Persistence

Persistence pays off in the end, if you don't give up too early.  This is one of those cases...

Remember this post?  In it I talked about using aluminum tape to seal the top of the mast boot to the mast proper...

When it was new

Backspacing at least 10 years, we have been dealing with intermittent leaks at the mast partners.  Each thing that we have done has improved the situation... but the leaks, tho diminishing in quantity and in frequency, have persisted.  Replacing the mast boot, resealing the deck ring, and finally replacing the deck ring altogether with a composite material that won't absorb moisture and consequently change shape and break the seal have all helped.  But even after all this, there was still the occasional drip coming down the mast in heavy rain and wind. (OK, maybe I am a little anal retentive here...)

Looking up from inside revealed that the water was not coming in at deck level - hooray!  That leak is stopped!  Instead it was coming from higher up.  The only place where it could be originating was at the seal between the top of the mast boot and the mast.  However, a brief inspection (because it was raining) did not disclose any flaw there.

But.  The water simply had to be coming in there.  So I pulled the hose clamp off to get a closer look at things.  Lo and behold, the aluminum tape was just plain gone under the hose clamp!  Galvanic corrosion between the stainless in the hose clamp and the aluminum tape ate the tape, and created an opening for rain to find its way in. 

There are two lessons here.  First, galvanic corrosion is evil.  And just as importantly, frequently corrosion is hidden.  Both very much worth remembering.

The fix was easy:  remove the offending hose clamp (it really was overkill anyway - the aluminum tape is more than sufficient to hold the boot up), and apply a fresh layer of aluminum tape.

Improved Deck Ring

Eolian's deck ring was not molded into the deck because the Downeast 45 was sold with three different rigs: sloop, ketch (Eolian), and schooner.  Because each of these rigs required a different mainmast location, it was impractical to make three different deck molds.  Instead, the deck ring was fabricated from two pieces of teak and bolted to the deck in the appropriate position for each rig.  

But there has been a persistent deck leak originating between the deck ring and the deck proper.  Various attempts to seal the deck ring without removing it had been problematic, working for a while and then the leaks returned.  Eventually, I pulled the ring up and resealed it with butyl rubber. And then there was the little problem at the joint between the two pieces of wood where apparently a piece broke off of the cross-grain at the end, leaving a gap which was filled with a glob of caulk.  In the reseal, I at least used a small piece of teak for the bulk of the required filler. 

But even this was not a complete success.  I speculate that the wood would grow and shrink with moisture, working the seal.  The answer was obvious:  replace the wood with something which was impervious to moisture.  I used Trex composite decking, obtained as a scrap from a neighbor's deck replacement project.  I carefully traced the outline of the wood pieces onto a piece of paper, including the holes for the mounting bolts, took this paper home and relayed the outlines of the two pieces onto the Trex and bandsawed them out.

 

 

I made the outside edges a little rounder than the teak versions because the hose clamp that holds the mast boot to the ring did not apply sufficient pressure to  the straight sides of the original ring, allowing wind to blow rain up under the boot - thus the foam tape applied to the outer surface. 

 

 

(The mast wedges bear on the deck edge, not the deck ring)

In the final installation (also bedded in butyl rubber), I also applied foam tape to the edge, just in case my "rounding out" the straight edges was not quite sufficient to make a tight seal.

This should last forever.