Author Topic: 70 trunk tar paper insulation  (Read 371 times)

Offline redmach69

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70 trunk tar paper insulation
« on: March 28, 2017, 11:52:00 AM »
Hi Guys I believe I'm going to need to replace the gas tank in my unrestored 1970 mach 1, is there a way to remove the insulation (which is intact) without destroying it? It is the tar paper type with the thin plastic on the backside. I saw on the 302 forum that dead nuts on is supposedly reproducing the underlayment but I don't see it on their site. Also to further complicate things, my trunk mat is glued in the center to the underlayment. And the mat that goes forward of the tank and runs under the back seat appears to have been put in upside down, the thin plastic layer is up and the tar paper down. this is not a problem just interesting I thought. Should I keep the original tank as I have been doing other original things (belts, hoses, plug wires etc.) or is it just a tank with no important characteristics?
Thanks for any Ideas.
« Last Edit: March 28, 2017, 05:05:18 PM by J_Speegle »

Offline J_Speegle

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Re: 70 trunk tar paper insulation
« Reply #1 on: March 28, 2017, 05:34:53 PM »
Hi Guys I believe I'm going to need to replace the gas tank in my unrestored 1970 mach 1, is there a way to remove the insulation (which is intact) without destroying it?

The underlayment is likely brittle and is heavy so it will likely crack and brake when you remove it. You can cut sections of heavy cardboard to try and slip under the main sections from inside the car (through the trap door and have others support the "wings" as you remove it but thing the results will still cause damage


It is the tar paper type with the thin plastic on the backside.......

That is one of the versions - seems to depend on who the supplier was. Sometimes its paper on both the top and bottom - other times its paper on one and the thin plastic sheet on the other - like someone skipped a step and forgot to remove that layer and add the paper.



Also to further complicate things, my trunk mat is glued in the center to the underlayment. And the mat that goes forward of the tank and runs under the back seat appears to have been put in upside down, the thin plastic layer is up and the tar paper down.

No they installed them both directions - when they used that style of underlayment. That forward section would be a continuation of the forward installation that included all the stuff they put under the seats and front carpet


this is not a problem just interesting I thought. Should I keep the original tank as I have been doing other original things (belts, hoses, plug wires etc.) or is it just a tank with no important characteristics?

IMHO everything is a important characteristic especially in an unrestored car - unless you are having issues like it rusting through, leaking or other issues

If you haven';t found them yet using the search feature there are a number of threads and an article posted in the Library on the subject of this underlayment and a method of reproducing it
Jeff Speegle

Anything worth doing is worth doing concours ;)

Offline tobkob

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Re: 70 trunk tar paper insulation
« Reply #2 on: March 28, 2017, 09:48:17 PM »
Quote
If you haven';t found them yet using the search feature there are a number of threads and an article posted in the Library on the subject of this underlayment and a method of reproducing it

+1...I reproduced the underlayment for my '69 using Jeff's instructions and am well pleased with the results.

TOB
1969 (04/07/69) GT350 owned since 1970

Offline 7Lscjracer

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Re: 70 trunk tar paper insulation
« Reply #3 on: March 28, 2017, 10:18:54 PM »
...You can cut sections of heavy cardboard to try and slip under the main sections from inside the car (through the trap door and have others support the "wings" as you remove it but thing the results will still cause damage

My thoughts exactly, but I'm picturing using some Home Depot thin plastic flexible sheeting like what I used to make my moonskin sail panels out of instead of cardboard.
Thin but strong, and cuts to size to work like a giant spatula.
Like a sheet of arborite or melamine , but not all brittle.
69 Mach 1 San Jose Nov. 68 build

Offline rockhouse66

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Re: 70 trunk tar paper insulation
« Reply #4 on: March 29, 2017, 09:14:06 AM »
Dead Nuts On does have this material.  I thought it was on his website but you can call or email him for info.  It's very nice stuff.
Jim
'66 GT FB, '69 CJ Grande