I recently added Dynamat sound deadening to the roof of my car. I was not able to find much detailed information on how to do this so I thought I would post my experience and results.
First I pulled down the roof upholstery and its foam backing. This was a very messy process, as the foam backing crumbled and created a large amount of dust. I covered the entire underside of the roof with Dynamat, cut to shape. Dynamat is a tar based mass-damper with a foil backing; its uneven surface and seams make it unsuitable to adhere the vinyl headliner to, directly. Next I shaped a thin sheet of Coraplast, purchased from a local sign shop, to fit in the roof using the vinyl liner as a template. I thoroughly washed the headliner on both sides, scrubbing off the old foam backing remnants. I was able to tuck the Coraplast into both the left and right sills, above the doors.
Once I was satisfied with the fit of the Coraplast, I took it down and sprayed it with 3M vinyl adhesive and placed the headliner carefully. Next, I sprayed the underside of the roof with the adhesive and quickly assembled the Coraplast headliner and side sills in place.
The result is a very smooth and stock appearance. It maintains the original bowed shape of the roof and does not vibrate or oil-can. I did lose some small amount of headroom due to the added thickness of the Dynamat and Coraplast-- perhaps as much as 1/4" compared to stock. Importantly, it eliminates the roof as a source of tinny noise, increasing sound quality. Below is a picture of the final result.
Attachments
Images (1)
Original Post