Most all boats have some sort of "core" in the decks. Whether it's balsa, plywood or some of the foam cores all can eventually absorb water from a leaking deck penetration. A leaking deck, especially with wood cores, can lead to core rot and eventually delamination of the deck and loss of structural rigidity. Sailboats especially can have hundreds of holes drilled into the deck for cleats, stanchions, blocks, winches, genoa tracks or many other mechanically fastened and through bolted or screwed items.
Unfortunately most builders do not take the time, nor have the patience, to protect the core from moisture. Most all builders also fall short in their bedding techniques, choosing in favor of time over lost profit. The "can't be seen, must not be there" mentality certainly rings true in the category of deck hardware installations.
The re-bedding of deck hardware is a time consuming task but one that can save your five, six or seven figure vessel from loosing 25% to 50% of it's market value due to saturated and rotted decks.
There is no method better than "potting" the holes with thickened epoxy to prevent core damage if you have core where hardware passes through. This job is easy but time consuming. Once done correctly you will never have to worry about water getting into your core again.
These are the epoxy products I use to "pot" deck holes. I generally use System Three Epoxy products but for this I used West System because its very easy to find and use. I use a #205 hardener #105 resin & Colloidal Silica or "Cabosil" as the filler or thickening agent. In order to inject the resin into the holes I use the West System syringes.
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