Monday, February 20, 2006

DB trunk mockup

Continuing on with the construction of the center seat/daggerboard trunk assembly: After 24 hours of curing, the spacers were trimmed, and the mating edges of the daggerboard trunk were sanded flush. Then came the initial fitting and masking for the filleting of the whole unit.

Essentially, the daggerboard trunk is a hole in the bottom of the boat. Since the hole is sealed to a collar the rises from the hole higher than water level, buoyancy is not threatened. But this is perhaps one of the more critical steps in building a Passagemaker dinghy. The daggerboard trunk contains many joints, all of which must be absolutely waterproof. Also, since this is the slot that the daggerboard passes through, it must be plumb, square, and aligned with the centerline of the boat. So tonight was a trial run in assembling the trunk proper, the midships seat, and the center bulkhead all into one unit. Being careful to keep checking for squareness and plumb, I marked the final position of all the parts. Then, 1-1/4" bronze screws were countersunk through the bulkhead into the aft spacer of the trunk. When everything was finally aligned, the borders of the future epoxy fillets were masked with tape, to give clean edges. All is ready for the permanent epoxying of this unit. Total hours 52.25.


Blogger S/V Mistral said...

I thought I had made a perfectly neat bond with my centerboard trunk when I built a Lake Union Skiff a few years ago as part of a Center for Wooden Boats family boatbuilding workshop. See :
But lo it has the smallest of leaks that, while negligible, is still annoying. You can try resealing such holes by painting on epoxy in and out but it's best to get it right the first time. My thinking is I tried to make the seal neat but ended up skimping on the epoxy as a result. Minimizing stresses will help too. The trunk can essentially act like a lever to undo its seal at the base so it needs to be very stable.

3:09 PM  

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