o pEd

Where s h o u l d w o o d e n b o a t s g o ?

After master boatbuilder Jack Chippendale considered the future of wooden boatbuilding in W76, he and we received equally considered responses – but none from wooden boatbuilders.He and we persevere...

May I begin by thanking those who responded to my thoughts on 'Environmentally Friendly Boatbuilding' in the Op-Ed in W76. In particular, I am grateful to Peter Howe of the Eco-Boat Project, Bill Street of the PEFC, Yvonne Green of the Boat Building Academy and amateur boatbuilders Philip Archer and Martin Sutor for taking the issue seriously and continuing the discussion in W77 and W78. It matters not whether they agree with me, what matters is that a debate has started, one in which we may yet persuade professional wooden boatbuilders to participate too. Let me try...

When I commenced my boatbuilding career in 1938, marine plywood as we now know it did not exist and when in 1947 I ventured to strike out on my own, boatbuilding methods had hardly changed. During the war, we had witnessed the appearance of the new synthetic resin adhesives but these had yet to make an impart. That came later. Our boats, therefore, were very near the 'all solid wood boat' which Bill Street considers to be the most environmentally-friendly. However, the percentage of waste incurred when cutting shaped planks from logs sawn 'through and through' was truly astonishing. And we were also using metals such as copper, the extraction and production of which has also significant environmental impacts.

With this in mind and accepting entirely the requirement to use wood from sustainably managed sources, I still suggest that the least wasteful method of timber conversion and use would be rotary-cut constructional veneer – the whole log is held in what is effectively a giant lathe and veneers are peeled off like sharpening a pencil; Ed. With one exception, the many cold moulded boats we made were built before the introduction of epoxy resins; the adhesive we used then was resorcinol. I have since been concerned to discover what the different environmental impacts of resorcinol, epoxies and other resins might be but so far without success.

At which point, I should state that 'I use epoxy'. I believe it to be an excellent adhesive and tool when used intelligently. However, I warn students that it can and does mask poor boatbuilding. Unlike epoxy, resorcinol is not a gapfilling resin and therefore requires very close contact between gluing faces and a necessarily higher degree of care in work. Close contact also means that much less glue is required.

None of those cold moulded boats we built in the late 50s and early 60s had their hulls sheathed and some were in use up to a few years ago. The timber we used had, I believe been the least wastefully converted and the minimum amount of resin had been required.

Thus, I'm delighted to endorse the comments on cold moulding in W78 by Martin Sutor, whom I remember from one of my courses at the Boat Building Academy in Lyme Regis. I would only add that his comments regarding the size of hull using two skins and hence strength relative to hull thickness seem a little conservative. The 20' (6m) Uffa Fox designed Flying 15 keelboats we built in the 60s only required two 1/8" (3mm) skins, yet their hulls were strong enough and none were sheathed.

Some still advocate the environmental merits of stripplank construction, in which planks of very small section are edge-glued together, saying that since short lengths can be utilised the method is less wasteful of timber. However, every sawcut wastes timber and creating small planks will require many more sawcuts, each of which will later need resin to be glued back together again! Worse still, since the strip planked hull has no integral strength, it requires epoxy/glass sheathing, both inside and out.

Compared to strip-planking, cold moulding is surely by far the more environmentally sustainable. But to be fair, many of the arguments in its favour can also apply to marine plywood made from rotary-cut veneer. Sound but unattractive timber with knots below a specified size, which would nonetheless have to be discarded in both our traditional 'all-wood' construction and in modern strip-planked boatbuilding, can be satisfactorily used in the core veneers of plywood. While again I feel there is a need for boatbuilders to enquire more closely abot the environmental credentials of the various adhesives employed in different grades and brands of plywood, I would suggest that, in quantity at least, its impact must be less compared to epoxy/glass strip planking.

I would suggest, therefore, that glued clinker hulls made from top quality plywood and requiring almost no metal fastenings – and not incurring the cutting waste of the traditionally-planked built clinker or carvel boat – should sit alongside cold-moulding at the top of the environmental sustainablity rankings for wooden boat construction.

www.watercraft-magazine.com