Fine Wood Water Craft Designer, Boat Builder Canoes and Kayaks

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About Eskimo Tom Artist, Designer, Boat Builder Canoes and Kayaks
About Eskimo Tom: Artist, Designer, Boat Builder Canoes and Kayaks

What Is Stitch and Glue?

The term describes a process of joining planks lengthwise edge to edge using wire or plastic ties called "stitches." Planks are cut from thin marine plywood and stitches hold planks together temporarily for gluing then fiber glassing. Fiberglassing and finishing is no different than completing a wood strip boat.

Plank patterns are first designed in 3 dimensions to meet the intended use. The "expanded" design is used to develop plank patterns which are then "flattened" to cut out od marine plywood for the hull. Scale models can be made from paper to help clients visualize the final shape prior to final construction.

Once planks are wired together, the seams are filled with a thickened epoxy slurry. Once cured, the wires are removed, all remaining seams and holes are filled and the hull is carefully sanded in preparation of fiber glassing and final finishing.

After the glass is applied, the boat is finished in a traditional manner with trim, gunwales, thwarts, seats shear clamps, bulkheads, deck, coaming, hatches, etc. It is a well established boat building method for the do it yourself builder and is also used by some commercial concerns to create significantly larger craft.

The skin of the craft becomes a load bearing structure similar in construction of an airplane’s monocoque fuselage. Monocoque construction means the outer skin carries all or a major part of the stresses. This results in a lighter, stiffer boat. It is an ideal technique for other small wood watercraft including yacht tenders, prams, pulling boats, sailing dinghies, etc.

Material Strength

Working six or seven planks per side in an attempt to get sweeter lines, one might consider glued lap construction exchanging all the drilling and wiring for building a form and clamping. Folks most interested in a round or smooth bottom hull, the preferred method is strip building.

It is conceivable that your life may depend on the strength of your boat and cutting costs in materials is the wrong place to save money. Also when you add up all the time and materials used to build your boat, and you put a realistic value on your time say $20.00 hour, you will find that even the best plywood will constitute a small fraction of the final cost. Get the good stuff (British Standard 1088, 4MM ) you’re worth it.

In thinner dimensions (3MM and 4MM), quality marine plywood is much stronger than conventional planking of the same thickness. This is due to the cross wise lamination of veneers and thickness can be proportionally reduced. Plywood thickness has its limitations with respect to the minimum bending radius. It is feasible to cut the individual planks of a lap strake hull out of plywood sheets.

I have found that five planks per side for a total of ten on a canoe is not unreasonable for this technique. However when attempting to get a more rounded shape by doubling the number of planks, complexity increases as the amount of cutting, drilling, gluing and filling holes is increased significantly making the stitch and glue method less attractive or appropriate.

Benefits of Stitch and Glue Boat Building

  • DESIGN:
  • Smooth skin
  • Very Light Weight
  • FAST:
  • Less milling than wood strip construction
  • Only 2-3 station forms to be cut
  • No Strongback Required
  • SAVINGS:
  • Efficient use of material
  • Less wood turns to sawdust, unlike strip constuction
  • No Strongback Required

The stitch and glue method offers considerable savings of time and materials.

The skin of the craft becomes a load bearing structure similar in construction of an airplane’s monocoque fuselage. Monocoque construction means the outer skin carries all or a major part of the stresses. This results in a lighter, stiffer boat. It is an ideal technique for other small wood watercraft including yacht tenders, prams, pulling boats, sailing dinghies, etc.

Scaling up lines plans for cutting stitch and glue boats
Scaling up lines plans for cutting stitch and glue boats

Construction Overview

The photo above shows plank outlines being scaled up from plans at each station, typically every 12 inches.

Once drawn to full scale from the plans, they are cut out using a sabre style saw. I cut two sheets at once to get planks for both sides.

Once planks are initially wired together, time is devoted to careful alignment to get the hulls shape correct as intended.

I will generally devote a full day to this step, leaving and coming back, tightening and loosening wires until everything looks ship shape.

Next comes dabs of thickened epoxy carefully tabbed on the seams between the wires. When cured this will hold the shape of the hull while wires are removed and seams filled. I always mask off the planks prior to this stage.

Remaining seams are filled with thick epoxy slurry, all remaining seams and holes are filled and the hull is carefully sanded in preparation of fiber glassing and final finishing.

After the glass is applied, the boat is finished in a traditional manner with trim, gunwales, thwarts, seats shear clamps, bulkheads, deck, coaming, hatches, etc.

Stitch and Glue is a well established boat building method for the do it yourself builder. It is used by some commercial concerns to create significantly larger craft.


About Eskimo Tom Artist, Designer, Boat Builder Canoes and Kayaks
About Eskimo Tom: Artist, Designer, Boat Builder Canoes and Kayaks

A Plywood Primer for Small Boat Builders

The quality of Douglas Fir based marine ply (typically "AC" class), is better suited to large craft, not canoes or kayaks. Douglas Fir marine ply is better suited to larger craft than canoes or kayaks. Boats like those designed by Philip Bolger or Jim Michalak.

The thin plywood found in big box home repair stores is typically luan, a relatively thick center core covered by two very thin exterior skins. The inner core of luan ply is very poor quality and the glue used to bond the plys will not stand the test of time.

In Minnesota and many rural areas in the flyover zone, high quality marine plywood is a rarity and difficult to find.

Your can google okume marine plywood identify your nearest sources. If you are on the coasts, you are in luck. In the center of the country, some regional lumber yards may stock it or perhaps have it shipped to them for you to pick up.

Why Marine Plywood?

BS-1088 is the highest quality marine ply with a defect free core and both faces using a solid "A" surface. By "A" surface, we mean it looks great and will be defect free. A majority of this marine plywood is made from the Okoume (Acuomea Kleinea) tree harvested in the tropical forests of the Congo Basin, primarily in the African state of Gabon. Virtually all this marine plywood is manufactured Greece, France, Israel and Asia.

There is also a BS6566 standard which is less species specific and is more permissive so the surface may show skin defects on one or both faces. I have no experience with this grade or with any grade of marine plywood manufactured in the USA. Without question, for this kind of work, a small boat, where the materials call for 2 or 3 sheets for hull, I'd plan on okoume.

Always check the ply when ordering to make sure you get what you ordered. Just because it is labeled BS 1088 does not guarantee it is in fact 1088.