Scarfing Ply

[Gaff]

The deck of my boat has a base layer of 20mm T&G boards with 6 mm marine ply on top glassed over. I have just replaced a few of the boards that had rot due to water getting into the end grain where the mooring bit is. Do I need to scarf the new piece of ply before gluing or would a bit joint be OK. Any thoughts much appriechiated. Jim

[gaffman]

From one gaffer to another. Given the small area involved, and that I don't know of a jig you can use to scarph the piece that is still on the deck, I would just half-lap the seam. It's a lot easier to do to the piece on deck. Just set a router for half the depth of the plywood and set up a fence and have at it. Cut in maybe 2 inches from the edge or so. Glue and bronze ring nail through the half-lap, and it'll outlive both of us. That's what I would do.