The Gougeon Brothers on Boat Construction - WEST SYSTEM Epoxy

Interior Construction
This chapter discusses approaches and techniques for interior construction. Like the previous edition, it
also includes information on building tanks. While many successful tanks have been built using these
techniques, the regulatory environment has evolved over the last 30 years and has placed safety restrictions
on various aspects of tank building, specifically potable water and gasoline tanks. Additionally,
gasoline formulations have changed and some can soften epoxy coatings over time. Because of this, our
recommendations on tanks have changed from earlier editions.
Boat interiors can range from the very simple to the
highly complex. Typically, large boats tend to have more
complete interiors than small boats, and cruising boats
have more highly developed interiors than racing boats.
It has been said that a boat with a perfect interior has
yet to be invented. <strong>The</strong> age-old problem of trying to
put a lot of accommodations into a limited amount of
space is a difficult design problem. We feel that boat
designers really earn their money when it comes to
interior planning and layout.
We are not interior design specialists, but we do have
definite thoughts on interior construction. Our
approach may be closer to the one used in aircraft
design than to traditional boat design in that we think
that the interior should be an integral part of the structure.
Our approach may also offer designers more
flexibility in the use of space and materials. We’ve had
clear objectives as we have worked on interiors. Of
these, keeping weight to a minimum, using the interior
to improve the vessel structure, increasing interior
utility, and improving interior appearance have been the
most important.
Unfortunately, the joinery for most boat interiors will
require a significant portion of the labor hours needed
to build the boat. Professional builders are well aware
of this problem, and many a builder has learned the
hard way by underbidding this part of the boat. More
than any other aspect of the boat, interiors require
planning and strategy for the most efficient use of
materials and labor hours. Over the years, we have
developed a few simple techniques which have helped
to reduce the labor hours needed for interior work and,
at the same time, have made interiors more enjoyable
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to work on. We present our suggestions here, but we
must also emphasize that every boat interior will
present its own unique construction problems. Careful
thought, common sense, and an open mind are all
needed to choose the best construction strategy.
Objectives for Interior Construction
Keeping interior weight to a minimum
On racing boats, the weight of interior amenities has
always been looked at with a critical eye. <strong>The</strong> added
weight of any interior, even on a heavy cruising boat,
should be carefully considered. Interiors are usually
non-structural or secondary structural items. <strong>The</strong>y need
not be built with the safety margins required for the hull
and deck structure. Construction with our methods can
make interiors lighter. If you can save 200 or 500
pounds on a cruising boat’s interior, you can lessen the
vessel burden and increase its capacity to carry fuel,
water, or stores.
Using the interior to improve the vessel structure
With proper planning, it’s possible to install many
interior items so that they help to reinforce and support
the hull skin. When bunks, shelves, cabinets, and tables
are correctly bonded to a hull, they can contribute to its
strength and also add stiffness to the structure by holding
the hull skin in position in their immediate areas. This
is especially effective if the vessel is designed from the
start so that interior items are laid out to provide the
most support. <strong>The</strong> interior is no longer just dead weight
for the hull to carry around. Instead, it contributes to
the overall integrity of the vessel. By becoming structural,
interior items at least partially pay for themselves
on a weight-to-strength basis.