Sequoia Aircraft Corporation F.8L Falco, Construction Manual

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F.8L Falco Construction Manual 10–4 Revision 4, March 1, 2002
rolling table
lower tenoner head
hold down bar
piece being scarfed
jig
Figure 4
There are many other methods of scarfing plywood. A tenoner may be used as shown in Figure 4.
This method may be used for spruce or plywood. While few Falco builders will have such
equipment, you may be able to use other available equipment in a similar fashion.
Spruce is normally cut with a saw, and again the radial arm saw is the most convenient way of
making this cut. The gauge block comes in handy to set the angle of the cut. A table saw may
also be used.
jig
this part of jig acts as clamp
piece being scarfed
jointer bed
jointer bed
head
Figure 5
A jointer may be used for scarfing spruce as shown in Figure 5. Some builders have used a similar
method by making a jig for scarfing spruce with a portable power plane. In these cases, the plane
is guided by tracks so that it does not cut into the jig.
Generally, it is best to scarf the plywood in advance, but when this is not possible you have to
make a scarf joint on the airplane. This often happens when you glue on a skin which will have
to join with an adjacent skin panel. The skin should first be trimmed so that it is even with the
edge of the underlying structure, usually a rib or fuselage frame. A laminate trimmer bit in a
router does a nice clean job and doesn’t splinter the plywood as saws do. This end of the plywood
will determine one edge of the scarf. The other edge may be determined by measuring. Let’s say,
for example that you have a 1mm skin, and you want to make a 12 to 1 scarf. Obviously, the scarf