My grandson got a train set for Christmas and it will take 2 sheets of plywood to accommodate the track. I figure to put the plywood on 2X4's to make it rigid and some sort of stand. But I haven't figured out an elegant way to join them together smoothly for the track, that can be undone for storage when needed. Run bolts through the 2X4"s? Anybody have to join 4X8 plywood together to form a smooth edge, their ideas would be appreciated!