Bee4Me said:
I would say it's similar to what the factory used. My supplier recommended it and I'm sure no expert at the body aspect so I went with what he said.
What exactly is this whole "flutter" thing about anyway?
I have my own concept of it from the air turbulence on the skin panels and have seen some type of foam looking material on late model rides. The older vehicles i deal with just has a "tar" looking sealer which is fairly ridgid. All I know is,It does not seem to have very good adhesion.
The old cars used a sheet of dampener between the skin and brace in last 20 (or more) some years you will see a round piece of what looks like a foam or spongy urethane every so many inches inside deck lids, hoods and door skins and that is there sole purpose to keep the outer panel from fluttering or vibrating.
Depending where the brace is and strength of metal things like window sealer, panel bonding adhesive and foams can swell and shrink like Bob said.
On the 55 Chev I replaces all the tar with a shot of Duramix every six inches and it worked great.
You will notice on any of the new cars if you break a piece of the dampening agent off it may look like foam but it really a dense polyurethane for flex and strength.
First picture is from 50's, note the staples.
second picture is new see the spot blobs.
