Tuesday, December 12, 2006

Building a Canoe


I’m not going to go through the whole process of building the boat you can learn about that by buying the book Build Your Own Canoe. Instead I will just outline the process and give a few tips for those who want to build one themselves.

What You Need
I started with completely inadequate tools, no experience and no real suitable workspace. This meant a lot of borrowing (thanks Jono), a bit of delay and some tried patience around the house (sorry chaps). However, if you don’t want to lose friends, fingers or your mind this is what you will need.

- variable speed jigsaw
- plane
- tenon saw
- spoke shave
- hammer
- four g-cramps
- face masks
- rubber gloves
- some sort of workbench
- power or hand drill (with various bits)
- dry, well ventilated workspace 6+metres long
- at least one friend

The wood, paint and adhesives materials will cost over £150 and can be picked up at any good lumberyard and/or DIY store. You might have a problem getting the glass fibre tape. If you are in the UK the chandlers in Covent Garden (London) have some. If you can't get it you can cut some from the sheets you get in car bodywork repair (WEAR A MASK & GLOVES WHILE YOU CUT IT- STUPID!) Don’t skimp on the plywood, it must be good marine quality ply - the cheap stuff may delaminate.

Cutting The Hull Panels
The book gives you fairly exact instructions about cutting out the basic shapes. However, as Gareth’s old woodwork teacher used to say “measure twice and cut once” care at this stage can prevent you owning a lot of expensive firewood. Realistically you are going to be cutting the panels out with an electric jigsaw. If you have never used a jigsaw before remember:

- use a small toothed plywood blade
- cut away from your hands
- make sure the wood is held down firmly and clear of the workbench (coffee table in my case)

Before you cut the curved sections from your plywood, mark all the measurement points you can and bend one of the ‘wangy’ bits on gunwale wood so that it touches all these known points. Then, by clamping one end in place you can use it to mark a good, elegant curved line. Cut as closely to the line as possible but if you do deviate slightly don’t worry. There is plenty of slack in the design to recover the problem later - don’t be tempted to go back and even up the edges.

Joining The Hull Panels
Scarf jointing is about the most technical job you’ll have to do in the build. Chris and Jono were invaluable in working out just how to do this. Essentially it involves planeing one edge of each of the twelve main ply sheets to a shallow angle. This allows them to be inverted over eachother and joined (making 6 longer sections) using glue and brass panel pins.

Once the panels are finished they are joined by drilling 2mm holes along the joining edges and ‘stitching’ the boat together using strong fishing line. This isn’t as easy as it sounds because the forces that build up towards the bow and stern of the bottom panels can be quite significant. Lots of swearing and mole-gripping may be required (you can’t use g-gramps on converging surfaces).

Now you can stand back and look at your boat (it will look monstrous) and begin to think about making it waterproof. The joints between the panels are covered with epoxy and glass-fibre tape (please, please, please wear a mask and gloves and open all doors and windows). This can take a while and it can also be messy. Remember that the epoxy resin will drip between the panels and out onto the floor. Doing this in the living room required a lot of newspaper, you might do well to find a more sensible location.

Fitting Out The Hull
Once the hull is basically sound the end-knees and decks are fitted. These triangular sections at each gunwale end of the boat make it start to look viable as a craft but the major transformation comes with fitting the gunwales themselves. I made ‘open’ gunwales that look much superior to the plain one. They allow water to be poured out of the boat easily and give it a much more professional finish. (I tried to describe this but the pictures are more eloquent.)

The instructions for fitting the seats are at best vague. It suggests the option of hanging them from the gunwales but this seemed pretty much impossible with open gunwales. As a result I made a half arsed attempt to glue and pin them in. This design option was tested to destruction by Dave's huge arse. Since these pictures were taken the seats have been coach-bolted through the hull.

Finishing
Finishing involves a lot of sanding, varnishing and painting but it makes the difference between a good and a bad looking boat. There will be large drips of epoxy on the outside of the boat (where it has run through). These drips are very hard and, if you intend to plane them off, use an old plane - it ruined mine. I recommend painting the bottom two panels (which are mostly under the water) and varnishing the inside and the outside of the top panels. Remember to rub any pencil marks off the wood before varnishing.

I made my own paddles too but (since Chris has managed to break them) I’m perhaps not best placed to advise on this.

The finished boat, "Sniffer" looks lovely and, despite the fact that it is slightly bent at one end, I love it.

Gary

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