The Gougeon Brothers on Boat Construction - WEST SYSTEM Epoxy

254 Hull Construction Methods
Figure 22-7 Fairing the molds on a stringer-frame set-up.
notches in it as you did the bow so that the end grain
of the stringers is not exposed.
When you have temporarily installed all of the stringers
and they lie fair, mark them at various points so that
you can remove them in preparation for final assembly.
If you have not already done so, round off the exposed
interior stringer edges between the frames, and sand
and coat them. Prefinishing individual parts before they
are installed is particularly important with this
laminating method because a stringer-frame interior is
difficult to coat and sand adequately later on.
Before reinserting stringers, apply a thick, high-density
epoxy mixture to the inside edges of all of the stringer
slots in the frames. It is not necessary to apply epoxy to
prefinished stringers before installing them, although in
some situations coating both surfaces ensures better
contact. If you have cut the notches carefully and the
stringers fit snugly, you will need very little outside help
to keep the joints together until the adhesive cures.
Usually, a few staples or a couple of clamps in the right
places on each stringer will hold it in position. On
permanent frames, remove all adhesive which has
Figure 22-8 Stringers may be shifted slightly to facilitate
bending, fitting or bonding.
squeezed out of the joints. We sometimes use this
excess epoxy mixture to make small fillets between the
stringers and frames to increase the bonding area.
In areas where the stringer is notched into a temporary
frame, don’t put adhesive in the notch because later
you will want to remove the temporary frame without
damaging the stringer. If the notch in the temporary
frame fits tightly around the stringer, probably nothing
else will be needed to hold the stringer in proper
position. However, if it is a sloppy fit, further position
the stringer with some fine wedges driven between
the stringer and the gap that might exist on either
side. In some cases, we have also used a small fillet,
which we later chisel away, to hold a stringer rigidly
to a temporary frame.
When all of the stringers are permanently installed, begin
a final fairing of the entire hull surface. It is now very
easy to bevel the frames, using the installed stringers as
guides to achieve perfect bevels from frame to frame. If
you have made any mistakes and have humps and
hollows that need correction, these are still easy to take
care of. Correct an offending high stringer or frame by
planing it away until it fairs in with the rest of the hull.
Correct stringers or frames that have low spots by
laminating on a layer of 1 ⁄8" (3mm) veneer or plywood
and later fairing this addition in with the rest of the hull.
To the uninitiated, fairing intermittent stringers may
seem difficult because most of the hull surface is still
open space. With the strip plank or mold method, it is