Last summer I replaced Sedna's canvas dodger with one made of marine plywood.
I began by cutting the arc that I wanted in two lengths of 1"x12" pine. I made a temporary box frame with these boards and 1"x2" boards for the sides. I then screwed a rectangular piece of 1/4" marine plywood to the arc of the frame starting at the center line and working out to the sides.
I attached temporary legs to the corners of the frame. Adjusting and trimming the legs, I was able to position the frame over Sedna's existing windscreen. Webbing attached to the boat held everything in place. I heated up water in my electric kettle and poured the water over the bent plywood. The idea was to "steam bend the arc into the plywood" dried to minimize springback when the frame was removed later.
Next, I went underneath the top and cut cardboard templates for the permanent frames that would attach to the existing aluminum windscreen frame.
The templates were trimmed to fit and labeled.
Plywood panels were cut out to match the templates. The panel edges were cut and shaved to fit flush with a hand plane.
Pieces of Z profile aluminum were bolted to the marine ply frame panels... then bolted to the existing aluminum windscreen frames.
The plywood panels were wired together in the stitch and glue boat building technique...
The panels were then fiberglassed, taped, glassed more, sanded, sanded. and sanded.
The top was trimmed to be 3-4" outside the frame panels
A 3" wide stiffener strip was epoxied to the aft edge. This strip will also help divert rain away from the cockpit.
Then more sanding, sanding, and sanding.
Finish roll and brushed with Interlux Brightside polyurethane topside paint...
Winter was coming so I covered the project and this coming spring will add more paint and the handrails.