My next task is to fashion a flexible prop to wedge up under the bottom so I can begin on the second layer. This is important because the 6mm ply flattened off between the bulkheads, leaving high points. I also have left the edges free of glue so the planks can move. The prop will push it back up and provide some resistance to the attachment of the next layer.
I am going to be using an unfamilar product for this next task; Purbond. Apparently it is very fast to apply and fluffs up with a mist of water, filling voids. I expect the speed of application has a lot to do with it being a single part glue…haha! No mixing!