Topic: 65 Dearborn FB - Trunk sound deadener (Underlayment)

[tomtri66]

Gentlemen, Thank you all for the help.
Just one final question. Does the original underlayment that you two guys have in your cars have any tar coating at all ?
If not then the CJ Ponyparts sheet would not be strictly correct. The CJ part looks to be coated on both sides making removal difficult.
If the originals did not have tar I will source some underlayment over here.
Thanks

I actually have one of these CJ Pony Parts underlayment pieces that I have yet to install.  It is a rubber/tar (not sure if the exact material) mat about 1/8" thick similar to the material you would find under the back seat or under the carpet.  There is no jute material at all.  What is curious is that according to everyone in this post there was no such piece installed at the factory which poses the question, why CJ lists it as the underlayment for 64-68 top of the tank.  Can anyone shed light on this?

[CharlesTurner]

Well, consider that this is what was used at that time in Dearborn.  San Jose and Metuchen might have been using different materials.  I have seen some tar-backed pieces used on top of gas tanks, but don't recall which year or plant.

[cobraboy]

My observation over the years is that all body style 76 (conv) had or were meant to have the jute underlayment.  Without this the "sloshing" of the fuel while driving is very evident and not in step with the expectations of a mid sixties buyer.  The top of the tank was the ONLY place that a sound barrier could be incorporated since the divider between trunk and cabin is pretty well taken up by the well and the folding top and associated parts.  The coupe was intended to have the same jute type insulation/sound barrier placed on the vertical section behind the back seat which serves as a divider between the trunk area and the cabin.  In addition some type of material was used on the little body panel that seperated the tank (floor) from the vertical section.  This silences the gas slosh and I suppose in addition provides a little thermal  insulation between the cabin and the trunk.  The fastback body style is open for discussion.  The 65 interior FAM shows a jute insulator was used, but the 66 for some reason does not show any.  I have a 65 fastback with deluxe interior built April 22, 1965 which, as far as I can tell did not have the jute sound insulator.  Could it have been there when the car was built?  You bet it could but it had the original mat still in place in 1984 when I purchased it from the second owner but no jute mat.  Seems odd it would have been removed but there is no way of telling.  I have agonized over this question for almost 30 years and have looked at several examples and have come to NO conclusion about the fastback and I hope that someone will provide images or proof that this insulator was or was not incorporated in a Spring of 65 fastback built at Dearborn (or anywhere else, too).  Look at the dates in both the 65 and the 66 FAM drawings of the trunk area and post what you think about the change date shown.

John
That is interesting. I must say I have not heard any sloshing, but as I tame more and more of the 'little noises', newer less obvious ones present themselves. As our cars are so close together it is interesting to hear that you did not have anything there.
Mark

[MWM]

Cobra,
I have worked with Ssnake Oyl Products in the past and they are exceptional!  If you can't find the jute insulation locally try: http://ssnake-oyl.com/
Good Luck and keep those photos coming!

[cobraboy]

Cobra,
I have worked with Ssnake Oyl Products in the past and they are exceptional!  If you can't find the jute insulation locally try: http://ssnake-oyl.com/
Good Luck and keep those photos coming!

I'll have a look at what they have, thanks for the tip.
Mark

[J_Speegle]

Used the bulk stuff for making the underlayment for the 69 last time. We had to put together two panels (stripping out on jute layer) to get what I wanted for that application. The single sheet had

One layer thin clear plastic
One layer tar
One layer jute

Hope this helps

[cobraboy]

I read your post on that, very impressive.
I emailed Snakeoyl but as yet do not have a reply.
Thanks
Mark

[MWM]

Mark,
If you don't have a response by the mid of next week, send me a PM and I try and help out.  I know the owner, he is quite helpful and knowable.
Thanks!

[cobraboy]

Mark,
If you don't have a response by the mid of next week, send me a PM and I try and help out.  I know the owner, he is quite helpful and knowable.
Thanks!

Thanks I appreciate that.
Mark

[C5ZZKGT]

-Looked at the info/picture on their site and it looks like ita all jute-then they say its a multi layer product-do we know the thickness? are we sure its 100% correct for the '65 Mustangs?