Shaping the keel.

With the keel permanently fastened to the frames with 3M5200, it's time to work on the shape and the rabbet for the bottom. Used the same method on my 17' barrelback and is well described in Dannenberg's book.

First thing to do is to shape the keel to the correct V shape that changes over the length of the boat. Using a block, same thickness as the intended bottom, plus 3 mm (1/8") or so to be on the safe side. Then the a score is made on every frame on the keel. 12 mm for a 9 mm thick cold molded bottom. The extra 3 mm (1/8") will be faired in once the bottom is in place.

Next up is to use a plane, in my case an electric plane, to remove wood down to the score lines on the keel.

Once the keel has it's correct shape, a board with the same thickness as the wood block earlier, is temporary screwd into the frames to hold the same shape as the intended bottom later. By marking how wide you want the rabbet to be, you screw in a second moulding to be used as a depth stop for the hand router.

Then it's just to climb up and start routing. The rabbet is quite wide on this boat, 30 mm up front and 46 mm at the stern. Holding a hand router with a 35 mm diameter router bit is a little "hairy", so I opted to make the 12 mm deep cut in 3 passes, 4 mm at the time.

Matches the rabbet on the original forefoot/stem perfectly.

Keel works.

The old solid piece keel is really warped out of shape, and I will be laminating a new one. Three pieces of mahogany will be glued together with 3M5200, making a much stronger construction.

 Rough cutting a 15' (4.6 meter) mahogany slab into manageable pieces.

With the measurements taken from a string over the boat, the curvature of the keel is recreated on the work bench for gluing.

Back end keel to transom joint.

The keel is attached to the stem/forefoot with a scarf joint. carefully cut with a "japan" saw.

New and old keel side by side.

All framed up.

Over the last month, half of the frames and "knees" has been replaced, and the other half has been repaired, sanded and treated with CPES (Clear Penetrating Epoxy Sealer). The knees has been replaced on these as well. Riva did not use screws in this assembly like the American builders, but used copper rivets and burrs. I have replaced these rivets as original.

Once all the frames are inn, it's time to adjust the seats for the new keel.

I have plugged all the old screw holes in the chine, both from the bottom screws and from the outside 2 x 20 mm brass trim moulding they used to protect the chine/bottom corner. Don't want any cavities where water can collect and create problems in the future.

Next up is the new keel, where I will laminate 3 pcs. of Sipo mahogany with 3M5200 adhesive. This will be many times stronger than the original keel.