Old Faithful

When doing battle with the sea, you need well maintained soldiers

Considering the fact that seacocks are front line soldiers in the battle to keep water on the outside of your hull, the lack of maintenance they typically receive borders on treason. Like any equipment located out of sight in the dim recesses of the bilge, seacocks are expected to function when called to duty and generally receive little thought otherwise – until they fail. Here are some inspection and maintenance tips to help keep your seacocks ready, willing and able to join the battle.

Types of seacocks
The most common seacock styles are a tapered-plug, expanded-rubber-plug, and ball-valves. Gate valves, though sometimes used, are notorious troublemakers and not recommended for use as seacocks. Not only is the worm gear and associated guts of the  gate valve prone to corrosion and failure, it’s also possible for trash to prevent the gate from closing properly. Un-flanged ball valves screwed directly onto a through-hull are also fairly common, although this really isn’t an acceptable practice. Modern ball valve types featuring a supportive flange (like the traditional tapered-plug units) are a much better option.
Material-wise, seacocks will be of either marine grade bronze or composite construction (such as Marelon® for example).

Inspections
Seacocks should be inspected and exercised at least monthly to ensure both proper operation and to prevent any potential problems from elevating the onboard terror alert to Code Red. Start with a visual inspection of each seacock, keeping an eye out for anything unusual such as leaks, broken hose clamps, damaged or missing components (handles for example) and corrosion. If connected to the boat’s grounding system, check to make sure all connections are tight and corrosion-free for proper operation. Verify the installation of backing blocks and that each one is stable, leak-free, properly sized (surface area greater than that of the seacock flange) and in the case of wood, rot-free.
Next, check the seacock for smoothness of operation, ensuring it not only opens and closes, but can be easily reached in an emergency. It’s also important to check that the handle can be moved through its full range of operation without being blocked by equipment, cabinetry, etc. Seacocks found to be frozen or otherwise inoperative should be serviced immediately to return them to full proper working condition.
Other installation land mines to keep an eye out for include the use of PVC fittings and plastic to metal joints. Both materials have different expansion and contraction rates which can result in plastic fitting cracks or splits. Another issue to keep a lookout for are installations utilizing a short piece of pipe or hose between the seacock and through-hull, potentially introducing a failure point inside the hull that is unprotected by the valve.
If the boat is hauled, remove the hose and look through the seacock to verify operation and spot blockages. Another option is shining a flashlight into the through-hull from the outside and observing its operation while someone inside opens and closes it.
Now is also a good time to inspect all seacock hoses, making sure they are of the correct type (marine grade and approved for use on fittings below the waterline); free from damage or deterioration; and that each end is double clamped with stainless steel clamps where possible. Each hose has a limited lifespan and while replacement recommendations vary between manufacturers, 10 years is probably a prudent age for replacement of any of them.

Maintenance
While specific maintenance requirements will vary based on the type of seacocks you have installed (plug, ball, bronze, Marelon, etc.), general maintenance should include operating the seacock monthly as previously stated, as well as a good greasing at least twice a year (even for so-called “maintenance free” units).  Greasing a seacock while your boat is in the water can be accomplished following these steps:

1. Close the valve.
2. Pull the seacock hose.
3. Remove remaining water from
     the valve/tailpipe.
4. Swab a suitable waterproof
      grease onto the ball.
5. Inspect the hose for damage,
      deterioration, corroded hose
      clamps, etc., then reattach.
6. Exercise the valve four or five
      times to spread the lubricant.
Note:  Steps 4-6 can be conducted from outside the hull when hauled to lubricate the opposite side of ball and seals.

Now that you’re in tune with their needs, here are two closing thoughts on attaining true seacock Nirvana. First, it’s always a good idea to locate soft, tapered wood plugs (cones) of the appropriate size at each seacock. These plugs can be attached with light line or stowed in a portable “Damage Control” kit (along with a hammer) that should always be kept in an easily accessible location and ready for instant use.
Finally, posting a diagram showing the location of all seacocks in an easily visible location (above the chart table for example) is an excellent “knowledge is power” device, one that would come in handy during those pre-departure briefs. Now, it is to be hoped, you will never hear the question, “Where’s all that water in the bilge coming from?”