The Stitch and
glue method of boat
construction is faster and lighter than traditional
The development of epoxy
resins and quality
revolutionized wooden boat building for the self builder.
This method of building requires very little skill.
There are only a few simple techniques which need mastering, plus some
basic woodworking knowledge.
glue boats are constructed by
gluing panels of plywood together using epoxy resin and fiberglass.
The stitching is used to hold
the panels in place while
the glue is applied and allowed to cure.
Stitching planks together in
not a new method of boat
building, it has been used for centuries, what makes it so suitable for
home builder is the use of epoxy.
While there will be variations
between different stitch
and glue boat designs, the basics are the same.
Boat Books on-line
cut to the correct size and
shape, this is the most critical part.
If you are
building a kit boat
the panels will be either pre-cut or at least marked out, otherwise you
at least be working from a proper plan.
The planks are sewn
by drilling small holes
along the edges of adjoining panels, then using short lengths of copper
The wire is threaded
the holes and twisted to
pull and hold the panels tightly together until they are glued.
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twister tool can be
used to speed up the stitching process.
Plastic cable ties can be used
Many stitch and glue builders
are finding these ties to
be very convenient and faster to tighten.
They are also easier to snip
off and can be sanded or cut
flush once the glue has cured.
However, they do require a
larger hole than wire and once
tightened cannot be adjusted.
Wire stitches can be difficult
to remove completely,
sometimes it is necessary to heat the wire.
But it is much easier to fine
adjust with copper wire and
get sufficient pressure where there are tight bends.
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Stitch and Glue Fillets
The reason that stitch and glue
is faster and
simpler than traditional methods is that it eliminates the need for
complicated forms, and tricky clamping.
And the major factor involved
is the use of epoxy fillets.
These not only glue the
plywood panels but also cove out
the inside corner where the panels meet.
Fillets are very easy to apply
and add to the strength as
well as enhancing the boat's appearance.
Fillets are made with
are many thickeners
available commercially, such as
micro balloons, talc and silica.
You can use sawdust, white
wheat flour, pulverised
limestone and even Portland cement.
Whatever you use the point is
to produce a mixture that
won't sag or run and will be easy to smooth and will sand easily when
mixture should be
the consistency of smooth peanut butter.
Apart from the mixing spatulas
and cups you will want one
or two plastic spreaders or squeegees.
You could use an off cut of
wood but thin plastic is
easier clean and shape.
Radius one edge of the
spreader to suit the fillet, a 2
inch radius will do for most seams in a small boat.
thickened epoxy is
mixed to the ideal consistency you need to get it onto the seam quickly
it begins to 'go off'.
You won't have a lot of time
so make sure every ting is
ready and you have decided where it is to go.
Then scoop big blobs of the
thickened epoxy every foot or
two along the seam.
start to smooth it out
with the filleting
Use the flat side of your
squeegee to scrape away the
epoxy which squeezes out on either of the fillet before it can set.
The process can be a bit of a
messy but try to keep the
fillet as neat as possible to reduce the need for a lot of sanding once
On the other hand don't try to
do any touching up
once the epoxy starts to stiffen as it will only make matters worse.
the stitch and glue
fillet has cured it needs to
be strengthened and protected with a layer of fiberglass tape saturated
This is best applied onto the
fillets while they are
Just be careful when laying it
not to mess up your
carefully applied fillets.
See the comment below for a useful tip when smoothing fillets.
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The standard size of a plywood sheet
is 8x4 feet, so any planks that need to be
longer than that will have to be joined using a scarf joint.
Scarf joints, bonded with
epoxy are incredibly strong,
stronger than the surrounding wood.
Often when gluing a scarf or
other joint epoxy squeezes
out when it is clamped.
This then has to be sanded and
scraped off once the glue
One way to avoid all that
sanding is to mask off around
joint with some cheap electrical tape.
Then later this can be pulled
off taking the excess glue
Or see "Joining Plywood Sheets and Planks" John Sheen
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stitch and glue boats are given a sheathing of fiberglass cloth soaked
This layer is used to add a
high degree of protection,
strength, abrasion and impact resistance.
The lower cost chopped strand
mats will add bulk and
stiffness but not much strength.
Unidirectional cloths will add
strength along the
direction of the weave.
Woven and knitted cloths will
When all the
has been done and the whole surface sanded to an acceptable finish the
surface must be protected from UV light.
Whether you paint or varnish
and however much time and
effort you put into the finishing, at least two or three coats of
paint will be needed to protect the epoxy from the sun's rays.
Use the time you have saved by
using the stitch and glue
method to make a good job of the finishing off.
A nicely finished
boat will add
to the pleasure of using it.
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