The Gougeon Brothers on Boat Construction - WEST SYSTEM Epoxy

206 First Production Steps
Beveling
Frames are beveled so that planking can bend evenly,
with smooth curves, over them. Begin this operation by
rolling flat black paint on the edges of the frames. Most
of this paint will be planed away; the object is to leave
a thin line of black on the controlling edge so that you
know it has not been disturbed.
Use a batten that spans at least three stations as a guide
for beveling. Lay it over three frames and nail down its
ends. If your mold frames are only 1 ⁄4" (6mm) thick,
you can just hack away excess stock from the middle
frame. If they are thicker, take a handsaw and cut
marks on the edge of the middle frame on either side of
the batten parallel to it as it crosses the frame edge at an
angle. Cut no deeper than the black control edge. Move
the batten up and down the frame, sawing or hacking
every foot along its edge. Check for fairness. When you
have finished one frame, move on to the next.
When all larger frames are marked, chisel away the
wood between the kerfs so that you have a series of
notches. Check again for fairness, and then scribble
across the bottom of each notch with a pencil. Using
the pencil marks to guide you, plane the entire edge of
the frame. We use power planes to rough-cut bevels,
but advise against them unless you have some experience
with these machines. Hand planes do just as well,
though at a somewhat slower rate.
Fairing
Once you have rough cut the bevels so that only a thin
line of black remains on the controlling edges, you are
ready for final fairing. As in lofting, the eye and artistic
sensitivity are the main tools. <strong>The</strong> object is to make the
long batten touch all the controlling edges under it and
form a curve free of lumps or flat spots in all positions
on the length of the set-up.
To accomplish this, it may be necessary to cut below
the marked black control edge in some areas, and to
build up above the edge in others by bonding on strips
of wood or not beveling to the full depth of the saw
cuts. Accurate work in lofting, picking up, cutting
frames, constructing them, and setting them up will
Use a batten and saw
to get rough bevels
Batten Molds
Dress lightly with
plane to obtain
clean fair
surface
Chisel out stock
between kerfs
Chisel to
marks
Figure 18-9 Beveling mold frames.
hold errors that have to be corrected in this manner to
a minimum. Minute errors in each of these operations
are practically unavoidable, but for the most part they
cancel each other out. In some areas, though, the errors
will all add up to something that has to be corrected.
In final fairing, the batten tacked across the mold
frames sometimes looks wrong or irregular because of
the way in which it is positioned. Do not undertake any
corrections on the basis of a single batten position.
Move the batten all about the set-up, and make an
overall analysis of what has to be done. Carefully mark
errors on the frames in the exact area where you
observe them. As you place the batten in various
positions (this is especially a problem in areas of difficult
curves), the error in one area may read differently,
creating some confusion, and you have to make a
judgment between conflicting dimensions as to which
one is the real error. Sometimes a compromise between
measurements results in the best fairness.
When you are certain what corrections are needed,
make them by planing below the marked control edge
or bonding on shims. Work until the set-up is fair,
without any humps or flat spots.