It's a plastic sphere and has 2 identical halves. Got it @ hobby lobby for a buck or so.
I used a hole saw to make my initial hole......think I used a 2.5 inch saw....maybe 3
Made a layer of "playdough" that was approx 5 inches in diameter and 1 inch thick. I pressed the bubbles hole into the playdough to make an outline then used my fingers to form the mold. Mixed the casting rubber and poured it into the mold. I set the bubble in the mold and 10 minutes later, the rubber was set. Pealed the playdough off.......soaked the bubble in water for a few minutes to dissolve the playdough that stayed on. I used a sanding barrel on my dremel tool to shape the seal/cushion. I inserted the barb and secured it with epoxy. Masked the bubbles halves with blue painters tape, then glued the 2 halves together with gorilla glue. The tape helped to keep things neat, but gorilla glue expands as it cures.....so it foamed out a little......still looks pretty good in my opinion.
Hopefully Mrs. Stryfe will give it a test-run before too long!
Later
