|scarph - 12/1 ratio|
Pat Montalbano, the fine boat builder at Barron's Boatyard on City Island has built a new mast for my Buzzards Bay 14 - North River 2 which was dismasted in the September 2012 storm. It is a 24 foot, tapered, glued wooden box mast made of Sitka spruce. The joints types are rabbet and feathered edge scarph. The glue is West System G Flex. That glue held when I was dismasted. The wood split, not the joints.
|A guy I found on a chat room Boatdesign.net, T Cubed says: Box masts are easy. Well, conceptually, but not in practice. T Cubed has a lot of good advice. (beow) Pat set up on a solid, level surface = a 2x8 plank, right next to the re-assembled broken mast so he had a full scale model right there. Above are some shots of Pat's work:|
T Cubed's work plan: Get your work surface true and straight and draw on them marks to follow when gluing. If you use work horses get a half dozen of them and use wedges and taut string to get it all straight mark the horses (As in the mast needs to go exactly between this mark and that mark on each one).