[Rhodes22-list] Repair of Spider Cracks at Mast Step Tabernacle

[ROGER PIHLAJA]

Chris,

Many years ago, I added a halyard organizer under the mast tabernacle.  I used longer screws to compensate for the additional thickness of the halyard organizer and I bedded them in epoxy.  I also epoxied the halyard organizer to the mast step.  Yes, I know Stan does not recommend this.  But, I felt the issues of water infiltration and rot were more important than somewhat more damage to the mast step/cabin roof if something goes crooked during mast stepping/unstopping.  I am willing to accept the possibility of more damage.  Either way, your day of sailing would be over whether the mast tabernacle just rips loose or you take a chunk of mast step/cabin roof with it.  In theory, the forces on the mast tabernacle during stepping/unstepping are just shear.  But, there are many potential variables.  Is the boat on level ground?  Is it windy?  Did one of the backstays get fouled on the outboard motor on the way up, etc?  Any of these factors alone or in combination can add significant tension forces on the screws.

My issue with the butyl tape is that it is subjected to compression when the mast is stepped and then you are hoping it springs back when the mast is unstepped.  How would you inspect the watertight integrity of the seal without removing the mast tabernacle?  If you have unseen rot, your first indication might be when the mast tabernacle rips loose during an otherwise normal mast stepping/unstopping.  No thanks, I’d rather accept the risk of more damage if I screw up during a mast stepping/unstepping.

Knowing the potential for damage helps keep the mind focused during this critical operation!  If it was idiot proof, it would be as much fun.

Roger Pihlaja
S/V Dynamic Equilibrium

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From: Chris on LBI<mailto:cknell at vt.edu>
Sent: Tuesday, July 28, 2020 12:34 PM
To: rhodes22-list at rhodes22.org<mailto:rhodes22-list at rhodes22.org>
Subject: Re: [Rhodes22-list] Repair of Spider Cracks at Mast Step Tabernacle

Great points that I had not considered (poor end grain holding ability and
end grain rot). I am a novice when it comes to this sort of boat
maintenance. The feedback raises a few questions for me. First question: If
the mast is stepped and un-stepped properly, it would seem that the force
acting on the screws should always be sheer force, not axial pull force,
right? Second question: Don't I want to make sure that absolutely no water
gets past the head of the screw and under the fiberglass to the core? I
presume that when a new boat is manufactured, the screws are sealed
sufficiently to prevent water infiltration to the wood core. Would the butyl
tape accomplish this? Should examination of the seal around these screws be
a routine part of a springtime inspection of the boat?



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