insulation aside from applying one of the spray on bedliner type insulating products being careful not to plug the weep holes.

Examples of spray on sound deadening (note those that are listed as appropriate for use on door skins):
http://www.amazon.com/s/?ie=UTF8&keywor ... 4ii3kyph_b

If you Google "Dynamat door" you will find a diversity of opinions (just like here). The principle behind Dynamatting the door is not to filter sound coming through the door (pointless in an open car) but to prevent the door panels from generating noise via vibration. To me, the outer skin is going to vibrate much more than the inner skin, so I did that. I suppose there may be a chance water could get trapped behind it, but I sealed the edges with aluminum tape, and the mat itself is adhesive tar (and I don't drive my car in the rain) so I think the probability is low. The mat itself is tar and aluminum, so I think it's pretty unlikely it will develop mold and mildew.

All that said - I didn't notice a huge difference after I installed it, although the doors do clunk closed a little lower pitched.