Stack and glue two of the pieces together and stack and glue the other four together the extra thickness is required to give the go bar deck base sufficient stiffness.
Go bar deck.
The deck consists of two double pieces of plywood a floor and a ceiling separated by four pipe nipples and flanges at the corners.
The second part of the equation is to press it all into a disk with the correct radius but that s not todays problem.
The go bar deck or the use of bent sticks between two solid surfaces is a very old method of applying clamping pressure while gluing two parts together.
By bending fiberglass or wood rods between the upper and lower decks it is easy to put pressure just about anywhere you need it.
In the picture the upper transverse brace is being glued to the top of an acoustic bass guitar.
After trying a couple of alternatives from the local big box store as well as my back yard i broke down and bought a set of 3 16 fiberglass rods for the go.
Go bar deck assembly from a sheet of 3 4 plywood cut six pieces each 2 feet x 2 feet.
The bars worked well when left 1 2 3 4 longer than the clear distance to the upper deck.
The deck is roughly 2 feet square and 2 feet tall.
Now you could just use lots and lots of expensive clamps with many cauls but most luthiers use what is called a go bar deck.
The compression bars are made from straight grained maple with a 3 16 x 3 8 cross section.
What you are looking at is a go bar deck sitting on the extension table of my table saw.