One of the teak faced cockpit seats under construction. Seat has a solid
teak frame with sandwich of 3/8 inch birch ply and 1/8 inch ply for base.
(There is gap between the layers with fir stringer strips, like a wing construction.)
Top is covered with 1/4" teak. The grooves were then routed out uniformly to
7/32 inch wide and later filled with polysulfide seam caulk.

Cockpit after mostly complete after painting topsides.
The "pourable" lifecaulk polysulfide seam sealer was very messy to work with.