Introducing the Devlin "Stitch and Glue" Method
Devlin Designing Boat Builders are master craftsmen when
it comes to wooden boat construction. Our "Stitch and
Glue" method is a vastly superior approach when compared
to traditional boat assembly methods and delivers
stronger, better boats. The Devlin Method uses epoxy to
bond and seal all parts together thereby achieving a
stronger, one-piece boat design. The initial
construction is quicker, easier, and needs fewer
parts. This approach does not require expensive building
molds. More importantly, it results in a boat that is
much easier to maintain over the long term.
"Stitch and Glue" construction
is a technique using very high grade marine plywood,
simple wire sutures (to clamp together the panels of the
boat until they are fused together permanently),
fiberglass tapes, fiberglass or Dynel Polyester cloths
for sheathing, epoxy fillers, and epoxy resin. For a
simple Vee-Bottomed boat, the basic steps for the
builder are to cut out the two bottom panels, the two
side panels and the transom. These parts are then
stitched together with the wire sutures along the panel
edges or seams. The wire sutures clamp and hold the
panels together until the epoxy/fiberglass cloth fusing
mixture is cured, then the wires are removed. For this
fusing joint, the epoxy resin is thickened with the
fillers or hardwood flour (finely ground hardwood
sawdust ) and then applied to the seam in a thick,
continuous bead over which layers of fiberglass cloth
tape are applied. Each tape layer is completely
saturated with Epoxy resin before applying the next
layer (wet on wet). Once all the interior seams have
cured up (overnight), the hull is turned over, the wire
stitches (sutures or clamps) are removed and the seams
and edges are smoothed over and faired in anticipation
of sheathing the entire exterior of the hull with
fiberglass or Dynel using the epoxy resin to completely
saturate the cloth. The key to the method is that all of
the structural surfaces must be saturated with the
resin. Using marine quality materials will always ensure
a quality product.
When you purchase a set of plans, we include a
step-by-step building booklet, a materials list, a
source list, and even a list of the tools necessary for
the basic construction. One nice thing about "Stitch and
Glue" construction is that fewer tools are required
compared to other methods of construction.
"Stitch and Glue" construction allows the builder to
once again utilize the strength and beauty of wood while
eliminating the negative maintenance problems so
prevalent in the past with wooden boats.
The Advantages of "Stitch and Glue" Boat Building
The differences between conventional plywood-on-frame
and "Stitch and Glue" construction are significant. To
better understand the differences between the two,
contrast the structural dissimilarities of an early
biplane and a modern jet airliner. The biplane was made
up of frames and spars over which was stretched a thin
skin. The jet airliners structure, on the other hand, is
simpler, with a stressed aluminum skin rigidly
attached to bulkheads and spars to create a single monocoque unit. A boat built by attaching plywood
planking to lumber frames is most similar to the
biplane; a "Stitch and Glue" more closely resembles the
jet airliner, a homogeneous structure in which the skin
bears the primary stresses.
The basic argument for "Stitch and Glue" construction is
that it uses fewer parts and that epoxy is used to bond
and seal the parts to achieve a stronger, monocoque
(one-piece) boat. The initial construction is quicker
and easier, uses fewer parts, requires no building
molds, and all parts of the boat contribute to the
structure. And in the long term, the boat is much easier
to maintain, mostly because the structure is so very
strong and all the surfaces are carefully and completely
sealed with the same epoxy resin that was used to bond
all the parts together thus keeping moisture and water
from migrating into the dry wood. If you keep the wood
dry then paints and finishes aren't prone to cracking
and peeling off and the wood in the structure is
mummified from the possibility of rot, which requires
considerable moisture in order to flourish.
Looking back over my own development in boatbuilding,
and considering the advantages and disadvantages of the
many forms of boat construction I've used, I find my
memory foggy as to why I chose one form over another. In
the beginning, I was simply working out the differences
and identifying the problems of each form of
construction. I knew that working with natural wood
products was appealing, and I knew I wanted to use wood
products in an ecologically sound manner. A boat built
of wood has a spirit that is easy to see and feel, but
much harder to define. "Stitch and Glue" simply
produces the strongest structure, is easiest to approach for either the experienced builder or the "first
time builder" and results in a product that the builder
can be proud of for a very, very long time!
Almost all boatbuilding methods require expensive
tooling. Production fiberglass boats have their
elaborate plugs and molds. Traditional plank-on-frame or
cold-molded wooden boats require complicated building
molds. This expensive tooling can tend to stop much of
the evolution of an individual boat design. "Stitch and
Glue" construction does not bear this initial burden.
