Attaching the bottom stringer
The bottom stringer will enable two benefits.
Act as a base for the first rail strip, therefore enable an easy and precise alignment of the rail strips.
Increase the bottom rail thickness and therefore enable us to shape the rail without reducing the structure strength.
Due to the required thickness and the curve needed to apply. We will laminate two wood strips for this stringer.
The easiest way to attach the first strip is by using CA glue (super glue) with accelerator (optional).
Glue the first stringer strip to the bottom notch of each rib except the last rib (at the nose)
Once both side are attached, band the strips to the end of the spine nose using a spring clamp, super glue or mask-tape.
Glue the stringer to the last ribs (8).
At the tail let the strip follow the outline curve of the rail.
Glue the second stringer strip using PU glue (polyurethane)
Once the glue is cured, clean all excess glue and sand the side of the ribs using a sanding board. The Paulownia rib frames should be flashed with the plywood.
Planking the rails strips
Place the first strip to the bottom stringer. The strip should have contact with all the ribs. Mark the location on the stringer. Put glue on the stringer and on the ribs. Use spring claps or mask-tape to attach the first strip
You should band the first rail strip to the end of the spine nose. This will allow a natural curve between the last two ribs.
Use spring clamps or mask-tape to attach the rails strips above the first strip using carpenter or PU glue. The strips should pass the edge of the top stringer notch.
Once all the rail strips are attached. Use a hand saw to cut the rails strips before the first ribs (tail) and after the last rib (nose)
Trim/sand the rail to be flashed with the top stringer notch, using a block plane, a sanding board or a left over wood strip wrap with a 40 grit sand paper.
Attaching the Top stringer
Using clamps or mask-tape attach the top stringer strips to the top stringer notch. It is easier to it do strip by strip.
Trim/sand the bottom stringer to the outer edge of the first rail strip.
Trim/sand the top stringer diagonally. From the top inner edge of the stringer to where it interconnect with the upper rib strip.
Installing the nose and tail blocks
Use Polyurethane glue to connect the tail and nose blocks.
Align the tail block to rib 1 and the spine, apply glue and hold it till the glue is dry using spring clamps.
Before attaching the nose block, cut the nose to accommodate the nose block slot (8cm from rib 8).
Align the nose block to rib 8 and the spin, apply glue and hold it till the glue is dry using spring clamps.
Using a scrapper remove the access glue (once the glue is dry).