Plumbing

Our testers began the evaluation with a close inspection of how each unit was assembled and what materials were used in their manufacture. The test field included stainless-steel, aluminum, and mild-steel boilers. When it comes to water tanks in sailboats, stainless-steel is favored over the other two metals, so we naturally asked ourselves why the water tanks in water heaters would be any different? To answer the question, we embarked on a series of bench tests and a long-term corrosion test to see how stainless steel, aluminum, and mild steel water heater tanks handle use in a salt-laden bilge-like environment.

The physical installation of a water heater may seem pretty straightforward, but the devil is indeed in the details. It starts prior to purchase with a search for adequate space thats relatively near the engine and vertically as low as possible. Next is bonding in a well-reinforced surface to mount the water heater onto. The empty tanks are relatively light, but if you add 45 to 88 pounds of water, you can see why a sound support base is important in a rough seaway.

It is surprising to see equipment with no moving parts carry such an array of safety warnings. But any time water and higher-voltage AC electricity are mixed, there are details worth thinking about. The risk of shock can be lessened through a firm commitment to three-conductor wiring that follows the American Boat and Yacht Councils guidelines. This includes maintaining the continuity of the green grounding that links the boiler and metal housing to the boats ground. Strict adherence to high-quality crimp connectors, appropriate wire gauge, and care in keeping the neutral and hot wires consistent with the vessels and docks power supply are paramount.

In the December issue PS evaluates four water heaters that are new or have been significantly updated since our last test in 1999. Water heaters are one of those silent heroes that rank high on the list of comforts on a boat. The test field included the Kuuma 11842, an 11-gallon tank; the stainless-steel Quick Nautique BX2012; Raritans 1706; and the 30-liter Compact from Sigmar Marine. Testers considered each heaters efficiency (using AC and engine-driven power), power consumption, construction quality, and ability to keep hot water hot.

General-purpose, relatively inexpensive hose clamps are all over most boats, but there are some applications where using a higher quality, corrosion resistant clamp is critical-such as engine hoses and through-hulls. Most quality clamps are stamped stainless steel, but there are many grades of steel, and making an alloy stainless and corrosion resistant is complicated and costly. You start with iron, which rusts easily, and through multiple processes, you add proportions of elements such as nickel, manganese, molybdenum, and chromium. Different percentages of these elements will improve the desired strength, hardness, and flexibility, as well as corrosion resistance, of the steel.

Winterizing agents should never be used in freshwater tanks or hot-water tanks. Doing so will greatly increase the chances of biological growth, which can result in foul-smelling, bad-tasting water. If your boats water system does not have bypass fittings that allow you to add glycol to waterlines, install them. The addition of a few simple fittings can reduce the annual process from hours to minutes for the cost of a few jugs of glycol.

Protecting marine water systems from freeze damage is a deceptively simple goal. The terminology and various product claims can be confusing, and what seems like a good common-sense decision can lead to trouble. We tend to think that all water systems are the same; that boats as well as RVs can be protected by the same pink antifreeze without any further thought. However, many of the problems we associate with age, or normal wear and tear-stiff impellers, cracked pipes, ruined joker valves, and foul-tasting tap water-can often be attributed to errors during winterization.

When contributor Drew Frye commissioned his familys PDQ 32 catamaran six years ago, his daughter asked, What are these pink lumps in the sink, Dad? The toilet bowl was even more spectacular, a science project in a dozen hues of pink, green, yellow, and black. The boat had been winterized for some time, down in south Chesapeake Bay, where winters are mild and many boaters and don't take freezing seriously.

When it comes to onboard water tanks, we prefer stainless, fiberglass, and even roto-molded tanks (in that order) to aluminum ones. Aluminum tanks tend to pit and corrode over time, often needing to be replaced. The insides of the two 60-gallon aluminum water tanks in our 30-year-old Valiant 40 were more like a nasty moonscape than a drinking source. Their surfaces were pitted and rusted from what looked like a reaction to long-time use of chlorine.

Ever find a bug doing the backstroke in your water tank? We have. Would you leave a glass of water sitting uncovered for weeks and then come back to it? Of course not, but many builders either lead the hose to a mushroom-type through-hull fitting, or terminate it inside the cabin, with nothing to keep the ubiquitous critters from seeking shelter, fresh water, or a nesting site.