Anatomy of a Water Damaged Deck Part II – Repairing and Sealing Minor Damage

21 Jan

In this continuation of our examination of cored deck saturation I’ll be taking about dehydration and perspiration. Which is to say I’ll explain how we sweated gallons while drying out and repairing some minor areas of damaged deck in the ‘ideal’ situation of a New Orleans summertime!

If you didn’t read it before it might be worth jumping back to my previous post Anatomy of a Water Damaged Deck which sets the stage for our repairs on the leaky decks of my 37-year-old boat. Our work roughly fell into three categories: sealing deck fasteners which showed minimal or no leaking, just to be safe (covered in this post), a single major repair patch (check back for this one), and areas where the core was rotted around a fitting but damage didn’t seem widespread. The last case was the most common but fortunately quite an easy fix. Or at least what we did to them was quite easy- whether this was a real fix or not only time will tell!

Here’s a prime example of this type of damage. Two vents of the type you might find on a dorade box were installed by someone in the deck just aft of the cockpit, I suppose as some sort of engine vent. Unfortunately due to a very poor install they functioned instead as twin deck-core destroyers.

 The hole for the starboard vent.
I dug out rotten wood all around the hole (which 
the fitting wasn’t even close to centered on as 
you can see from where this screw hole ended up!
After a few minutes with a screwdriver it looked like
this all around.

With this sort of damage where water is in the core but the truly rotten bits don’t extend far you have a couple of options. The most thorough is to cut off the top skin, replace the core and epoxy the old skin back on, a very time-consuming task. I was forced to do this in one place but didn’t relish doing it all over the damn boat! Luckily, there is another way which involves simply drying out the core and then isolating it from the hole so that more water can’t get in. Various methods are championed for this task ranging from drilling umpteen small holes in the saturated area to let moisture out to simply injecting or pouring in some sort of miracle product which effortlessly dries things out (unsurprisingly these various miracle cures do not seem to have a high rate of user success regardless of manufacturer claims).

In keeping with our philosophy of doing whatever is needed to get this old boat sailing again without rebuilding the entire thing in the process we decided on a repair somewhere between do-nothing and perfect. We simply dug out any wood that was rotten enough to come easily and let the rest dry for a few days. Fortunately we were aided by long stretches of 100-degree-plus weather and virtually no rain. I expect without this weather ‘boon’ we would have had to engage in more extreme methods of deck dehydration but everything seemed pretty dry after a week or so of this heat.

Once things seemed dry enough we moved on to the next step – filling voids where we had pulled out rotten wood and isolating the core so that no more water could get in. The best material for this task is thickened epoxy resin. We used West System epoxy with their high-density structural filler. To fill voids we injected the resin like so:

Sometimes careful balance is required!

The idea is to get absolutely the maximum possible amount in there as you really don’t want any voids in your deck. Once the epoxy is squeezing out all around simply smooth it and wipe off the excess. Be sure to tape the underside of the deck so your epoxy doesn’t dribble all over the cabinsides.

Viola! If water ever gets back in, it certainly won’t 
be through this fitting.

In the end we found these deck repairs surprisingly easy but we were greatly aided by extraordinary luck with the weather and had a somewhat slapdash way of doing things. Nonetheless, I’m reasonably confident these repairs will be just fine and they saved us many day’s labor if we had instead cut open all these areas of deck.

Now for comparison here’s a diesel fill fitting which was installed by the builder:

 It may be grimy but this bedding has done its job.
Many years later the pipe coming off the fitting is badly
rusted but the deck core is bone dry.
Oh if only the aftermarket fittings on my boat had been installed with the same care!

This article was syndicated from Safe At Harbour But Meant For The Sea: DIY Sailing with Paul Calder


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