The Gougeon Brothers on Boat Construction - WEST SYSTEM Epoxy

210 First Production Steps
Stem laminations are usually thicker and may present
greater springback problems. If it’s impossible to push a
stem into shape, you may have to laminate extra stock
onto one side and plane away wood from the other to
regain the designed curve.
Laminating Forms
<strong>The</strong> stem may be the largest and most difficult laminated
piece in your hull. It’s also usually one of the first laminated
components you’ll need. Practice with a dry run
before applying WEST SYSTEM ® epoxy to the stem blank.
We usually lay out and bond stem blanks on the floor,
using triangular blocks to make a form as described in
Chapter 11. Take care to avoid any twisting in the
laminate. <strong>The</strong> stem is aligned along the centerline of a
boat so any distortion will complicate marking the
centerline and positioning the stem in the set-up.
Triangular blocks may also be used to laminate keel
blanks. We often laminate keels right on our set-ups,
using mold frames as forms. <strong>The</strong> difficulty with this
is that the laminating stock is usually wider than the
trimmed keel will be, so the lamination must be
completed before any notches for the keel can be cut in
the permanent or mold frames. <strong>The</strong> trick is to work out
an adequate form without damaging the mold frames.
We recommend the following procedure in this situation.
Measure up from the bottom of the marked keel
notch enough to clear the notch. Draw a line across the
frame, parallel to the base of the notch. Mark all frames
in this way and saw them off flush with these lines.
Screw or clamp 11 ⁄2" (38mm) square cleats or blocks
to the control sides of all mold frames. Clamp them to
permanent frames. <strong>The</strong>se will be points that you can
clamp to the keel blank. Include limber holes at the
frame/keel joints by cutting notches a little wider than
needed for the keel blank. Be careful not to remove so
much stock that the frame becomes too weak to support
and outline the hull shape. On thick keels, limber holes
that do not extend the full depth of the notches can
work effectively.
You may need temporary jigging aft of the transom and
up around the bow for laminating to help coax the keel
blank into bending as it approaches these areas. This
jigging can consist of a temporary addition to a bow
frame and a partial frame just aft of the transom.
Figure 19-3 Set-up for the 42' (12.8m) Golden Dazy. <strong>The</strong>
keel can be seen on sawhorses beyond the molds. <strong>The</strong> slight
rocker in this hull allowed the use of a solid keel.
Because of springback, it’s often a good idea to slightly
overbend the keel toward the bow and stern.
When the keel lamination is in position, clamp it
securely at each station point, covering each station
with polyethylene sheeting to keep epoxy from dripping
onto permanent members and accidentally bonding the
keel to the mold forms. Use clamps at each edge of the
keel to hold it to the blocks on the mold frame. To be
sure that there is adequate clamping pressure on the
laminate between stations, use hand clamps with
clamping pads to spread the load. Remove any epoxy
that squeezes out of the lamination.
Joining Keel and Stem Blanks
Mark centerlines and station lines on the stem and keel
blanks while they are still in the set-up. To mark the
interior of the stem, hold a plumb bob under the stem
and drop it to the centering cable. Mark the location
from which the plumb bob falls straight to the cable at
intervals along the stem and draw a line with a batten
to connect the marks.
Use a level to lay out station lines and any other frame
locations perpendicular to the centerline. <strong>The</strong>n mark
the widths of the keel and stem on their respective
blanks. Rough plane the side edges of the blanks to
these dimensions, but wait to taper any thickness until
after the pieces have been joined. Place the keel/stem
template on the blanks or take them to the lofting.
Transfer all reference lines and marks for the scarf.