The Gougeon Brothers on Boat Construction - WEST SYSTEM Epoxy

Chapter 18 – Setting Up 203
Figure 18-4 Setting up the first frame.
Place the station so that the straightedge is next to the
cable but not touching it. Put clamps over the legs and
anchoring blocks and tighten them at least enough to
keep the frame from falling over. Screw type C-clamps
are more satisfactory than sliding, quick-action clamps
because they do not fall off when you make adjustments.
Put a temporary diagonal brace in with clamps
as you plumb the station fore and aft with the spirit
Plumb line may be
used to center mold
instead of straightedge
Centering cable
Spall
Figure 18-5 Two views of a typical frame set.
Notches for keel and stringers
Light
straightedge
clamped on
mold centerline
and set at reference
waterline
for adjusting
and centering
Shim
Cleat
Wedges for height adjustment
2" X 4"
Floor
level. You can loosen the clamps on the legs enough to
allow the legs to slip on the anchoring blocks while
adjustments are made.
To position the stations, you can use either a plumb
bob or the two-level method. As mentioned earlier, the
plumb bob ensures greater accuracy. To use the plumb
bob, attach it at the station vertex on the centerline with
a spring clamp and enough string so that the point of
the bob barely clears the centering cable. Place the bob
on the opposite side of the station from the straightedge
so they are not in the way of each other.
Next adjust the position of the station until the
following conditions simultaneously exist:
1. <strong>The</strong> plumb line is over the centerline of the frame,
with the point of the bob over the centering cable;
2. <strong>The</strong> frame is plumb fore and aft and free of twist;
that is, the frame is exactly perpendicular to the
centering cable;
3. <strong>The</strong> cable mark on the straightedge is level with the
cable.
All reference lines should be marked on
both sides and edge of mold.
Control edge or face
goes on station line
leg (joined edge
fastened to control
face of mold)
Brace or jigging
lumber – bonded
and fastened
Wedges
Centering cable
Mold beveled on
this side
Waterline marks
for reference
Spall
Cleat on
station line