Frames for the Bulkhead hatches, deck support structure finalized

The deck support structure of the aft deck - rough blocks of ash glued and screwed in 

the idea is to create a structure solid and rigid enough to potentially allow mounting an outboard engine (even though this is a sakrileg of course, but you never know) 

on the right hand side there is one additional block to allow for asymmetrical mounting

The deck support structure for the carline within the cockpit area

Pieces of ash, doweled into the frames and screwed from the top through the deckbeams.

This is the first part of the hatches in the bulkheads, the frames

Made from Mahogany as well

And bow kingplank

just to have the complete picture, this piece of 20 mm plywood was glued and screwed
in the very front of the bow for additional strength

Here is the bow king plank dry-fitted in the notches in the deck beams and front bulkhead (this one is made of 20 mm Mahogany marine-grade plywood and glassed with epoxy).

Below the king plank one can see the block for the mast partner (35 mm solid ash)

Jig for the router to achieve a 100% circular cutout for the mast. The jig is just a piece of spruce that was cut out on the lathe.

the router bit with the bearing on the top to follow the jig

the result is a 100% accurate hole for the mast in the king plank and the mast partner block

King plank and mast partner epoxied and screwed in place.

Stern king plank

Now it is time to work on some of the key elements for rigidity and transferring the power of the sail into the hull - the king planks.

rough cutting the inner stern

Before further planing

Notches in the deck beams and bulkheads

and the inner stern

shaping the stern kingplank to fit the deck coaming

Bulkheads

Getting my head around how to create enough buoyancy in the boat, I juggled the idea of simply using inflatable lifting bodies (which I still may use) or installing bulkheads - which in addition may contribute to body rigidity of the entire structure. Also I like the idea of having some storage room etc. - all that beer on the fishing trips needs to go somewhere :-)

As for some reason I decided to use as little plywood as possible with the boat, I also wanted to make the bulkheads form solid Mahogany.

First step obviously is to create the exact pattern / template for the external shape of the bulkheads. I found the method as shown e.g. by Louis Sauzedde https://www.youtube.com/watch?v=cj3K9i9nLrE
the most easy for me.

The video explains it all, basically it works with using self-adhesive labels and a rough cut piece of cardboard:

sticky labels to create the exact shape

and the final patterns.

Next step was milling the lumber for the actual bulkheads. I used Mahogany milled to 9mm (actually the boards are the "leftovers" from boards I had sawn already to thickness for future use as the stern of the boat.

Lumber prepared...

Jig for cutting the mortises and tenons on the table saw

one of the two front bulkheads

Aft bulkhead

After glue-up

Marking the saw line with a pencil

and here is the cutting line

Dry-fitting

Final fit and gluing into place

 

same for the aft bulkhead. The solid spruce and ash pieces are already rough cut elements of the rear deck structure

Centerboard continued

After glue-up, including the bottom frame (ash)

Nobody seems to like this part (me neither) - cutting a hole in the boat just doesn't seem right.

screwholes for 5 mm x 60 mm bronze screws that where screwed in from the bottom

CB installed. Builder is very happy about this step. Actually I was slightly frightened if everything would work out fine, but it was much easier than I thought. For me placing the screws to pull the gluing seam tight worked best, I did not use any clamps.

Centerboard trial and error

something learned about epoxy...

Hole with 2 diameters to provide additional support. The idea was to fill it up with Epoxy and have a water-tight seat for the bearing

This is what happened after trying to drill a hole into pure epoxy. Some swearing involved, especially as this could have been foreseen

So everything removed with a chisel, followed by second attempt, this time thickened with micro-balloons and reinforced with fibreglass-cloth. Another - round-shaped - piece of fiberglass was laminated inside. 

Much better - the idea is to avoid water penetrating the plywood under any circumstances. There are 3 bronze bearings, one in each side of the centerboard case and one in the centerboard itself

Halves of the CB prepared for final glue-up