GPW wrote:WOW!!! That should Never come apart ...
But did. Total failure at the thin plastic coating they put on this stuff.

Peeled the skin off the other side of the same two pieces (as they were the last of the scraps I had in the house), perfed and coated both pieces this time with GG, as only the coated piece had the holes well filled with the foamed GG. Also really worked the GG into the holes, as last test I just wiped it on. Misted one of the pieces, put them together, and have them clamped again. So far lots more foaming around the edges. Should be ready to test in an hour or so, but I may wait till tomorrow for it to totally cure.
One thing I noticed, prior to really getting down on it to try to rip it apart, was how stiff the glued together piece was. Compared it to 2 pieces about the same size just held together and could flex them but the glued piece was like a piece of plywood, no or at least very little flex.
Pictures of the failure and regluing below.