I disassembled my new welsh mounts in order to center the bushing before installing them. I've read it doesn't make any real difference but I wanted to start out centered. While apart I trimmed the flexible material to allow it to center and then filled the void between the 'material' and metal housing with hi temp (600 degree) rtv.
The mounts felt very plyable, the upper section with bushing more so than the bottom ring. Just out of curiosity I put some heat to the trimmed material and LOW and BEHOLD the material is a Thermoplastic polyurethane. The upper section will melt at 220(f) degrees and it softens quite a bit at 185(f).
The bottom ring melts at 235(f) and starts to soften @ 200(f).
I'll be installing my workbench full of parts pretty soon, I sure hope the Texas heat doesn't hasten the demise of these Welsh mounts.

wj

 

Now that is very interesting, but even in hot places, could a shock mount even reach 180ºF while driving around?

 

Jon89 and I discussed this a month or so back when this first came up.
We did his several years ago and one of the problems we had was compressing the poly.
Looking at the problems with the newer install, our conclusion was they changed material, that simple.
What a shame, wonder how much money they saved.

 

Probably not, but that thing sitting next to the shock mounts (the engine) is regularly 200-220F and the properties are a continuum. Softening/melting in or below this temperature range seems like counterintuitive behavior since it might lead to more compression/failure (softening leads to higher internal velocities into 'resistance' leading to more deformation).