Hoses

Few of us ever pay much attention to things that are inherently
safe, right? We have a tendency to use infamous phrases like
“What could possibly go wrong”. Lulled by endless years of
faithful service we have a tendency to ignore, or take for granted,
parts of our boats that never seem to cause problems. Yes, we
give them cursory inspections from time to time, but do we really
know what we are looking at, and do we understand the applica-
tion in which it’s used?

How about something as reliable as a hose? Lately I’ve
been exposed to several situations where something as simple as
a hose, was used in such a way that it was a set-up for disaster.
One of the first things we have to understand is that hoses have a
life span. They don’t last forever. Most manufacturers recom-
mend that marine hoses be replaced every ten years, whether
they look worn out or not. Environmental factors; heat, cold,
exposure to oils, gasses, and other chemicals will gradually
break down the rubber and other materials used to construct the
hose and it will eventually fail. Even following a good routine of
inspections you may not be able to detect the imminent failure of
a hose. The outside may look fine, no cracks, chafe, drips or
other damage. But what does the inside look like? Has an over-
tightened clamp crushed the inner lining of the hose so that it’s
really only the outer covering that’s holding back the ocean? Has
corrosion of the reinforcing wire on your raw water intake hose
advanced to the point where it could collapse under the suction
of the raw water pump and starve the water flow that cools the
engine and its exhaust? I have to admit that a few of the hoses on
my 30+ year old boat have exceeded that 10 year replacement
recommendation from time to time but since rebuilding the
engine the oldest hose is now the garden hose I use to fill the
potable water tank.

Another important thing about hoses is how we connect
them to the systems on our boats. I’m a firm believer in using
proper hose barb fittings and double hose clamps for all under
water applications. Slipping a hose over a smooth surfaced pipe
doesn’t give the hose anything to “grab” no matter how much
you tighten the clamps. Although threaded pipe gives you
something to grab, tightening the clamps against sharp threads
results in cutting the interior surface and setting the stage for
further deterioration. A properly sized barbed fitting and a hose
clamped with moderate torque will last for the life of the hose
and is able to withstand considerably more pressure than any
other form of attachment, with the possible exception of a
swaged fitting which would be totally impractical for this appli-
cation.

Bill Lundquist recently identified several of these “what
not to do” situations while upgrading many of the systems on his
Petrel. When inspecting one of his deck scupper drain through
hulls below the waterline, Bill could see rubber, and could stick
his finger in and feel rubber hose. What was holding it on the
through hull? Where was the through hull? A quick look at the
inside of the hull showed a scupper hose going through the
ceiling and disappearing into the unknown. Upon removal of the
woodwork he could see that there were some significant
problems with this installation. There was no through hull! The
hose was just fiberglassed to the hull. This was a 30+ year old

heehee
boat. When do you think the 30+ year old hose was last
replaced?

Although these problems were identified on a fiberglass
boat similar issues can be found on many wooden boats. The
hose has never leaked, why fix it? I like to ask the question
differently: ‘how confident are you when the weather kicks up
and it’s a long way to shore?’