Boat U.S. - January 2008 - (Page 37) The odor problem may be caused by the presence of vegetable matter in the water, which decays during the time the water is retained in the hot water heater. It is possible that the tank itself is deteriorated or, since it is not yet leaking, that the tank’s magnesium anode has been eroded to the point where it is no longer effective. The anode is usually attached to the hot water outlet fitting of the tank and can be examined by removing the fitting. However, you mention that your boat is a 1995 model and therefore it is likely that the water heater has been in service for about 12 years. Depending on the condition of the tank, you may wish to proceed with care if you decide to inspect the anode; on occasion, removing the fitting from the tank can cause damage to the threads into which the fitting is fastened, necessitating replacement of the tank. dew is often found growing in bathrooms and particularly in shower stalls where there is poor air circulation. Cleaning with bleach kills the fungus but cannot prevent its regrowth. You can eliminate the problem in the bilge of your boat by ensuring a flow of air through the space by providing two or more air vents. Boat owners whose boats have access to shore power may install small fans to provide a forced flow of air. A solarpowered air vent can be used to good effect if a way can be found to install it where it will be exposed to sunlight and will not interfere with crew movement. Battery- or AC-powered ozone generators that restore a normal atmospheric ozone level, about 20-40 parts per billion, can also be very effective in eliminating mildew. Q: I have an 18-foot fiberglass bowrider (Scout 2005) that has an odor in the bilge. I have tried soaps and a bleach/water mixture which I sprayed in every area of the bilge that I could get at or those that drain into the bilge. The bleach mixture worked the best but the odor and black algae came back. The boat was bought used in Florida and brought to New Jersey. Do you know of anything that can eliminate this algae and odor? Paul Miller Manasquan, NJ Based on your description of the problem in the bilge area of your boat, I will assume that the bilge is enclosed and not well ventilated. I believe the problem you have noted, a malodor and a black deposit, is most likely mildew, a mold, specifically a fungus, not an algae, which is a plant that requires light to support photosynthesis. Mildew fungus spores, which are invisible to the unaided eye, are always present in the air, often at concentrations in excess of thousands per cubic foot. The fungus does not normally grow in well ventilated spaces where the normal atmospheric level of ozone, 20-40 parts per billion, is sufficient to prevent its growth. However, the ozone content of air in an enclosed space will decrease to essentially zero after an hour or two, after which the fungus will begin to grow. This is the reason that mil- A: My new MerCruiser 5.0 EFI specifies a gradual 20-hour break-in period, where the engine is only gradually exposed to higher rpm. Presumably to season or temper the cylinders. I am a fanatic when it comes to proper engine maintenance and I hope to keep this boat for many years and long hours. When I purchased my new boat, the dealer retrofitted the new motor with a sealed coolant system. The mechanic failed to tighten a clamp. As a consequence, the coolant escaped and in the first three minutes of engine life at the recommended rpm, the engine overheated and the automatic safety system kicked in and shut off the engine. The temp reading was 200 degrees at shutdown. My boat dealer has assured me no harm was done and my long-term fuel and oil efficiency will not be adversely affected. Do you agree? Something about this assurance does not make sense to me, since MerCruiser goes to some length to insist on avoiding overworking an engine in its virgin 20 hours. Is there anything I can do, other than document the incident? My concern is that any future performance problems will not be directly traceable to this incident, if in fact it caused any future problems. Bruce Tait Nova Scotia, Canada Q: walls or valves. The remainder of the engine is largely cooled by oil and would not have experienced any overheating in the operating time you report. The alarm triggered the automatic shutdown as soon as the coolant temperature exceeded the limit. I base my belief that you should see no future problem on the fact that the high sensor temperature was the result of total or near-total loss of coolant and not due to failure of the cooling system to remove heat from the engine. If it were my boat, I would accept having the engine cooling system restored to proper operating condition. I suggest that once you have satisfied the recommended 20-hour limited rpm period that you run the engine at full power for a number of five-to- 10-minute periods both to evaluate the behavior of the cooling system. Longer periods of close-to-full-power operation will be needed to fully seat the piston rings. Q: When I purchased my current boat (2003 Four Winns 240 Horizon) I was told that operating the boat with the switch in the “both” position was not recommended because it wouldn’t properly charge both batteries. The theory goes, according to my sales technician, that if you have one charged battery and one in need of charge that the alternator/voltage regulator would detect the charge of the fully charged battery and therefore would not send a charge to the weak one. Seemed reasonable to me but this seems contrary to the comments in your last column. I always run my boat on either 1 or 2 (alternating between the two on each outing) and almost never on both. This, in theory, guarantees that I’m fully charging the battery in operation (as well as ensuring it will start the motor as you mention in your article). So, more fuel for the fire! The Carrs Hingham, MA A: In my opinion it is best to start the engine on one battery to check its actual ability to provide the high starting current demand and then switch to “Both” to recharge both batteries. For more of Chuck Husick’s insights, go to BoatUS.com and look for Chuck Husick under Resource and Reference. BoatU.S. Magazine January 2008 A: Based on your report that the overheat alarm sounded within a few minutes of operation, I believe it very unlikely that any damage was done to the pistons, cylinder 37 http://www.BoatUS.com
For optimal viewing of this digital publication, please enable JavaScript and then refresh the page. If you would like to try to load the digital publication without using Flash Player detection, please click here.