A Shipwright in Training

The garboards got steamed up last week and Kevin’s went on without a hitch. He’s got a good eye for this stuff. I spent about 5 hours fitting and futzing to get mine to fit just right, and when I came back to it the next day it’d dried out and shifted about an inch to the left. I was all set to force it into submission, a technique called “edge setting” when we realized that my plank was about 1 1/2″ less wide than Kev’s. Ok, that’s a major problem, it totally blows the symmetry of the boat. And it looks bad too.

Here you can see both our garboards (remember? that’s the name for the first plank next to the keel. If you remembered that, gold star!) clamped down. Notice that mine (the one on the left) has a green clamp on the bottom left pushing up against a block of wood? That little clamp is exerting trememdous pressure against the plank to force it up to the keel. Kev’s just lies along the keel sweetly like it should. You can also see that Kev’s looks a little fatter near the middle of the boat… that’s the width difference.

The solution? Chuck it and start again. Dammit dammit dammit dammit dammit dammit.

The first attempt took almost 2 days from spiling to fitting. The second attempt took about 4 hours, and it fit like a glove, with no edge setting at all. AND I corrected for the width difference, so we’re back to symmetrical. Kev had his plank screwed down Monday afternoon, mine was screwed down by Tuesday lunch.

The little red marks are where we put red oxide primer on the screws as we drive them in. Yes, I know that Kev’s are cleaner looking than mine. The string you see coming out from the underside of the planks where they cross the transom is there as a defense against water. We put bedding compound where the plank meets the transom and then embed the string in that. If water infiltrates, the string will swell and block the water. Nifty, eh?

Oh, and I got a haircut. Big Time. Real barber in a real barbershop. I’m looking more like dad every day.

Ok, back to boats.

Next plank up is called the sheer. If the garboard is up against the keel, then the sheer is up against the deck, or maybe the sky, depending on the boat. This is the plank that defines the curve of the boat’s deck as you look at it from the side. It’s what makes a boat look swoopy or straight. It can be a very sexy plank. Rrrrrr.

What makes the sheer interesting is that it’s the first plank that requires backing out. Ah, term for the day: backing out. This means shaping a curve into the inside surface of the plank to make it fit up tightly against the frames. A flat plank on a curved frame will rock. Remember, a rocking plank is fine for a Stones concert on a pirate ship, but for a Beetle Cat (and any other boat really), a rocking plank means eventual water infiltration. So, you either have to flatten the frame where the plank fits it, or you have to curve the inside of the plank. We choose the latter.

To back out a plank you need to first know how much curve there is in the frame where the plank will go. That’s easy. Take a scrap of wood, hold it up to the side of the frame where the plank goes, trace the frame’s curve in the middle of your scrap, and cut that line on the bandsaw. That way you get 2 curves really, one for each side of the scrap that you just cut. That gives you an idea about not only the shape of the inside of the plank where it meets the frame, but also of the outside of the plank once it’s all finished and rounded over. Here’s the templates for frame 11, sheer plank (11 S).

So, you do this for every frame. You get lots of templates. Here they are laid up next to my sheer plank (already spiled, cut out and planed to shape… it’s getting easier now).

So how do you cut out this curved inside surface? With a backing out plane of course! The very ones that we built earlier. So now, you take a few lengthwise swipes with your plane along the inside edge of the plank, and check the curve you just made with the little templates. The backing out plane has a slightly rounded bottom to accomplish this task.

The blade is curved to match the bottom. Yep, we do all that ourselves. See the little purple star up on the plane blade at the top? That means, “good plane” in Jen’s grading system.
The plane cut like a dream, mostly because I took a lot of time to really sharpen it up. A sharp plane on cedar is just the easiest planing job on the planet. You get piles of curly little shavings.

When the underside is backed out and matching your templates nicely, it’s time to flip the plank and plane the initial curve on the outside. Take your hand, stretch your fingers out straight like you’re going to make a little salute, curve your fingers down about a half inch. That’s an exaggerated version of what you’re making the plank look like in cross section.

The fun part about rounding the outside of the plank is that you get to go from end to end in one long pass of the plane. This makes for long beautiful shavings.

If you get tool catalogs or woodworking magazines, you know that the better ones tempt woodworkers with promises of planes that produce long, full-width, gossamer shavings when you plane. This is called tool porn. Well, here’s a long, not quite gossamer shaving, and I got to make them over and over when planing this plank. I’m here to tell you, it’s just as satisfying as the catalogs imply it is.

So, the sheer plank went in the steamer and then onto the boat, and tomorrow I’ll fasten it onto the frames. You can see it clamped on the lower left side of the boat.

Jen wanted us to have 4 planks (2 / side) on the boat by the 15th,
we’ll have a lot more than that done by the end of this week. It’s nice to be moving along so well again.

This entry was posted on Wednesday, December 6th, 2006 at 9:01 pm and is filed under Classes. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.