Compared to other forms of boatbuilding skin-on-frame is significantly faster, easier, and less expensive, so much so that it can feel like cheating at times. The big caveat is that there are formidable design challenges owing to the unpredictability of the materials.
Unless you simply overpower the problem with extensive bracing, lamination, or oversized scantlings, a skinboat needs to be balanced with the tension of the frame and the tension of the skin opposing each other while at the same time being balanced in strength as well. The problem is that every wood change, cloth change, and scale change disturbs this balance and the only way to learn what really works and will keep working a decade later is through lots of trial and error.
The latest boat is a good example. I was looking to learn what effect a really heavy skin would have so I sewed on a 12 oz nylon covering. This used to be a fantastic cloth that you could sew on bone dry and even then if you sewed it too tight it would eventually crush the frame. Fast forward 10 years, this is now one of the worst skins available from this supplier. Soaking wet I could barely stretch it an inch and the physical force applied overtensioned the keel line. When all was finished I ended up with a skin that is too loose around the boat and therefore not holding this boat open necessitating a thwart, and too tight longitudinally stealing all my rocker. It’s still absolutely a good boat (and tough) but not exhibiting the balanced tension I’m looking for. My personal goal is that when you take all the bracing out of a skinboat it holds its shape. It’s not easy to do.
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