Seacocks
A solution for awkward seacocks
A Damaged through-hulls can sink your boat, so don’t ignore corrosion—especially rose-colored tints under green verdigris. This could indicate dezincification. Cheap valves and skin fittings made of poor materials can break off after only a few seasons.
B If serviced regularly, quality fittings made from bronze or DZR1 (dezincification resistant brass) can last for decades. To spread any loads from moving the valve, this type has a flange bolted through the hull.
C Alternatively, it can be fixed to a backing plate attached to the hull with modern glue, or glassed in. Sealant then prevents the ingress of water. A tapered wooden bung will plug holes in an emergency, and bonding wires are needed in certain circumstances to prevent corrosion. Plastic valves are used in some metal boats for the same reason, but they can melt in a fire.
D Gate valves screw a “gate” across the water passage. If they’re corroded, the extra leverage on tall through-hull fittings can break them off. Cut them to the correct length.
E Ball valves turn the “hole in the ball” through 90 degrees to shut off the water. Flush thoroughly to avoid corrosion.
F Tapered plugs in some seacocks can be vertical or horizontal. Restore the mating surfaces in a couple of places with grinding paste and keep them well greased. The lever should move easily.
G Heat up tight pipes with a travel hairdrier that is small enough to get into the space. Do the clip “up” first to crack the crud, then release and use a pick to ease it off.
H A “bolt and blocks puller” will remove stuck through-hull fittings.
I Use a small wire brush to clean the thread and then apply penetrating oil.
J Cut and split the nut if it won’t unscrew.
K There are often notches in the fittings to lock or turn them. A flexible saw blade will cut off corroded ones. After removing the bolts, a seized plug can often be driven out with a drift.