Preview: Topside Seams Show? Consider Splining

April 13, 2022

Avatar Maynard Bray

LOAFER is one of the lovely Herreshoff 12-1/2 footers (so named for their waterline length) and was built in 1936. Although her freshly-painted topsides looked flawless each year on launching day, it wasn’t long before her caulked-and-puttied seams began to show.  To cure this unacceptable distraction, Eric Dow carefully routed out each seam to half the plank thickness and glued in a cedar spline. He’s done this before and it’s worked. For ten years the splined seams of an identical boat have remained invisible—even though that boat’s topsides were dark blue instead of white. However—and this surely has to be considered—neither of these boats are allowed to dry out much while they’re ashore. They’re housed inside damp sheds where there’s no sun and wind to excessively shrink the planking.

This spring when I visited Eric’s shop and saw LOAFER’s starboard side so nicely splined, sanded, and ready for paint and the port side about to receive the same treatment, I grabbed the opportunity to share his procedure with OCH members feeling that it might be a solution for some of their boat’s topsides.


This is LOAFER with her splined starboard topside already for painting.


Eric’s first move after stripping the planking of paint is to nail on a batten to guide the router. He positions it so the routr bit will bisect the seam. 

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