Wednesday 7 April 2010

Mike Griffiths (guest blogger) has a whale of a time with his canoe project

I left my account of building a stitch and glue lapstrake canoe with the inwales and outwales cut to length and ready for gluing in place. One of the challenges of this operation was clearly going to be getting a snug fit between the ends of the outwales and the pointy bit at the stem or stern. I realised that when I measured the angle for the inwale mitre I had effectively also measured the angle required for a couple of wedges that would allow me to clamp the outwale ends tightly against the hull extremities. Cutting some short wedges and trying them out showed that they would do the job so I was raring to go. All I needed was an assistant to help hold things in place while I did all the technical stuff with clamps and a mallet. Assistants proved few and far between - and then some paid project work demanded my weekends and the cold dark evenings did nothing to encourage a lot of progress.


The spring change to the clocks, the arrival of the house martins and a sudden surge in temperatures all combined to re-invigorate the project. I moved the canoe back out to one of the barns and set up to make some progress.


I marked the location of the two decks and the planned location of the "doublers" for the two seats on the inwales and then removed them and routed a curved edge onto the inside face of them both between those points. This gave a pleasing shape while retaining a square section where required for gluing the decks and fitting the seats. I also cut the doublers for the seat supports ready to be shaped to the curve of the inwale. You cant just glue them into the gunwale "sandwich" as this would result in a flat spot in the rather nice curve created by the bent oak lengths - they need to be shaped to fit.

 Routing the ends of the seat support doublers


As I mentioned, the canoe construction book suggests that an assistant would be required to glue the inwales and outwales in place. In fact, with a little care and planning you can do it yourself. I mixed some epoxy and thickened it with lots of colloidal silica to stop it running. Once it had been applied to the inwales it was pretty easy to snap these in place. A fresh batch of thick epoxy mix was then applied to an outwale and this was then offered up to the outer edge of the canoe and clamped in place. Getting the first clamp in position was the tricky part. I started from the middle of the canoe and worked outwards towards the stem and stern with a clamp placed about every 15 centimetres.


Once the clamps are in place you can spend some time making adjustments to the line and wiping away any drips or smears resulting from juggling a slippery glued outwale, a clamp and a couple of protecting plywood pads in just two hands. A sense of humour helps as you pick up one or other of these from the floor for the fifth time. I only had enough clamps to glue one side at a time but this gave me the time in between to mix up a small batch of epoxy thickened with wood dust to start filling all of those holes in the hull left by the copper wire ties. It felt re-assuring to fill in all those spots that showed daylight through the plywood - perhaps this thing will float upon the water some day.


The first side glued and clamped and the wire holes filled