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.