I performed a full dry glue-up test for this table top. This test included the clamping cauls I made. It became obvious that a 7 or 7 1/2 length bolt would have been ideal, or use of more washer. Instead I broke out my tap and die set to add more 5/16”-18 threads to each bolt.
Once the bolts were ready I did a full dry fit.
I trimmed the length of the two long boards on my table saw.
I jointed the edges of each board so I would get dead-on flat panles; I alternate the surfaces either up against the jointer fence or away from it. I follow an instruction by Fine Woodworking Magazine shown on YouTube.
I wish I would have gotten a much flatter panel, but this will do.
-- --- Happy Howie