With no building molds or tooling to consider, a "Stitch
and Glue" design has a chance to constantly evolve and
improve and that's important! I believe that any design
can use refinement, and as my own design work has
evolved, I have found ways to increase the ability of
the "Stitch and Glue" boat to even more appropriately
suit its purpose and meet its owners performance
In almost any boatbuilding method, the builder must
carefully draw out, in full size, what the plans of the
boat show in small scale. Much time spent on your
knees laboring over huge painted sheets of plywood
trying to accurately draw long lines is typically not my
idea of fun. I clearly remember my confusion at
the prospect of lofting my first boat. It seemed such a
waste to spend so much time on a pursuit that didn't
seem to have much to do with boat building and I quickly
realized that even the most careful approach to the task
would still result in a fairly inaccurate result.
In "Stitch and Glue" construction, several building
basics or norms of traditional boatbuilding are altered.
First, there are no building molds required and no
complicated lofting of molds or support structures are
necessary. Second, the lofting required is not to draw a
full size picture of the lines of the boat, but to draw
a full-size picture of the parts. For a simple
V-bottomed boat, the parts required for a basic hull are
two side panels, two bottom panels, and a transom, drawn
directly onto the plywood that will be cut out and used
for those parts.
In the designs that I offer for "Stitch and Glue"
construction, I have made the conversion from
three-dimension to single-dimension for you. I have
essentially "peeled the boat", laid it out in a flat
plane, drawn a picture of it, and scaled that drawing so
it can be easily duplicated. So when you look at a
drawing of the panel projections for the boat, you are
looking at a scaled drawing of the skins or sections of
A panel-projection drawing is scaled out so that it
fits on flat sheets of plywood, the very same ones that
we will use to build the boat. If we lay out that sheet
of plywood horizontally in front of us, the left edge or
small edge is the station baseline. All stations are
measured out from that edge parallel to each other at a
fixed interval. In our example, the station space is
12", so every 12" for the length of the panel, a
straight line is drawn perpendicular to the baseline, or
long edge. When those lines are drawn and labeled, the
actual offsets can be drawn in. The bottom long edge of
the panel is our baseline, and a tape measure can be
hooked over that edge and pulled out alongside the
station line, measured and marked.
The rule in lofting is feet, inches, eighths. If a
dimension says 1-10-4, then that translates to one foot,
ten inches, and four/eighths, or one/half inch. A
dimension that say 2-4-0 is two feet, four inches, and
zero eighths and this rule is the same for all
dimensions in the panel.
Once all the points are marked onto the plywood
panel, you can connect the dots with a long, fair batten
(a long staff of dimensional wood that can be bent
around the marks you have made on the panels) and cut
the parts out. This essentially is all the lofting
needed for you to start construction and you are free to
concentrate your energy on building the boat.
At Devlin Designing Boat Builders we know wood. We
have been using wood in the marine environment for more
than 30 years and can unequivocally say that wood is the
best choice. Read on. In an era of modern
materials such as fiberglass and aluminum, you might
wonder how we could possibly make this claim. When
compared to other alternatives, wood has many
significant advantages as a construction material for
many types of marine craft.
- Better resistance to stress - Wood is the most resistant
to constant direct force... the kind like the structure
of a boat gets due to the pressure of the water on the
hull. And the faster the boat goes, the heaver the
force is. One well-known test was done on various
materials to find out how well they hold up under
constant pressure. Each material was put under
direct pressure for 1 million cycles for 30 hours at a
- Straight Fiberglass kept only 22% of original strength
- Aluminum kept 37% of original strength
- Wood with epoxy kept 64% of original strength.
- Better thermal, galvanic and acoustic characteristics -
Wood has better thermal and acoustical characteristics
than other materials so there are greatly reduced
problems with condensation on the faces of the interior
hull. Its galvanic characteristics are also ideal.
Galvanic corrosion occurs when two dissimilar materials
come in contact with each other and one causes the other
to corrode. Wood does not have this problem.
- Best aesthetics and visual experience - No one can doubt
that in terms of look and feel, you can't beat the
feeling of wood. The aesthetic characteristics of
wood and the visual experience it brings are far
superior to the synthetic experience of other types of
boats. With its warm and natural beauty, the
feeling you get when staying on board surrounded by
natural materials contributes to your joy of ownership.
