ConcoursMustang Forums

1st Generation 1964 1/2 - 1973 - Questions & general discussions that apply to a specific year => 1968 Mustang => Topic started by: RichardM68 on December 06, 2024, 01:40:55 PM

Title: rear seat underlayment
Post by: RichardM68 on December 06, 2024, 01:40:55 PM
I'm disassembling the interior of my new 8F02J166xxx barn find and when I removed the rear seat underlayment, it broke pretty easily.  I believe it's original.  There's no salvaging it.  All the AM products don't appear to be the same.  Here are pics of mine.  It's yellow fiber, foil, and asphalt.  A) is this actually original?  and B) if so, where can I buy a replacement?  Everything I see at NPD and CJPony, etc, are very different.

Thanks,

-Richard
Title: Re: rear seat underlayment
Post by: 67gta289 on December 06, 2024, 02:08:41 PM
There's an article in the library that Jeff made on how to make your own.  There is not a faithful reproduction that I'm aware of.

Found it - https://concoursmustang.com/speegle/Articles/Article_Trunk_Underlayment.pdf
Title: Re: rear seat underlayment
Post by: RichardM68 on December 06, 2024, 02:17:38 PM
Thanks for the reply.  I was hoping it wouldn't come to making my own... but this car is so original I know an inaccurate reproduction will keep me up at night.

So, is mine original?  I've not seen anywhere that Ford used yellow fiber insulation.

-thanks,
Title: Re: rear seat underlayment
Post by: ruppstang on December 06, 2024, 02:21:16 PM
  I've not seen anywhere that Ford used yellow fiber insulation.

Yellow fiber insulation is used above the headliner in 67 and 68s.
Title: Re: rear seat underlayment
Post by: RichardM68 on December 06, 2024, 02:31:50 PM
So this is odd to me.  The PO was pretty specific about what he replaced, and even had the receipts.  The underlayment isn't one of those things.  I suppose he may not be 100% accurate.  I guess what has me puzzled is that, to my admittedly untrained eye, it looks original.

Presuming I don't want to make my own, as 67gta289 pointed out, who makes the closes reproduction?

Thanks,
-Richard
Title: Re: rear seat underlayment
Post by: ruppstang on December 06, 2024, 08:06:54 PM
You're under lament is without question original. Sorry I missed the quotation marks on your statement in my above post. You should look in to making your own underlayment. I find it very satisfying to make something that not everyone with a catalogue and a credit card will have. 
Title: Re: rear seat underlayment
Post by: J_Speegle on December 06, 2024, 11:20:22 PM
Presuming I don't want to make my own, as 67gta289 pointed out, who makes the closes reproduction?

There is no one currently that I'm aware of for that piece of underlayment. Just not enough call for it.
Title: Re: rear seat underlayment
Post by: RichardM68 on December 11, 2024, 01:55:54 PM
So, not to beat a dead horse... but before I posted the original question here, I emailed VA Classic Mustangs about their underlayment.  Their website says "Material is made by an OEM supplier in Michigan to original standards.  It features a durable asphalt layer with a soft needled cotton backing just like the oriignal material used in the 1960s and '70s".  When I asked about the foil, they said "The originals did not have any foil in them" and "our ST841 underlayments are made like the original".

So, is mine really original, or is VA Classic wrong?  If mine is original, I will, as suggested, make a replica.  I'd rather not replicate something that isn't even original.

Thanks... and sorry for the dead horse.
Title: Re: rear seat underlayment
Post by: J_Speegle on December 11, 2024, 02:20:30 PM
What you showed in the first post is not a version of the underlayment I've experienced but its from a 68 Dearborn car, one model and year I've not seen as much as other years or plants. Ford very often used multiple suppliers and somethings this resulted in production differences. Since other have confirmed that they have seen similar stuff used before I believe what you have is something produced by one of the lessor used and in turn known versions not used as widely as others.  Even in the dark jut based versions we often see there are differences between the arrangement of the layers and final top and bottom layers.

