Building the Devlin Oarling dory
It all begins with a trip to the local supplier of marine plywood. When I visited a couple months ago, quarter inch meranti was around $33 a board—now it's up to $50. A few sheets for the sides and a sheet of three-eighths for the bottom, a board of spruce for the sweeps, mahogany for the seats, and various other bits for the next boat put a $500 dent on the credit card: Boatbuilding requires a very Buddhist point of view on money.
The bottom panel is exactly two feet wide, and the side panels are less than that, so I ripped all the ply in half to make it easier to work with. After that, it's scarfing time: To make the long panels, you glue them together across a long sloping joint. Stack the boards together and stagger them out at a 1:8 slope. Plane away as much as you can, then sand down to a flat surface to build the slope. The layers in the plywood make a handy contour map showing where to grind away. Cover the mating surfaces in glue, turn one over and try to make them look like a single piece of plywood.
It turns out those handy bench-and-chest units I built out of scrap aren't so useful as chests when they're employed as benches. It seems like every time I need something it's inside the bench with a bunch of plywood stacked on top of it.
The three-eighths ply has really colorful layers:
After lining the boards up carefully, I drove finishing nails through the stack to keep them from shifting when I put weight on top. (The weight here isn't actually kitty litter, but leftover dry cement from building hypertufa planters last summer. Handy plastic bin, though.)
The nails were longer than the stack of boards, so I should be able to pop them up from underneath and pull them out when the glue has set, right? Except I forgot to add the base I stacked the plywood onto, so there's no slack left to hammer back up: I had to pry the boards off and whack the nails out while trying to hold a stack of wobbly 2'x16' panels upright. Still, these were by far the cleanest scarf joints I've made so to date.
At this point, I wanted to dig into some of the other wood I'd bought so I ripped the spruce down to square sticks, got out my new best friend the block plane and went to town making shavings.
One handle for one oar. The bevels are a nice detail, I think:
The next step is lofting the panels. I don't have any pictures because it's just drawing lines on plywood, and lines on plywood don't show up well in photos. The plans give you a set of coordinates; plot those points out on the plywood, draw smooth curves between the points, and there's your panels. This part is very satisfying to obsessive math types like myself. Next, you cut. Previously I've tried to run the jigsaw right down the line, and wound up with a wobbly cut with a slop of an eighth inch on either side; this time it occurred to me to give a bit of leeway and shave it down to the line with my new best friend. Also, this way I can double up the side panels and carve them to exactly the same shape.
When the panels are cut, you bend the panels around the seams, drill holes along the seams at matching points, stitch them together with baling wire, and bring those two dimensions up into the third: suddenly, it looks like a boat! Here's the before and after:
If you're as picky as I am, you might notice that the seams don't quite line up. If I'd been paying attention, I would have turned one of the panels over before lofting so the scarf joints would be symmetric across the centerline. Symmetry isn't just pretty, it helps a boat go in a straight line. Considering all the other little screw-ups I'm bound to make building this boat, though, I'm sure this small one will be lost in the wash.
Here's a profile panorama. The shed's too cluttered (I was about to say small, but it's 800 square feet) to get it all in one shot:
After stitching, you glue. Stitch and glue. Yes.
Instead of putting fillets—runs of epoxy thickened with wood pulp, laid along the seams—in now and trying to pull the stitches out later (some people use a car battery and jumper cables to heat up the wire and pull it out!), I wanted to try tabbing, laying glue between the stitches to fillet over later. Once that's set up and everything's stuck together, just pull the wires and lay in the fillets. It worked great. It's really cool to leave a floppy wire-and-plywood mess at night and come back in the morning to a more or less rigid hull.
Before gluing I spent a lot of time making sure everything was level and square. On the canoe I built before this I didn't worry so much, and I came out with an obvious twist in the hull. It didn't seem to affect the performance at all, but you can't help notice it if you know it's there and it's disappointing to spend a lot of time building something and have it come out not quite right. The art of boatbuilding seems to be managing the tradeoff between attention to detail and driving yourself insane.
This is the fun part of boatbuilding where every little job feels like a huge step forward. I know that later on the apparent return on time investment is going to be much, much less, so I enjoy it while it lasts.
|All content copyright Dave Hayden|