I saw an article - can't find it at the moment - where the author used several pieces of PVC pipe to raise the glued panel off the workbench and allow him to slip the clamps under the panel as he worked. The pipe would be parallel to the clamps, perpendicular to the boards. I would be using pipe clamps for the job - don't have enough of the big fancy clamps - so probably 1-1/2" PVC would allow clearance to slide the clamps under the wood. And the glue won't stick to the PVC which is a bonus...........