Hatch Latches

We are going to file this under the category “Nobody’s Perfect,” or maybe even “What Were They Thinking?” As a boatbuilding company, Amel is famous for thinking “outside the box” in boat design and construction.  Almost all the time they ended up doing something better. Every once in a while, however, they got a bit too far outside the box. This is about one of those times

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The deck hatches on Harmonie are held down by these clever swing bolts and hand screws. Several of them were bleeding rust onto the deck. I figured that the rust was from poor quality metal in the screws, and had not really prioritized it any higher than a strictly cosmetic project. We finally got tired of the ugly rust stains and set out to clean it up and make it look once again properly “yachty”.

It turned out there was a significantly bigger reason than cheap hardware for these rusty screws and cracked gelcoat…

This was one of Amel’s “different” ideas that, honestly, did not turn out so well.  Under the solid fiberglass deck surface, they glassed in a small block of what the marketing people called “ironwood.”  A not-so-precise term that is used for many different types of unusually hard, usually tropical, woods.  They then screwed into this with standard thread M5x0.8 machine screws.  Kind of an odd choice, but it worked–when things were new.  After 20 years, however…

Over time, water found its way into the wood, and that is never a good thing.  The wood they used might have been rot resistant, but it certainly was not rot proof.  Every one of ours were bad.  Some were so bad Karen just pulled the screws straight out by hand.  We drilled some over sized holes in the top of the deck where the screws went in and extracted what was left of the wood out…

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Yes, all of that rotten, punky, soaking wet, fibrous yuckiness was pulled out of those four screw holes with a pair of tweezers leaving roughly a 2 inch square hollow under the deck surface.  A very tedious job, repeated for each of the 10 hold-downs around the deck.  It took Karen the better part of two long days.  The good news is that this wood is isolated from the balsa core of the main deck, so the problem with water intrusion is very localized.

The resulting gap where the wood used to be was then filled with West System G/Flex 650 epoxy heavily filled with high density 404 filler, the way it really should have been in the first place.

West System G/flex 650 Epoxy

I like this stuff for this kind of work because it is much “tougher” and less brittle than “regular” epoxy. I don’t use it for everything, by any means, but when you end up with the final result being mostly cured epoxy, the extra mechanical strength of this material is worth it. As a bonus, the 1:1 mixing ratio means a little can be mixed quickly and easily.

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Ahhh… that’s better. The cavity where the wood had rotted filled with cured epoxy resin.

After the epoxy cured, we drilled pilot holes and used #6 self tapping screws to reattach the hold-downs.  No leaks possible.  Nothing to rot–ever.

If at any point we decide the self tapping screws are not sufficiently strong, we can easily upgrade to through bolts without compromise to the integrity of the deck.  There are not a great number of places on this boat where I can with total honestly say, “Better than new,” but this is one for sure.

 

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