While replacing bungs on our teak deck this summer, I ran into a board that needed replacing. There was a small hole in the board which opened up to a void when poked at. I have always dreaded the day when I would have to replace part of the deck since I had no idea how it was constructed.
Starting at the screw holes, I tried prying the board up and found it wouldn’t come up in one piece. The good news is the deck boards are not overlapped, but are simply butted together with a rabbet down the seam for the sealant. The old board was glued in place with a flexible adhesive/sealant between the board and deck.
Since removing the board destroyed it, I used a flexible, two-part casting compound to make an inpression of the board required. This compound came as two clay blobs that mix together. Press them into the void and twenty minutes later you have a flexible rubber impression for the new board.
I cut the new teak board to shape and added the rabbet for the deck sealant, and predrilled the holes.
I used TDS for sealant and screwed and bunged the new board in place. Once it weathers to gray, should fit in just fine.