The good news is: You can't. The glue line can be incredibly thin and still hold (in fact, some glues require it). To physically over-clamp to the point of glue failure would actually destroy the wood itself. When I heard that, I was a little skeptical at first, but when I really thought about it - wood is super porous on the surface - you wouldn't get near enough glue out to make a difference unless you "unwring" the sponge, so to speak - which would destroy the wood itself.
Originally Posted by Rob Keeble
You simply can't clamp too much
This is a very cool video. I noticed some techniques that were interesting - like instead of kerfing for the inside of the boxes, he had separate little tiny wedges that he placed instead. Or that the back bracing was done inside the box first, then barely glued to the braces in the center to get it positioned right. Very interesting, indeed.