Originally Posted by Flod
This winter I had my dufour
41 on the hard
with the deck stepped mast still on. I loosened the rig a little after hauling. When I came out to the boat this spring I noticed vibrations from the mast inside the boat. Now I realised that the beam supporting the deck just aft the mast have come loose on one side. I have two questions:
1. Do you think the vibration in the rig is the root cause?
2. How should I repair the loosened beam?
1. No, the rig vibrating shouldn't cause any parts
of a boat's primary structure to come loose. Such structures should be able to withstand HUGE forces without a second's thought. Think about the kind of loadings they get if you're out at sea when it's blowing 30kts, or even 50kts. There's LOTS of vibrations then, from the wind
in the rigging
, & on the spar itself. This along with gigantic loads due to punching through waves, along with those generated by the sails
. And the static downforce on rigs can on some boats be more than twice her displacement
... Before you hoist any sails
Also this design appears poor in both design, & execution. Especially in that it appears that it was attached with less thought to how to do it properly, than your average mirror. Meaning with just a little adhesive
between an undersized mounting pad & the overhead, with zero fasteners or tabbing.
So it's mounting strength was entirely dependent on that small surface area of glue underneath of the mounting pad at the beam's end.
2. I'd need to see lots more pics of how things fit together on this boat to even begin to offer up guesses. And get a sense of how the loads are designed to be carried.
You might talk to the builder
, as well as finding an owner's group/forum, about this. As well as hiring a good shipwright to first inspect things, & then make recommendations. Possibly having him doing the fixes as well.