Floor Timbers

After getting Ariadne into her new home, we decided to first embark on replacing a few of her floor timbers. The floor timbers are essential structural members that tie the backbone to the rest of the boat.

You can see how the floor timbers tie into the rest of the boat’s structure in the photo above, where the new floors are primed in orange and installed. The photo below shows the interior of the hull through the companionway, where I highlighted three larger floor timbers with a red line. The floors vary in size, ranging from approximately 2-3’ in width and a depth of up to 8” or so down in the bilge. The floors tie the keel timber to the frames, and to the planking and the skin of the boat. These are essential pieces and can be primary points of failure for lightly built wooden boats.

Some of the beefier floor timbers on Ariadne have been replaced (out of teak!) while many of them fore and aft are suffering from severe nail sickness due to the original iron bolts corroding and delignifying the wood. We began by replacing seven forward floor timbers out of laminated white oak, and will replace the iron bolts with new ones manufactured from silicon bronze.

The floor timbers were patterned and laminated up to their rough shape far away from the boat. This way, when we got back to Maine, we could simply spile the final shape onto the mocked up piece and cut the correct bevels on the bandsaw. In addition to the thicker laminate stack, we screwed a thinner stack of laminates across the top of each floor timber to reduce grain run-out and increase strength. We were inspired by the “floor timbers with wings” concept from Bud Macintosh’s excellent “How to Build a Wooden Boat.”

The new floors were primed and installed, temporarily bolting through the forefoot as the forefoot itself will be replaced next. We will paint over the red lead primer to minimize the halloween effect down in the interior. Another seven to nine floors aft of the cockpit will also need to be replaced.