Inspection of a Used Sailboat 6: Plumbing and Electrical System

Plumbing

THE EASIEST WAY TO SUNK A SAILBOAT is to neglect the through-hulls and all the other components involved in allowing water in or debris out. These installations are made up of parts that constantly degrade, but many owners seem to forget about them: according to a 2014 BoatUS study, through-hull failures are by far the leading cause of recreational boat sinkings in the U.S.

Thru-hulls

cambiar pasacasco — ▌ISO 9093 standards recommend changing valves and thru-hulls every five years.

Valves and through-hulls may look good on the outside but suffer from hidden defects

When visiting a sailboat, it is not unusual to find owners who tell us how much care they have taken of the hull and engine, but who apparently have not done the same with the valves and through-hulls, perhaps trusting their good appearance.

And here lies the danger. Although the signs of corrosion are not obvious, it is very important to note that all these parts can have a good external appearance but suffer from hidden defects. The through-hulls tend to deteriorate on their inner, non-visible face, and it is common for the valve’s closing hemisphere, even if it is in good appearance, to have calcium and snail incrustations.

Based on this, some people recommend replacing the valves and through-hulls every 5 years. And they add that the entire set should be replaced, not just one of the parts. The truth is that such a categorical statement cannot be made, since everything depends on the material of the through-hulls, the marine environment in which the sailboat operates and the regular maintenance that is carried out.

Good quality bronze or brass thru-hulls can last well over 5 years if well maintained and free of corrosion. However, components made of weaker alloys or plastics can deteriorate more quickly.
Thru-hulls made of plastic composites (such as Marelon) are generally more resistant to corrosion and do not need to be replaced as frequently as metal ones.

In any case, if a valve or through-hull fails and breaks, the risk of sinking is real. So, when we carry out our inspection, we will have to check all the through-hulls, which we will have located during the inspection of the hull in the dry dock. Inside, these parts are often hidden in hard-to-reach places, such as inside a locker under a pile of equipment or behind, how funny, a toilet. Let us not be daunted and do not overlook checking their degree of corrosion, during which we may have to clean their surfaces of verdigris (on bronze or brass parts), salt deposits or dirt from the bilge.

depósito aguas negras — ▌Location of shipwrecks in the United States in 2014 | Source: BoatUs

Freshwater and blackwater tanks

The plumbing on larger boats can be quite complicated. So, in addition to the above, we will also need to check the freshwater and blackwater tanks and the condition of the various pipes, clamps, shut-off valves, valves and electric or manual pumps in the system. We will likely find that the freshwater tank needs a good cleaning and that some pipes and clamps need replacing.

Bathroom

Regarding the bathroom, we are interested in knowing if the boat is equipped with a holding tank for black water separate from the toilet or a portable toilet, which is a good option on small boats or when the boats will not be used much.

In the case of the holding tank, we will make sure that it discharges outside and that the pipe is not clogged. Unless it is relatively new, we can assume that the rubber valve on the toilet will need to be replaced (it has to be done every two or three years, they sell maintenance kits at reasonable prices). The same can be said for the large pipe that connects the tank to the toilet.

No doubt, these jobs are not pleasant, but they help to ensure that the boat does not have any odor problems.

Electrical system

DETERMINING WHETHER THE 12 VOLT ELECTRICAL SYSTEM is suitable and in good condition is relatively easy on older boats: no, it is not sufficient and it is almost certainly not in good condition.

Today, boats are often equipped with all kinds of electronic equipment and electrical appliances. Add to that the fact that most sailboats built in the 1970s and early 1980s had a bare-bones electrical system at the time. So, unless the boat has been refurbished, we can assume that this work will be ours to do, something that can take a season or two.

Another problem is that previous owners may have made all kinds of additions and splices to existing circuits, and figuring out what is what can be a real puzzle for anyone with only a basic understanding of the subject.

In the meantime, what we can do is check the system for anything more obvious, such as frayed cables, sulphated battery terminals or electrical panels with exposed backs.

This is a long story, really. If you need to know more, check out our Complete Tutorial on Renewing the Electrical Installation of a Sailboat or Motorboat, where you will find comprehensive information on the 12V and 220V electrical systems of a boat, which will also help you judge the condition of the installation of a sailboat you are thinking of purchasing.

Batteries

Batteries have a limited life expectancy: a poorly maintained battery will not last long, and a lead acid battery with 3 or 4 years of service behind it will be close to retirement even if it has been well treated. Also, as the laws of misfortune dictate, their condition will only become evident when we start using them and discover that they discharge very quickly. So, how can we be on the safe side? In addition to asking the seller, which is always a good idea, we will check the date of manufacture of the battery and, if we are talking about lead-acid batteries and we have a hydrometer, we will see if the voltage of any of the cells is substantially lower than that of the rest, a sign that the battery needs to be replaced. We will also examine whether they are clean, whether each cell has the correct level of liquid and whether they are free of corrosion.

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