Instruction manual

FRAMING THE PLANK-ON-BULKHEAD HULL
1. Bending Wood
Building a P-O-B hull requires some wood bending
and twisting, and the wood must remain in the
desired position so as not to put too much stress on
glue joints and fasteners. The term “steam-bent” will
be used throughout the text whenever such a process
is necessary. However, here are three ways to do it.
Steam-bending
–For actual steam-bending, hold the
piece over a kettle of steaming water and bend. Hold
the wood in position until it cools. It should remain
nearly in that position, but may spring back slightly.
Soaking–Another method is to soak the piece in
warm water for several hours. Try adding a little
household ammonia to the water. You can also use
pure ammonia. This speeds up the soaking process
and makes the wood fibers slippery so the wood is
easily bent. Hold the wood in position with a form
after soaking and let it dry completely.
Hot iron
–You may also bend wood quickly over a
soldering iron, but don’t let it get too hot. A large sol-
dering iron with a tubular end is ideal. The tube near
the handle is not as hot as the very end. It is also pos-
sible to purchase model plank bending irons com-
mercially. They are designed for controlled heat.
2. Center Keel Assembly
The first step in constructing the hull is to assemble
the two laser-cut center keel pieces. First, use a sharp
pencil and mark the bulkhead locations below the
slots and the WL reference lines. One line is used to
locate Bulkheads “A” through “L” and another for
locating Bulkhead “M”. Mark on both sides of each
center keel piece. Be especially critical in locating the
reference lines. Measure from several points from the
plans. The reference lines are a key to proper align-
ment.
Place the two parts, 1 and 2, over a sheet of wax
paper or plastic wrap, on a flat building board or
table. Glue the joint with white or carpenter’s wood
glue. Use a steel or aluminum straight edge to align
the WL reference lines. Place a weight on each piece
to hold it down while the glue dries. Let the glue dry
at least overnight, preferably 24 hours (see figure 1).
3. Cutting the Rabbet
Cut the rabbet in the center keel. The bearding line is
the intersection of the center keel and the inside face
of hull planks. After the center keel is ready, mark the
bearding line on both sides. The bearding line
appears along the sternpost and the keel/stem. Mea-
sure from the P-O-B plans. Using a chisel, start the
rabbet cut at the bearding line and cut toward the
edge of the center keel. When the planking is
installed, the planks will lie flush on the cut portion
from bearding line to rabbet (see figure 2).
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STAGE A