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