Prevention and Maintenance of Deck Leaks
by Tom Neale
Fortunately there are products to help with deck leak control.
its always theoretically better to remove and reseat
any deck components
with leaks underneath, these products allow a little successful
Weve used Capt Tolleys Creeping Crack Cure for
small cracks around
port lights and windows. Weve found Liquid Life Calk
to be helpful to
fill in larger voids. In our experience, Life Calk, if squeezed
under the deck hardware that its sealing, will be degraded
by UV. But
if you carefully use just enough so that its covered
by the deck
hardware and not exposed to the sun, weve found it to
work very well.
Silicone products, weve found, are less likely to be
degraded by UV when
exposed, but dont seal as long as Life Calk when used
to seal a piece of
hardware fastened to the deck.
No matter how hard you try to keep on top of things, there
come the time at the beginning of a week long monsoon when
discover a new leak. If you know where it is, you may be able
to fix it,
even in the rain. One possibility is---yes, duct tape, if
source is on a reasonably flat surface. One partner stands
by with a
strip of tape, cut from the roll and ready to go. Keep the
dry. The other dries the offending area with a fluffy towel,
over it as he does so, to shield it from more rain. As soon
as its dry,
slap on the tape. Quickly press down hard over its entire
will probably stem the flood for the duration. Remove the
tape as soon as
the sun comes out so that it wont leave residue. If
it does, remove it
with a product like Goo Gone.
Theres yet another trick. Because Life Calk (and similar
designed to bond and set up under water, Ive been able
smear some of this, during rain storms, into an area where
a new leak has
developed. I try to dry the area with a towel as well as possible
This will probably leave a mess, but you can usually clean
that with a
product such as Acetone. (Read and heed all the warnings on
and never store this or similar products below decks or in
When you make (or discover) a hole through a cored hull, especially
balsa, scoop out the coring material between the two layers
around the hole. The extent of the void you make depends upon
of the hole. It usually should be at least a quarter inch
holes (such as Bimini fasteners) and perhaps up to an inch
or more for
large holes such as those for bolts. Then fill the void with
other suitable material (read product literature at the marine
let it harden, and re-drill. This not only keeps water from
into and through your core, it also adds needed strength to
section through which youre mounting your component,
and helps prevent
rot or other disintegration.
We only use sealants that are designed to remain flexible
or reseating an object on deck. Anything that cures to rigidity
probably work loose during stress flexing. Most marine sealants
designed to remain flexible. When youre using these,
tighten down the bolts or screws most of the way when you
do the job, but
not completely. Dont torque down all the way until AFTER
has had a chance to cure. This is usually around 24 hours.
avoids pushing all of the sealant out while it is still wet.
instructions on the label of the sealant.
To read more about deck leaks, go to the Toms Tips section
Neales Cruising for You on www.boatus.com.