Builders' Forum Archives
Re: Sassafras 14' ?
Posted by LeeG on Feb 13, 2005
there are a bunch made in some WoodenBoatbuilding classes,,it would be worth getting some feedback there. I'd be worried about the unglassed 4mm lap joints in the center of the hull being strong enough. According to the glassing schedule the outside is only glassed on center keel panels and not over the first lap joint. The inside is glassed on the center and adjoining panel with 6oz cloth over the lap joint ending before the second lap joint. The problem I see is on the second lap joint where there's no glass on either side,,where the hull takes an up turn at the waterline. The keel has glass on both sides, the first lap joint has glass on the inside, the second lap joint has only a thin fillet joining 4mm ply in an area where the hull widens out. If you're in a solo canoe kneeling and lean the canoe a lot of your body weight will be pressing near that second lap joint concentrating on a knee. Just as a comparision a Chesapeake kayak built with 4mm okoume has at a minimum 9oz tape on the inside and 6oz glass on the outside. The multichine hulls have 6oz cloth on both sides. Unlike a scarf joint a lap joint doesn't have as large a joining area so the wood has to be thick enough for a filleted lap to be strong enough compared to a glased butt joint. I wonder if an unglassed 4mm lap joint (where the wood is 2mm thick at the lap) is up to the task in a 14' canoe where it appears to work in the Sass12, and it definatley works in 6mm for a 16' canoe. Unlike the larger dinghies/Skerry/Chester Yawl the canoes don't have intermediate bulkheads providing hull strength,,it's all in the laps.
In Response to: Re: Sassafras 14' ? by Pete on Feb 13, 2005