Deadwood and Sternpost – Sam Allen's Boats

From about the middle of the centerboard slot and aft to the transom, the ballast keel’s upper surface slopes downward, leaving a wedge-shaped opening between it and the keel plank. This gets filled in with a large wooden piece called the deadwood. Aft of the deadwood, a separate piece called the sternpost will be fitted.

The deadwood has a curved upper surface that abuts the keel plank and tapering, slightly curved sides that extend down to the ballast keel. I began by building up a deadwood profile template using thin plywood pieces to fit the opening where the deadwood would be.

I built up a plywood template to lay out the deadwood’s profile.

Douglas fir is specified for the deadwood, and what was readily available and of sufficient width was 2 x 10 planks. I cut them so I could glue them, stacked in a tidy pile, to make a blank from which the deadwood piece could be sawn to shape.

I made the blank for the deadwood by gluing together pieces of 2 x 10 Douglas fir planks. I’ve used my template to mark the outline of the deadwood profile on the face of the blank.

The glued-up blank was hefty and definitely too large to cut to shape on my 14″ bandsaw. But boatbuilder Alex Hadden was willing to make the cuts for me on his industrial-size saw. We began by making cuts to bring the blank close to its final shape in profile.

The deadwood is too large to cut on my band saw, so Alex Hadden helped me by making the cuts on his much larger saw. It’s capable of 16″ deep cuts, just enough to make the largest cuts on this deadwood blank. I’ve laid the pattern on the blank to mark out the first set of cuts.

Alex is making the last of three cuts to get the deadwood close to its final profile. Here he’s cutting the surface that will adjoin the sternpost.

The broad faces of the deadwood are curved and have a slight winding bevel. We decided it would be safest to keep the bandsaw’s table at 90 degrees for rough-cutting these faces, and then I could finish tapering the sides using hand planes.

Here Alex has begun making the cuts that will become the side faces of the deadwood. I gradually raised the blade guide as the cut progressed. It opened up to a maximum of 16″—just enough to accommodate the deepest part of Justine’s deadwood.

After sawing, the deadwood is close to its final shape. Because of the extensive tapering of the shape, there’s quite a bit of wood to cut away from the original blank.

The big bandsaw cuts are done. I still have to cut the opening for the centerboard slot (marked out and visible here), and bring the blank to its final shape using hand tools.

I used my No. 7 joiner plane to smooth the two flat faces of the deadwood, and both a compass and block plane to smooth the curved face that adjoins the keel plank. For the slightly curved, broad side faces I started with a scrub plane to do some of the tapering, and was able to use smoothing and block planes to bring the sides to their final profile.

I’ve smoothed the deadwood with hand planes. I made an impressive pile of shavings, some visible on the ground here.

I was able to cut the centerboard slot in the deadwood on my 14″ bandsaw, then it was ready to put in place and drill for the keel bolts that need to pass through and secure it.

Checking the deadwood’s fit. It’s ready to install.

John Peterson helped me prepare and fasten the deadwood in place. We used more roofing cement and canvas to bed the deadwood, as we’d done for the ballast keel.

The sternpost attaches to the aft end of the deadwood. Its primary function is as a strong attachment point for the rudder, so it’s made from a piece of white oak. The sternpost also serves to seal the deadwood’s end grain, which could otherwise facilitate transport of water into the deadwood. The sternpost is tapered so that it fairs smoothly into the deadwood’s shape, and match the butt of the ballast keel at the sternpost’s lower end. The three mating surfaces of the sternpost get the same roofing cement/canvas treatment as the ballast keel and deadwood.

John Peterson helped me install the deadwood and sternpost. Sternpost surfaces have been coated with a thin layer of roofing cement, a layer of canvas, and it’s ready to bolt in place.

Once the sternpost is bolted in place, there’s lots of squeezed-out roofing cement to clean up. John’s getting a start, using a putty knife.

Deadwood and sternpost after installation. Two large bungs are visible on the aft surface of the sternpost. (They have not yet been trimmed flush.) The bungs cover carriage bolts that extend up through the deadwood and keel plank. Two of the rudder’s three bronze gudgeons (rudder attachment fittings) are in place near the bottom and top of the sternpost. Both the deadwood and sternpost have been darkened in the process of cleaning up squeezed-out roofing cement. Both parts will get a coat of red lead prior to application of bottom paint.

There’s one last piece of the underbody to make and install: a fairing piece that fastens to the keel plank, just ahead of the ballast keel. It extends forward in a graceful curve that fairs in to the shape of Justine‘s stem.

A piece of white oak is shaped and fastened ahead of the ballast keel to provide a smooth, fair shape to this part of the hull.

The last two photos were taken on August 16, 2016.