When glueing up a Centerboard trunk , it can be difficult to keep the whole thing aligned when clamping due to to glue causing get the pieces to slide around. You can control this process by doing what violin makers have done to keep the parts of a violin from doing the same thing while glueing up.

Assemble the center board trunk for a dry set up. Get all the clamps into place that you are going to use.

Drill thru on both sides of the center board trunk a hole using a 1/16 bit in each corner through the plywood and into the solid wood parts in all 4 corners. 8 holes in total. You will be using a round wood toothpick as a alignment dowel.

Apply your glue as directed in the manual and push a toothpick into the 4 holes on one side thru the plywood and into the solid wood. Break off the end of the toothpick at the level of the plywood. Now do the same for the other side . The toothpicks should now keep the trunk in alignment while you attach your clamps carefully. Clean up squeeze out as needed.