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Solved problems · Deck · Crew answer

How do I stop a stanchion or deck fitting from leaking?

Drips under stanchions, cleats and tracks usually mean the bedding has failed. Rebedding with a countersunk hole and butyl tape stops the leak and protects the deck core.

Symptom

Water drips inside the boat below a stanchion base, cleat, track or other deck fitting, often after rain or a wet sail, and the headliner or wood below may be stained.

Likely cause

Deck fittings move under load, and over years the sealant under them hardens, cracks or loses adhesion. Water then runs down the bolts. In a cored deck it can soak into the core and rot or delaminate it, which is why small leaks matter.

Stop now if

The deck is soft or spongy around the fitting, the fitting moves, or the leaking hardware carries a big load such as a chainplate or lifeline gate. Don't rely on it, and get a surveyor or rigger to check the deck and backing before sailing.

The fix, in short

  1. Find the real leak. Run water from a hose over the fitting while someone watches inside. Water can travel along the deck before it drips, so test one fitting at a time.

  2. Remove the fitting. Back off the nuts from below and lift the fitting off. Clean old sealant from the fitting and deck with a plastic scraper and a solvent that suits the gelcoat.

  3. Check the core. Probe the hole. Wet or soft core should be dug out and the hole filled with thickened epoxy, then redrilled, so the core is sealed from water.

  4. Countersink the holes slightly. A slight countersink at the top of each hole gives the bedding somewhere to sit and seal around the bolt.

  5. Bed with butyl tape. Roll butyl tape around each bolt under the head and lay it on the fitting's base. Tighten gradually over a day or two, holding the bolt and turning the nut from below so the tape is compressed, not sheared.

  6. Use backing plates. Make sure loaded fittings have proper backing plates or large washers below.

Written by Sailor Cruiser crew. General guidance, not an inspection of your boat.

Equipment involved

  • Deck hardware: Stanchion bases, cleats, tracks, padeyes, through-bolts, backing plates and cored deck

Related guides

Sources

Background reading we checked while writing this answer. The wording above is our own.

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