- Comparable maintenance costs - Traditionally made wooden
boats typically have a high cost of maintenance. This is
not true of Devlin boats because all wooden parts of our
boats that are exposed to the sun or sea are protected
by our epoxy coating. Technically speaking,
when dry wood is protected in this manner, it maintains
all its extraordinary characteristics, practically
without aging for decades. Maintaining a Devlin boat is
no more expensive or time consuming than that of a
When compared to other materials such
as fiberglass, aluminum, or even steel, wood is actually
stronger when you look at the relationship between its
strength and its weight. This means that a
wooden boat when compared to synthetic boats of the same
size and weight, the wooden boat will have the least
weight. It also means that when compared to other
construction materials, that same wooden boat with have
the greatest strength. Bottom Line: Wood has the greatest strength per volume of weight and
that makes it highly suitable for boat building where
the material needs to be light but strong.
The Stitch and Glue Upside Down Building Sequence by Sam Devlin
The sequence for building first starts with a building jig or framework as in illustration (1a). Mark out the interval of the building bulkheads or molds on the jig's top surface. Depending on your design, they will either be bulkheads that will stay in the structure or molds that are temporary and don't stay in the finished boat, or even a combination of the two types. A centerline is also necessary to help keep everything lined up.
Now you can set your molds up on the building jig as per illustration (1b) and brace them to set vertically from the jig floor. All the waterlines should be at exactly the same measurement from the top surface of the jig and the centerlines of all the molds must be in alignment. The more careful you are during this setup stage, the easier your building project will be.
I have shown the wire frame of the hull now projected onto the jig so that you can see how the hull panels will line up with all the molds or bulkheads in illustration (2a). In illustration (2b) you can see the outline of the waterline now as it relates to the top surface of the building jig and to each of the molds or bulkheads.
Once everything is all lined up and set up properly, we are now ready to cut out the two bottom hull panels and stitch them together. In illustration (3a) you can see the two panels off the molds yet but just about ready to come together. You will stitch the two bottom panels together at the keel line or centerline of the hull face to face like the pages of a closed book. Then by opening up the panels (like opening up a book upside down) and laying them over the molds, we are ready to apply those first panels to the setup. There should be an orientation mark on the bottom panels that will show where you need to position the panels fore and aft on the molds.
Now that the bottom panels have been set into place, you are ready to stitch the lower side panels into position (see illustration 4a). Start at the bow and stitch or staple (see "New Stitch and Glue Technology") the panels along the length of the chine from the stem end to aft. You should have cut and beveled the double 45 degree angle on the inside edge of both of these panels at every edge of all of the panels except the sheer panel at the sheer edge. The double 45 degree bevel will allow the panels to lay alongside each other nicely and the molds will work wonders in keeping the panels all lined up and fair. At this point, don't fasten any of the panels to the molds but use the molds only as a framework for the panels. It's kind of like stitching together a hat of the hull panels and then putting the hat over the molds like putting a hat on your head (as in illustration (4b).
Now you can stitch or staple the two sheer panels to the stitched up parts you have already draped over the molds (as in illustration 5a and 5b). As in the lower side panels, start at the stem and work your way aft along the seam, stitching or stapling as often as it takes to keep everything lined up nicely (4-6" intervals are about right). Keeping both the sheer panels together in the bow symmetrically is very important and will give you a more fair hull.
With all the hull panels now in place and draped over the molds like a hat (as in illustration 5b), it is now time to attach the transom. The longitudinal (lengthwise) mold will assist in placing the transom at the proper angle to the hull panels (as in illustration 6a and 6b.) You can stitch the transom or fasten to the hull edges at the intersections to hold it in place and make sure to keep both sides of the hull panels in the same relationship to the transom. To explain that last statement a little better, if there were an overlap of the sheer panel on the starboard side of the boat by say a 1/4" at the transom and if the transom were in proper position and placement, then there should be the corresponding overlap on the port side of the boat. Symmetry from side to side is the rule here. Once all is done and in proper position, it is now time to tab the interior seams of the boat with thickened epoxy. This is like tack welding in metal work and will hold the panels together until the stitches or staples are removed and you can glass the exterior.
Our Book & Video
To better understand the "Stitch and Glue" boat building method, we have produced a Video/DVD "Wooden Boatbuilding with Sam Devlin" and published a book "Devlin's Boatbuilding" on the subject. These were created to help those with the desire to build their own boat.
Click on the book or video for more information.
Is a Sam Devlin designed boat right for you?
The Devlin Design Process