Yes, they ALL do.
The
hull of the O'Day 40 (1985 - ‘89) is a cored composite using ¾-inch end-grain balsa, polyester resin and biaxial fibreglass cloth. Decks are also composite constructed with balsa and
plywood core, and structural support is provided by a combination of fibreglass liners,
plywood bulkheads and various longitudinal and athwartships supports. Hull and
deck connection is lapped, sealed and bolted and then sealed /w fibreglass from the inside.
Generally the quality of construction, fit and finish is typical of
entry-level (price point) boats of the 1980s.
The 40 was based on the O'DAY 39/SUNFIZZ 39 by Briand, with modifications by Ray Hunt.