A buddy told me that after leaving my boat out of the water all winter, I should
“reactivate” the bottom paint by using a scrubby, or light sandpaper, to expose
its antifouling capabilities again. Does bottom paint go dormant when it’s out of
the water too long? Ken Baker
BETH LEONARD: The answer depends on whether your bottom paint is ablative (soft)
or hard. The copper in a copolymer ablative paint is not exposed to air but is locked into the
paint. So on most ablative paints, a light scrub with a no-scratch, plastic household scrubber
will remove any dirt or contaminants and you’re good to go. That said, a few ablative paints
used on racing boats are so soft that even a light scrubbing may remove most of the paint.
If you think your paint might fall into this category, check with the paint manufacturer first.
A hard modified epoxy paint has an open binder, so the copper is exposed to air and it will
oxidize over the winter. Don Zabransky from Pettit Paint says, “It’s very difficult to say how long
a boat can sit without this kind of paint becoming ineffective.” He recommends sanding a hard
paint down and applying one fresh coat before launching to ensure protection for the season.
I just read Don Casey’s article on hull blisters (June 2013) and found it both informative
and a little disconcerting once I realized blisters are present on my 2000 Regal 2100 LSR.
PRACTICAL ASK THE EXPERTS
BOATER SOLUTIONS FROM THE BoatU.S. TECH TEAM
Is bottom paint less
effective when the
boat’s been out of the
water for a long time?
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I’d noticed them before and honestly never
given them a second thought, thinking
they were harmless or even purposely there
from the factory — like dimpling on a golf
ball. The blisters are very small, with the
largest of them being smaller than a dime.
They’re very prevalent just below the waterline around midships, and also show up on
the rear third of the hull. A few have cracked
and peeled off, leaving a very shallow pockmark in the gelcoat. My boat was kept in a
slip for its first decade but is now trailered. If
I don’t address the blisters now and continue
to trailer the boat, am I risking exponentially
raising the eventual repair cost? If the blisters
do not increase in size or number, do they
need to be addressed at all?
DON CASEY: Answering the last ques-
tion first, you really should repair at least
the open blisters just to shield the exposed ILLU