DN Iceboat Hull Construction part 4

 The next step is to make the fore and aft bulkheads. The stringers are 1/4 inch plywood and the bulkheads are similar to I beams made with solid sitka spruce sides supporting an 1/8 inch plywood wall. The mast support is a sitka spruce I beam made from pieces left from cutting the hull profile. The steering post support is also 2 hull profile cutoff pieces supported by 1/8 inch plywood stringers on either side, top and bottom.

The aft bulkhead supports the seat and blocks. 

The block support is 1/2 inch Baltic Birch plywood shaped to fit the aft profile. 1/2 inch Baltic Birch runner plank supports and 1/2 inch high cockpit deck support strips are glued into the corners.

Additional 1/2 inch high strips are cut to support the cockpit deck and 1/2 inch thick foam pieces cut to fill the spaces between the supports. Note the position of the bob stay anchor and add a larger piece of 1/2 inch plywood.

Clamping the 1/8 plywood deck top over all of this would be difficult so we decided to use several hundred pounds of weights.

DN Iceboat Hull Construction part 3

Getting the stern block glued into position took some engineering and jigs. We glued the bow and stern blocks in first making sure we had the correct width (depends on sailor size and preference) at the seat position.

Next we glued in the stern structure to support the seat and tackle.

With the bow and stern blocks glued in we had our over-all shape so we cut sheets of 1/8 baltic birch marine plywood roughly to shape and glued on the bottom - lots of clamps and extra wood and aluminum force spreaders. The sheets come in 60 x 60 inch squares so the bottom is made of 3 pieces. Rather than butting the pieces together we used a 6 inch long scarfed overlap.