It shouldn't be that fine of a line. I've had 6' pieces of glass bow out 1/4" with no ill effects. Pink foam doesn't compress that much, does it?
A couple thousand pounds of water and rock pressure on the bottom glass should balance out the downward pressure from the edges. That would result in less pressure on the edges.
(just trying to wrap my head around the physics of the foam problem)
Mitch
|