i think half the problem was that bear paw glass is worse quality than i thought. there is fiber streaks all through it!
also like fujimo said, i was probably to rough when filing the edges of the glass.
as to the rubber band method... there is quite a bit of pressure on the outside or edges. but it was a bit wide when it came out of the form, and at that point in the handle its quite far in..
hm,
well I've clamped above it and lifted the glass a little with a blade and put some ca glue in there. that seemed to go in nicely, so well see what happens!
Cheers,
Jacob