So IMO (having not seen either your version nor a picture of what VA is offering) you both have correct or decent examples of what was possibly used during 1968 and Dearborn plant built Mustangs
Title: Re: rear seat underlayment
Post by: RichardM68 on December 11, 2024, 02:31:19 PM
Ok.... well... I guess I need to start the daunting task of sourcing similar materials to make my own.  I prefer the car, as much as practical, match what it rolled out of the factory with.

Thanks,
-Richard

Title: Re: rear seat underlayment
Post by: J_Speegle on December 11, 2024, 04:11:38 PM
Let us know how it goes and if your successful and pleased with the results. It will go a long way helping others faced with the same issue. That's how we came up with the process I wrote that article about.  Was so happy with the results on the first try.  Good luck
Title: Re: rear seat underlayment
Post by: RichardM68 on December 11, 2024, 04:29:00 PM
If there's one thing I'm good at... it's documenting the crap out of what I do.  I'll write up a procedure and include measurements, SKU's, etc.

thanks again.
Title: Re: rear seat underlayment
Post by: warwick on December 11, 2024, 06:28:36 PM
Richard, for what it is worth; I have a Dearborn built 68 Cougar and the rear seat underlayment is a yellow (pretty bright in color) fiber . It is has a asphalt based layer (1/8") covered with paper (oil soaked I would guess from asphalt material). It is original to car.
Title: Re: rear seat underlayment
Post by: RichardM68 on December 11, 2024, 06:48:31 PM
Really!  That's interesting.  Does it have the foil too?

Title: Re: rear seat underlayment
Post by: CharlesTurner on December 11, 2024, 08:39:59 PM
I've found that style under the rear seat on some NJ '68 cars also.  Thought it was odd to use glass insulation like that, especially on a convertible.   It looks like the same material used for roof insulation, behind the headliner.
Title: Re: rear seat underlayment
Post by: lightwtjet on December 12, 2024, 01:04:55 AM
The tar underlayment beneath my rear seat no longer adhered to the floor pan. As I read about materials designed to reduce tire/exhaust noise they must adhere strongly and have reasonable mass ( perhaps 1/8 inch thick). It appears to me that is what Ford attempted to do with the tar. Agree?
Title: Re: rear seat underlayment
Post by: warwick on December 12, 2024, 06:48:22 PM
Richard-no foil.

Re: tar, I have just the tar/paper on gas tank and on floor pans and it is stuck on real good. In addition behind the rear seat a tar with clear plastic/cellophane covering (ie: no paper) is used.
Title: Re: rear seat underlayment
Post by: RichardM68 on December 12, 2024, 06:53:30 PM
Interesting yours doesn't have foil.  Because there were so many different underlayments used, it's tempting to just throw something that's supposed to be "concours" after-market in there, but this car is too original.  I'm going to try to replicate mine. 

thanks for the info.

-Richard

Title: Re: rear seat underlayment
Post by: J_Speegle on December 13, 2024, 03:47:17 PM
The tar underlayment beneath my rear seat no longer adhered to the floor pan. As I read about materials designed to reduce tire/exhaust noise they must adhere strongly and have reasonable mass ( perhaps 1/8 inch thick). It appears to me that is what Ford attempted to do with the tar. Agree?

Don't believe it was designed or expected to adhere. If so then at least one of the suppliers would have not used a very think layer of plastic during some of the years as the final top layer. Believe the tar like layers added density for both sound and heat while it would easily bond itself to the jute layer without the need for glue or addition produces. Just heat would do the job.

There were not a lot of different suppliers every year just more than a single type or supplier. From the single ply used in many of the 65-66 years to the later multiple layered ones later in the 60's
Title: Re: rear seat underlayment
Post by: warwick on December 14, 2024, 06:47:45 PM
Per requests here is a picture of the rear seat underlayment in my car. It is original to car. The yellow fiberglass insulation is only found under the rear seat. Note the white foam material is where the rear seat sits-it is original. In the rest of the car including on fuel tank it is approx 1/8" tar with oil paper-it is stuck pretty good to floor. Between the rear seat back and trunk there is a 1/8" tar sheet with a cellophane covering. I probably have some other pics if needed.