70 ASK THE EXPERTS 74 GEAR 80 SEAWORTHY 87 ELECTRONICS YOUR GUIDE TO PROJECTS, SKILL-BUILDING + WHAT’S NEW PRACTICAL BOATER |
PHOTO: DAVID J. SHULER
ASK THE EXPERTS
SOLUTIONS FROM THE BoatU.S. TECH TEAM
I just read an article in the Caribbean Compass; they’re advocating aluminum
anodes as opposed to traditional zinc. What are your thoughts?
of things could cause the ECM to increase
the rpm. Superstitions aside, I think your
dealer can make the ghosts go away!
PLUGGING THE HOLES
Kenneth Klein, Crawfordville, FL
DON CASEY: I suspect aluminum-alloy anodes are in all our futures because of the environmental implications of cadmium in zinc. I’ve seen no report of switching to aluminum
resulting in damage to the underwater metals on a protected boat, but the cost of aluminum
anodes has been higher. Aluminum also works well in brackish water. If you make the switch,
all of your anodes must be aluminum. That’s a problem in many locales as local marine suppliers often don’t stock a wide selection of aluminum anodes. That will eventually change.
I installed a new fishfinder. The new transom
bracket was different than the old one so I had to
plug the old screw holes. I used Marine Tex and
inserted it with a plastic needle as far as I could,
and let it dry for two days. Is this a good way to
seal a hole below the waterline?
East Quogue, NY
I have a 2000, 50-hp Mercury Bigfoot, 4-stroke outboard. The engine starts right up. However, after
idling at the dock for a few minutes, the engine revs to 3,000 rpm and stays there all by itself! The
throttle linkage doesn’t move when this happens. It’s like the motor is haunted.
Edward Vozzella, Walpole, MA
JOHN ADEY: I have a feeling there may be a problem in the electronic control module
(ECM). The only way to diagnose the issue is to have an authorized Mercury dealer plug
into the ECM with a laptop with the Mercury service software, and watch what the engine is
doing when it revs up. An improper interpretation of the temperature sensor or any number
TOM NEALE: Marine Tex is good stuff,
but in my opinion it’s a bit brittle for that
job without doing more. To be sure of a
waterproof repair, I’d apply several layers
of fiberglass and epoxy resin over the two
holes to be sure that voids don’t develop.
This could allow water to seep inside the
transom coring, potentially causing serious
long-term damage. At this point I’d leave
the filler there, but I’d thoroughly sand the