I have a job coming up that requires a large (4’x9’) table top. The top will have a decal and epoxy so seams are not as important but dead flatness is. I don’t have a vacuum bag that big but I do have an assembly table that will accommodate.
I’ve never done anything longer than 8’ meaning I’ve always used 4x8 sheets. My practice previously has been to use MDF sheets as clamping weight. I lay the 3/4 cabinet grade plywood out, spread PL premium with a notched trowel (concerned about moisture and uneven setting of PVA causing warpage of the plywood). Then lay the next layer of 1/2 cabinet ply, and then 5 sheets of MDF. Wait overnight and repeat with another 3/4 cabinet ply. This makes a rock solid top that doesn’t deflect and allows the overhangs I need.
Since I now need a 9’ top and don’t have the ability to use longer sheets of plywood, my plan was to do the same process, but to stagger the seams between the top, middle, and bottom layers.
So just looking for feedback on my process. Anything anybody would do differently? Do I need to worry about Titebond II warping the layers? I’ve never used the cold press veneer glue. Would that be better? Should I use an MDF middle layer instead of all plywood? Plywood is obviously stronger than MDF but I’m not sure if it matters in a 2” lamination.