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By Ross Lillistone - Esk, Queensland - Australia


I Do Stitch-and-Glue

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For many years now, I’ve been keeping a dark secret. But now the time has come for me to confess – I like Stitch-and-Glue as a building method for boats! There, I’ve said it!

Now there have always been people around who do things for sensible, practical engineering reasons. These people found out that stitch-and-glue made sense fifty years ago, and they used it for the simple reason that it worked. However, there are other types (like me) who worry too much about what people think, and who have avoided the taped-seam joint like the plague.

For me, the traditional look of clinker (lapstrake) construction had, and still does have, an attraction which is difficult to escape. I knew that if I built a boat that way, she would be considered a ‘proper’ boat by the traditionalists, and my fragile ego would remain intact.

Other construction methods which I thought I could use and still be thought of as a ‘true-wooden-boat-person’ included plywood planking over stringers and frames, batten-seam, strip planking, diagonal planking, and strip-diagonal, to name a few. With this in mind I stumbled along a boatbuilding path stretching nearly forty years, and was generally reasonably happy with what I turned out.

What brought me face-to-face with the prospect of actually building a stitch-and-glue boat was my introduction to the work of the late Philip C. Bolger in about 1979. In his book ‘Small Boats’, Phil endorsed the method, and indicated that he had been using it since the early sixties.

Now, I knew quite well that Jack Holt had been designing stitch-and-glue boats for many years, but it wasn’t until I started reading Phil Bolger that I took the method seriously. Subsequently, I came across more and more stitch-and-glue designs from people whose judgment I trusted, and finally, in about 1985, I built a stitch-and-glue boat – a Bolger ‘Nymph’. This boat was everything the literature claimed – light, clean, shapely, and strong – and so very simple to construct and maintain.

Bolger ‘Nymph’

In the year 2000, I left a twenty-five year career to follow my own star, beginning a ten year odyssey as a boatbuilder working professionally. In that time, I’ve built about fifty-three boats, and repaired many others. This full-time exposure to small timber boats has given me the opportunity to gain first-hand experience of a wide range of building methods - from the point-of-view of ease of construction, structural strength, maintenance, repair, durability, economy, and so on.

Each building method lends itself to particular designs, and certain designs and construction methods are mutually-exclusive. For a complex round-bilged hull it is not possible to use stitch-and-glue (although you can get close with knowledgeable design), and for such hulls I prefer the glued-lapstrake (clinker) method.

One notable building project we undertook was a Phil Bolger ‘Harbinger’, which is a 15ft x 7ft 1” Catboat of the New York model. She has a most spectacularly shaped hull, with sweeping curves which change from convex to concave in all directions. Originally, this boat was designed to be built using plank-on-frame carvel construction, but the owners wanted to be able to store her out of water on a trailer, so the carvel method was ruled out (a carvel boat should be kept wet in order to prevent the plank seams opening).

At the time I was much influenced by the work of the Brooklin Boatyard in Maine, and I elected to build ‘Harbinger’ using the strip-diagonal method, which promised to be strong, light, tolerant of trailering, and suitable for the complex hull shape. In April 2002 I wrote to Phil Bolger to obtain his permission to alter the construction and he replied saying, “The construction you propose is the best for the purpose barring expense. Plywood lapstrake would be the alternative. The ‘Harbinger’ hull shape is ideal for either.” In a later response he also said, “Harbinger looks very good, though the amount of work in that construction is scary….”

Harbinger

Phil was correct about the amount of labour in the ‘Harbinger’ job! During construction we put in, and removed, eighteen thousand stainless steel staples in the diagonally-planked layers – and that was after having built and faired the internal strip-planked section of the hull. These days I would use vacuum-bagging techniques, but even so, it would be a very big job for a small shop.

Most of the boats I’ve built have been done using the glued-lapstrake (clinker) method, and it is an exceptionally elegant way of producing a shapely hull. However, it does have a few shortcomings, the most important of which is the vulnerability to damage of the edge-grain on the plank laps i.e. the stepped edges of the overlapping planks. Other problems include the time required to build the strong-back and molds, and the need to spile (determine the shape of) each pair of planks. The final limitation is the need for very high-quality plywood, as the strength of the hull is largely determined by the glue bonds between each pair of plank faces, and between the two outermost veneers of the plywood.

Bolger Hope

Now, to get back to the point of the article – a stitch-and-glue hull can be built from panels of plywood which have been marked directly onto the plywood sheets, and cut-out using a jigsaw or similar. There is no need for spiling of plank shapes, and most importantly, there is no need for any sort of strongback or mold – as long as the designer has produced accurate panel expansion drawings, and as long as the parts are marked and cut accurately.

Another major saving of time, labour, and money, is brought about by the absence of most of the normal longitudinal framing such as chine logs and sheer clamps (this is a generalisation, dependent on the particular design). Chine logs which don’t exist will never need to be cut and beveled, they can’t rot, and they have zero weight!

Stitch n Glue

If a stitch-and-glue boat is correctly designed and accurately cut, she can only have one shape when put together – think of peeling a banana, removing the banana flesh, and then re-assembling the skin – the shape of the assembled skin will be the same as it was before being peeled. That is why you can get away without a strongback and molds when building a stitch-and-glue boat – it is the two-dimensional shape of the planks (or skin) which determine the three-dimensional shape of the finished boat. Normally, you do not need an elaborate mold.

Stitching the hull

Over the millennia there have been plenty of other examples of boatbuilding which can be done without a mold – Viking Ships, Birch Bark Canoes, Flat-Iron Skiffs, Pirogues, to name a few. But for our times, the stitch-and-glue method presents some extra advantages. For example, the existence of CNC cutting facilities allows the rapid and economical production of pre-cut kits – something for which the stitch-and-glue method is uncommonly well suited.

I mentioned earlier in this article that the edge grain of the plywood is particularly prone to damage and water soakage. Stitch-and-glue boats have this vulnerable edge grain buried in thickened epoxy and covered with epoxy/glass sheathing. Not only that, but the large surface area of the glass covering of all of the joints means that stresses are dissipated into the structure quite gently and evenly.

Taping the fillets

Space limitations prevent me from writing as much as I would like, so those who are interested should have a good read of some of Jim Michalak’s and Dynamite Payson’s books, and especially Sam Devlin’s excellent text called, Devlin’s Boatbuilding, which is the best one on the subject that I have found.

You can also find plenty of free photos showing the process on my website, www.baysidewoodenboats.com.au , under the buttons titled, ‘First Mate Photos’ and ‘Flint Photos’.

Flint

Stitch-and-glue can produce a light, strong, and shapely hull of the highest quality. You don’t have to be an expert woodworker or a qualified boat-builder – but you must follow the rules and pay great attention to detail.

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For photos and regular updates, please visit Ross' website at
http://www.baysidewoodenboats.com.au/

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