Hi,
The guy who will inslall the window glass in my studio doesn't know EPDM rubbert or closed cell used in Knightfly sketchs. But In the SAE site window construction uses "easy to found" material: Silicon and Cork or Rubber:
External image, not preserved — original: http://www.saecollege.de/reference_material/images/Windows_2.gif
Will it works at least 10 years?
This is the Knigtfly sketch: