ASK THE EXPERTS
EDITED BY TOM NEALE
ASK OUR EXPERTS Our technical editor, liveaboard and DIY guru Tom Neale, creates this column from correspondence with our
members. Read Tom’s exclusive column, On Board With Tom Neale, only at BoatUS.com/Magazine. If you have a boat problem that you
can’t solve, search our website for answers. BoatUS.com/BoatTech
Crazing and cracking
I inherited a 15-foot outboard fiberglass boat in relatively good
shape, with a newer Mercury motor. But the boat is from 1980,
so it’s starting to form hairline cracks on the hull. More concerning are some cracks forming where the transom connects with
the hull and around the motor bolts. Is it worth taking it to a
repair shop and having them restore the hull and paint it?
ALEX BLACK, STAMFORD, CT
TOM NEALE: Gelcoat cracking and crazing isn’t unusual;
many boats that age have this issue. The repair can usually be
done as a DIY project. Epoxy manufacturer West System has
many products and much advice on its website (westsystem.
com). The more serious problem, however, is cracking where
the motor is bolted on and where the
transom connects to the hull. This could
indicate very serious structural issues,
although I’m not there to inspect your
boat and so can’t say for sure. Also, if the
cracks are so bad that water has found
its way into any coring or wood support
in the transom, this could be costly and
dangerous. I wouldn’t want to use the
boat or get a repair done without a good
marine surveyor to check it over first.
Beating the heat
The impeller in my water pump shredded. I think I got all of it, but the motor
now overheats after the impeller change.
Does the pump need a rebuild?
T.N.: The pump may be ready for a
rebuild; it depends on usage and age. It’s
more likely, however, that other bits of
the impeller are embedded downstream
of the pump, thus obstructing water
flow. Generally, if it’s a raw-water pump
on an inboard, there’s likely to be pieces
of the impeller in the heat exchanger
downstream. Often the tubes there will
trap them, and if you pull the end cover
plate, you may solve the problem.
Check that plenty of water is getting to the pump in the first place.
Coincidences do happen, especially on
boats, and a clogged raw-water strainer
is easy to fix. You might try a back
flush from downstream, but you could
inadvertently flood the engine or do
other harm if you’re not familiar with
your engine’s plumbing. Have a qualified
mechanic look at that. Or you could try
a back flow of air or suction with a wet-