The Gougeon Brothers on Boat Construction - WEST SYSTEM Epoxy

Chapter 21 – Laminating Veneer Over a Mold or Plug 231
Figure 21-3 Veneers in interlaminate layers of this laminated hull are butted randomly. This reduces scrap and eases lay up
without sacrificing the strength of the hull. Note the final layer of veneer being laid fore and aft at the lower left.
to work with this angle and your stock until you find
the most efficient use of the veneers you have on hand.
You can greatly cut down on scrap by butt joining or
scarfing shorter pieces of veneer. In thick laminates,
butts are perfectly acceptable as long as they are
staggered across and through the structure. Wood is
many times stronger in tension than it is in compression,
and a properly bonded butt joint can transmit
100% of all compression loads. Wood’s excess tensile
strength permits the use of butt joints with a good
degree of safety in a hull with many laminations.
When a hull has only two or three layers of veneer,
however, we recommend that you choose 8-to-1 scarf
joints instead of butt joints. Use the Scarffer attachment
and the plywood scarfing techniques described in
Chapter 12 to cut your bevel. Assemble and bond the
joint right on the mold. For accurate fits of both butts
and scarfs, remember to cut the ends of your veneers
exactly flush at right angles to their straightened sides.
Inserting and Removing Staples
Successful lamination is closely related to your expertise
with a staple gun. Staples are used on every layer to mold
veneers in place until the epoxy has cured, so you will
shoot and remove a great many of them. Master several
easy techniques before you take aim at your hull.
<strong>The</strong>re are several things to think about as you staple
layers of veneer: the orientation of the staple with respect
to the grain of the wood, the pressure pattern applied
by each staple, and if and how you will extract the staple.
As you work you exert pressure, which the staple
maintains.
For maximum holding power, always insert staples so
that their crowns are perpendicular to the grain of the
wood. This will also reduce any damage the staples may
do to wood fiber, so it will save some filling on the last
layer. Staple holes parallel to the grain are much less
noticeable than those which run across the grain.