The Gougeon Brothers on Boat Construction - WEST SYSTEM Epoxy

Chapter 22 – Stringer-Frame Construction 253
Figure 22-5 A marking gauge or fid.
Small section
of stringer
Thin plywood pad
Marking fid used
to mark or clean
stringer notches
When you have marked all of the stringer outline
positions, you can begin notching. Many methods are
used to notch frames to accept stringers. <strong>The</strong> simplest is
to use a handsaw to saw along the sides of the marked
notch down to and flush with the bottom of the notch.
Make several more saw cuts in the center of the stock
left in between the notch markings down to the bottom
baseline. <strong>The</strong>n use a sharp chisel to cut along the
bottom of the mark in the slot on each side of the frame
until you remove all material in the slot area. Until you
get good with the saw, start by cutting the slots slightly
undersize and then file them out by hand to a snug fit
with the stringer. Use a sample piece of stringer to
check your notches. You can speed up the notching
operation with the use of power tools, such as a reciprocating
saber saw or a power circular saw with the
blade set to the proper depth. We would advise caution
in the use of either of these tools, however, because you
need experience to perform accurate cuts.
Fitting and Fairing Stringers
An advantage of the stringer-frame method is that
frames only need rough fairing as you set up. You can
bevel and final fair the frames when you install the
stringers. <strong>The</strong> stringers act as fairing battens: you can
adjust them in and out of their notches to compensate
for a frame which is too low or high at any point. If, as
an example, a stringer makes a hard spot in one frame,
correct it by filing its notch a little deeper until it lies
fair. If, on the other hand, a stringer looks flat on a
frame, shim it up in its notch with a small wedge.
During the process of fitting and fairing stringers in
their notches, you will also fit the ends of the stringer to
the stem and transom. You can cut triangular notches in
the stem and fit stringers into them. We often notch
stringers into the back of the stem lamination and then
use triangular plywood breasthook-like gussets to make
a triangular joint with the stringers on either side of the
hull. With either method, fit the stringer at the stem
and then set it into the notched frames working aft
from the bow.
We usually notch stringers into a partial transom. <strong>The</strong>n,
when the hull has been laminated, we add layers to the
transom. We notch the partial transom and slip stringers
into it in the same way we do with frames. However, if
you have a full transom, you may want to cut triangular
Stringers set
into triangular
notches in the
stem
Stem
Plywood breast hook
Figure 22-6 Fitting stringers to a stem or stern post.