Packard Forum Index » V-8 (1955-56)

I just purchased a dyna-mat product and I'm looking for opinions as to where I should strategicly place it inside my 400? Have any of you used such a product before? (I purchased about 30-35 square feet of the stuff)

One websitequietride.com/index.html shows the car pretty well covered for both noise and insulation with their acousti-shield product while on the dynamat page it says you can cut into strips and don't need to cover the entire area to achieve a substantial nose reduction. Doesn't look like the dynamat does much for heat control. Personally, I would put something on the roof for both and use the dynamat on rest of the panels.

One of the products I've used with some success is:
Flexible Foil-Faced Bubble-Wrap Insulation 5/16" 9367K33 $30.93 for 25ft
from Mcmaster-Carr. I covered the floor with it for sound-deadening and heat insulation. The number in bold is McM-C's part number.

Interesting topic. Don't think I've seen sound deadening discussed before here. Restoring (in my imagination) my (so far non-existent) 400, I have thought about insulation, both for sound and heat (keeping cool as well as warm.) If I had to re-do an interior it would be a given to do this.

But I was wondering how much insulation, if any, is already between the headliner and the roof from the factory. This is a critical area, especially for keeping cool without AC. I've read experiences of restorations of other makes regarding headliner insulation and very good results for keeping interior temps down in summer. (However, I think it would be senseless to tear out a good headliner and replace it just to add insulation--especially if there is already some in there.)

I know it's never too hot or sunny in Arizona, Kevin, but thought you might be considering this application for your 400 if the headliner is in need of replacement! Sorry, I don't know what phase of work you're on with your 400.

As I recall, the only thing Packard had on the roof was asphalt impregnated felt which covered the central portion--maybe 3-4 ft square & 1/8 inch thick or so. Similar small piece under the seat.

The pre war AC cars used a quilted insulation on the roof - LeBaron Bonney's is a good replacement. I got the single sided foil to make sure of a good bond, and used a recommended 3M adhesive as instructed

Dynamat comes from the car-audio world and is usually a pretty weighty sheet of "rubber"like material glued to a body panel to reduce unwanted body vibration from the bass speakers.

Usually it's applied in squares in the middle of large panels. The weight on this stuff adds up quickly. I would add a good size square to the middle of the roof to reduce panel vibration first, and then cover the entire roof with a good foil backed insulation for heat and sound reduction. Same with the floors. Dynamat is expensive, so just use it for the vibration reduction, and use the foil back insulation for everything else.

Make sure you use a very good adhesive on a clean prepared surface as you don't want that Dynamat falling down on your headliner while driving on a hot day.

Just my