I just saw that Woodpeckers is offering once again their phenolic clamping cauls. Not wanting to be castigated as a Woodpeckers shill...they really are nice. I've glued a 4' long surface using only using 2 clamps. The pressure is spread equally along the entire surface because of the curvature of the caul. Take a look, they're pretty sweet. https://www.woodpeck.com/onetime-tool-clamping-cauls-2019.html