I definitely used it as per instructions. I also used screws every 3"
to hold stringers to the ply with the Gorilla Glue. When I took the
boat apart, I was easily able to pry them apart after removing the
screws. There is no doubt there was sufficient clamping force.
In my furniture repairs, I also followed the directions and clamped
things well and the Gorilla Glue failed. I do not believe I am an
idiot so I tend to think that if I followed the directions and was
careful and it did not work, there may be a problem. It seems that
epoxy is more firgiving.

I prefer epoxy, but I find Gorilla Glue is the better
glue when your wood is very wet & green, or if you
are working outside in the rain.

Epoxy doesn't stick with very wet conditions,
but Gorilla Glue sticks best when water is
present. Indeed, I usually wet down the
mating surfaces with a spray bottle of water
prior to applying the glue.

I would use Gorilla Glue more if it weren't
so expensive. Thickened epoxy is cheaper
and usually better.