Quote:
Originally Posted by captianjuan
Hey all,
so I am just about to purchase a boat and discovered rot in the base of the deck stepped mizzen mast. I love the boat. But I don't know what's repairable and what's safe with regards to a wood mast. its soft from just above the 4" high stainless sleeve to about 1.5 feet up. its a sitka spruce, appears to be laminated with a wire tunnel. I was thinking of cutting it and laminating some plates and building a metal sleeve with bolts, possibly doing it in place by drilling a hole in good wood and lifting its weight off the deck and then cut out and rebuild a new base. Im in Hawaii now and its not cool to do shipyard here. im an experienced sailor/marine engineer. I have crossed oceans before. please don't lecture me about the dangers. im looking for ideas about a solid patch that can get me to mexico and then how permanent and worthwhile it would be to to a full repair there vs an aluminum swap. im thinking of making a laminated sleeve or a metal sleeve and sail it to mexico for shipyard. thanks guys.
fair seas,
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Captainjuan this is a simple repair.
The vast majority of force for a stayed spar, particularly at the base, is pure compression. Cut out the soft wood, and
epoxy in what we used to call a "Dutchman" or wood patch. In this case it could be any dry wood you can get, of the same thickness, and maintain grain orientation. Ideally you would scarf the ends for a proper repair. But with three good sides, and since it's so close to the base, scarfing isn't absolutely necessary, square butt joints will
work. Wrap it in biaxial glass if you're concerned about not scarfing.
And yes, if you can extend the sides of the metal base up above the rot and put a number of through bolts clear through you can leave the rot for Mexico.
With a copy of Skene's Yacht Design or the
Internet you can calculate the compressive force on the mast and know how many bolts are needed.
You could also coble together a repair and do the trip without raising any sail on that spar. That would put very little strain on it.
I would really make sure you are correct about the extent of the rot.
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