1960s Masticated rubber exhaust hanger

[David Greenburg]

I need to replace the exhaust pipe isolator on my '61. This appears to be some kind of masticated rubber-basically a flexible sheet with a hole in the middle for the pipe to pass through at the point where it passes through the frame. It's easy enough to find sheets of masticated rubber, but they appear to be intended for use in splash shields, and I'm concerned about heat resistance. To the extent that I can find any temp. specs, the stuff is rated to 250 deg. F, which doesn't seem high enough for direct contact with the exhaust. Anyone been done this road and have a source for heat resistant material?

[The Tassie Devil(le)]

G'day David,

What I use is old Conveyor Belt Rubber.   This stuff is any thickness you want it to be, and has a series of Canvas inner layers for strength.   Another name for it is Insertion Rubber.

I have even seen people use old tyres where they cut the sidewall out.

Bruce.

[Tom Boehm]

I had a similar situation with a non Cadillac car. Waldron's Exhaust sold me a piece of rubber exhaust hanger material. www.waldronexhaust.com   

[Clewisiii]

Conveyor belt rubber or cloth inserted SBR rubber.

[Clewisiii]

Would need to verify the thickness. But it is either 1/4 or 5/16.

[David Greenburg]

Thanks. Some good ideas here. I started down the rabbit hole of heat resistance for various types of rubber and started to wish I had a degree in materials engineering. There's enough left of my old one that I can confirm the thickness. I would have guessed it was thicker than that.  Although I suppose its not really bearing weight; its just keeping the pipe from moving too much.

[David Greenburg]

Looks like the SBR rubber will do the trick. I was concerned about the heat, but it  out that the pipe at that point is only around 130 degrees F at that point, so there's no need for anything more exotic. Very interesting  running an infrared thermometer along the pipe.

[Classic]

FWIW, McMaster-Carr sells various sizes & types of SBR rubber.   Search for "SBR Rubber".
Gene