Salt and water conspire to reduce our boats, our pride and joys, to pitted and unreliable money pits. Weve investigated corrosion of wiring (see PS July 2010 online), gasoline (see PS August 2012 online), diesel (see PS August 2013 online), and winterizing fluids (see PS September 2014 online), uncovering additives and practices that dramatically reduce deterioration and increase reliability. Engine cooling systems have similar vulnerabilities, and fortunately for us, the automotive engine manufacturers have invested millions in finding those solutions. However, the marketing materials don't always make the differences clear, and its hard to know which product is the best for your engine.
Samples were tested for corrosion protection following the ASTM D1384 Corrosion in Glassware method (www.astm.org). Samples were diluted to 33-percent glycol, dosed with ASTM synthetic corrosive water (similar to 2-percent seawater), continuously aerated, and heated to 190 degrees for two weeks. As a laboratory control, a reference coolant (ASTM D 3585) was also exposed to provide a baseline.
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.
We tested each product for glycol content using a refractometer and either the ethylene glycol or propylene glycol scale, as appropriate. In the case of Camcos Arctic Ban and Sudburys Winter Stor, some portion of the freeze protection is provided by ethanol, and such mixtures cannot be easily evaluated by any field method (test tape, gravity, refractometer) unless the exact proportion is known, which we find troublesome.
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.
What matters most, our testing confirms, is not so much which brand of pink stuff you choose, but how you use it. Even the best product, mixed with too much water left in the line, results in a blend with unknown and perhaps unsatisfactory performance. While this may not be critical in North Carolina, sailors in Wisconsin need to get it right.
Summers warm breezes and lazy weekends have arrived, so PS testers have put together a lineup of cool toys and tools for the dog days. Tower Adventurer Inflatable Standup Paddleboard: Inflatable SUPs are sprouting up everywhere on the Internet; many boards are identical, made by different brands at the same factories in China. Quality varies. Generally, boards 6 inches or thicker offer better stiffness and stability, making them easier to ride.
Capt. Bernardo Herzer has been converting small engines from conventional fuels to propane since he was a teenager. In 2012, he introduced his first propane outboards, 2.5 horsepower, 5-horsepower, and 9.9-horsepower models. Practical Sailor recently tested the 5-hp Lehr LP 5.0, a water-cooled four-stroke with an electric ignition-no priming or choke required. It operates at 4,000 to 4,500 rpm at wide open throttle, and the 49.6-pound, short-shaft model pushed our 120-pound test boat at 11-12 knots. The engine can be fueled using a 16.4-ounce propane twist-on bottle like those used with camping stoves or a 5-gallon, 20-pound remote propane tank.
Every day, as the temperature rises and falls, gases inside your fuel tank expand and contract. The emissions released during this diurnal breathing have raised concerns at the U.S. Environmental Protection Agency, and in July 2011, the agency mandated passive carbon canister filters on all installed gasoline-tank vent lines to collect fuel evaporation emissions. While older boats are not required to retrofit, we wondered how such a filter would affect fuel quality and engine performance-and whether carbon is the most effective filter media-so we launched tests using E10, gasoline, and diesel to find out.
Practical Sailor’s original goal with this evaluation was to run a long-term test of fuel additives. Instead of adding heat or oxygen or excessive corrosive materials, we would substitute time. After six months of testing additives in E-10 gasoline, we found no measurable corrosion, so we elected to add a small amount of seawater and compare fuel samples after one month. The results were surprising to even our testers. The additives we tested were: Hammonds’ Biobor Ethanol Buster, CRC’s Phase Guard 4, Mercury Marine’s Quickstor, PRI-G, Sea Foam Engine Treatment, Sta-bil Ethanol, Star Tron Ethanol, and ValvTect Ethanol.
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We think the best bet is the modern keel/centerboard. Unlike centerboards of 20 years ago, the new ones are very efficient going to windward with the boards down and not all that bad with the boards partially raised or withdrawn into a stub keel.