not really an issue

Posted by LeeG on Oct 2, 2005

you mention the sheerclamp/internal tape techniques as an issue. That issue is more of a consequence of marketing than anything. If you notice the chine joint on the Chesapeake is taped. So there must not be a structural difference between tape and wood. Most strip and composite hulls are joined at the sheer without a sheerclamp so there doesn't appear to be an advantage there. Using a pre-glued sheerclamp accomodates a construction technique so the deck doesn't have to be a specific dimension,,it's put on oversized and trimmed down. There's a kayak that's called a Putz walrus that's similar where oversized panels are put on a frame of chine stringers and trimmed down. Whatever works.

Getting a four panel hull straight with pre-glued sheer clamps puts the side panels under more tension than a similar construction without pre-glued sheerclamps. This complicates making a hull without twist compared with four panel hulls that are made up with only 4mm ply. For example the A.Hawk attaches sheer clamps AFTER the hull is glued up.

It's a surprising difference regarding truing up the hull. I made a Ch18 and a Merganser 16 (similar to Shearwater16) around the same time. With the Chesapeake you make VERY certain that the panels don't shift as it's stitched up otherwise any attempts to "untwist" it will result in one side panel shifting vertically to the other at the ends and one chine joint having a different angle near the end that's being untwisted. The consequence of that is often one veneer being sanded through providing a dark streak. But mostly the act of "untwisting" is a half solution for a problem that started with the first few wires at the other end of the kayak. With the Shearwater/Merganser it took 10seconds to "untwist" it. Likewise the issue of "flatspots" developing in the bottom hull panels is a not unheard of thing for a Chesapeake, it's a consequence of the tension presented by the pre-glued sheerclamps. Certainly a first time builder can take it out before gluing things up but often times a first time builder goes with what happens.

In Response to: Re: Pgymy vs CLC by LeeG on Oct 2, 2005

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