The Gougeon Brothers on Boat Construction - WEST SYSTEM Epoxy

Chapter 21 – Laminating Veneer Over a Mold or Plug 245
When you have completed the last veneer, laminate and
install a stem cap. Further layers of wood may be
needed to complete the keel profile. In most cases, you
can hold these in place with screws until the epoxy
cures. For extreme curves, use washers under the screw
heads for extra pressure. If this is not practical, make a
temporary form in the shape of the stem or keel,
allowing for a bit of springback, and laminate the part
on this. <strong>The</strong>n rough saw and bond the piece in position
for final fairing.
Final Fairing
Fairing is one of the arts of boatbuilding. We doubt that
anyone has ever built a perfectly fair hull, but we’ve
seen some that have been close to it. Up to a certain
point, fairness is a necessity because fair hulls offer less
resistance than hulls with humps and hollows. After
this, fairness is no longer important as far as movement
through the water is concerned, but becomes a point of
personal and professional pride.
You should usually complete final fairing and finishing
before you remove a laminated hull from its mold. <strong>The</strong>
exception to this is a thin-skinned hull, which needs
additional support from internal framework. In this
case, you would final fair the hull after installing the
framework.
Before final fairing, rough fair the last layer of veneer to
remove lumps of epoxy and obvious high spots as you
have on previous layers. Block or smoothing planes and
slightly flexible sanding blocks with 60 or 80-grit paper
are good tools for rough fairing. Don’t use air files and
other power machines to rough fair hulls that will be
naturally finished. Unless you have a lot of experience
with power tools, you run a high risk of leaving
scratches in the wood and these may show up in the
finished surface.
<strong>The</strong>re are two parts to final fairing. <strong>The</strong> first, local
fairing, is the process of making the hull smooth to the
touch in a specific area. Overall fairing, the second job,
is more difficult. A hull may be sanded until it is very
smooth, but it still may not be fair overall. It’s usually at
this point that large overall hollows and bumps are
visible. It’s important that you do everything you can to
Figure 21-23 This hull is being finish sanded in preparation
for epoxy coatings. Note the veneer seam along the bilge.
Topsides on this hull were choice veneers carried from the
sheer to just below the waterline.
be sure of general fairness before you coat the hull
because it’s very difficult to correct overall fairness
problems after coating.
Final fairing involves finding high spots and removing
them so they blend in with the overall surface area. <strong>The</strong>
difficulty is in determining exactly where these high
spots are before you start planing or sanding. As you
work, continually move around and look at the hull
from different angles.
A chalk stick works quite well to help find high spots
and can be used to quickly identify them and check
your work. Make one from stock between 3 ⁄4" (18mm)
square and 11 ⁄4" (32mm) square, approximately 6' (2m)
long. Use the straightest wood available that will also
bend in a fair curve. Apply carpenter’s chalk to the
surfaces of the stick and bend it around the hull until
most of its surface area is firmly touching the hull.
Move the chalk stick back and forth slightly on the
hull so that it deposits chalk on the high spots. <strong>The</strong>n
concentrate sanding and planing to bring these areas
down to fair. You can use the chalk stick as often as
you like to monitor your progress until you are satisfied
with your hull’s fairness.
Always do your final fairing by hand, with 50 to 60-grit
paper attached to a block and hand planes with sharp,
fine-set blades. Sanding blocks should bend slightly to
conform to the contour of the hull. We make ours out