I'm building a simple, inexpensive workbench for my basement. The legs and underpinnings are in, and the plywood portion of the tabletop is on. I've got three 1X12s of whitewood that I need to secure to the plywood so it won't have bouncy "pockets" between the boards and the ply. My question is: screws, glue, bolts, some combination? The ply is 19/32", so screws won't have much to grab, but it might be enough.