I'm new here so my reply may be too late to be helpful.
I wonder if any of the mold releases in the marketplace might work, or some way of incorporaing teflon between the EPDM and the metal. I'd try looking on Google using the search term "mold release" and distinguish between sprays and more...
I'm not sure EPDM would have enough tensile (1500-2000 typ psi) to work but what about urethane film (4000-6000 tensile), heat sealed with an inflation fitting? Urethane films are readily available, EPDM is not. Urethane (tpu varieties) is heat sealable; EPDM is a thermoset and would have to be...
Your post has been here for a time so you may have solved this; however, if it's helpful, most silicone compounds tolerate 450 deg F before losing properties and compounds with red iron oxide fillers can tolerate excursions up to 600 deg F (but NOT constant exposure). Testing is essential if...
I want to second the idea that testing is essential since almost ALL rubber compounds are custom mixed for a particular rubber manufacturer and results can vary widely, even for a 75 durometer (Shoire A) compound with 2700 psi tensile. One rubber company's recipe may have five ingredients...
By way of disclosure, we also supply both silicone and rubber tubes, mandrel formed or extruded, and O.D. ground where necessary for precision. There is usually one best method for each application and you probably will want to survey natural and synthetic rubber compounds ($1-2 per lb.)for...
You might consider using urethane as a replacement for natural rubber. It is the only flexible material with higher overall strength than natural rubber and recall a pencil eraser, natural rubber tends to harden over its lifetime whereas urethane won't. One of the problems with any rubber...
