A Shipwright in Training

We had a half day last Friday since the latter half of the day was spent prepping the school for hurricane Noel. As it happened, the storm tracked east of us, and all we got was a good blow (4 private boats in the sound came off their moorings and were lost) and some big waves. No one really thought we’d be hit bad, but it was good to have everything battened down.

I mentioned using the Unscrew-em’s the other day, and I described their use inaccurately… probably because I’d forgotten how to use them until the day after writing that entry. What I’d said was that you wanted the body of the screw to go up inside the hollow Unscrew-em, and cut out the surrounding wood with the tool. Not exactly… Here’s the real deal.

You actually want the tool to be the same size as the screw. When you hit the screw correctly, you grind away the outside part of the screw and barely drill away any wood around the screw. Here’s a couple of screws that I removed:

By the way, they’re just sitting on a block of wood I had handy; these aren’t the holes left over from removing screws. You can see where the tool started to grind down on the shaft of the screw on the left before it released. The one on the right was far more stubborn and didn’t come out until almost the entire screw was ground down.

Here’s what it looks like when you’ve drilled straight down on the screw. You can see how the tool will hardly take out any wood that wasn’t already pushed out by the screw.

This nice, centered hit doesn’t happen all the time by the way. More often than not, you come in at a slight angle, break the screw in the process, and end up repeating the effort a few times until you get the whole screw.

Lastly, here’s a close up of the bit. You can see how the teeth are filed to cut when the drill is in reverse.

Wow, was that exciting or what? It’s a thrill a minute around here.

Well, here’s another page turner.

I may have detailed this little operation last year, but I spent all day today doing this, and by god I’m going to write about it.

I’m back on the Whitehall this past week. We’re trying to rotate crews around between the 2 boats we’re working on to keep it interesting. Last week I laid out the plank lines for the Binder plank.

Ah, new term! The Binder is the plank just below that Sheer Plank, and it’s special because it connects to the sheer above it with a lap (as in Lapstrake planking) and to the plank below it on edge (carvel planking).

When I did my first binder, I didn’t like the look of it. It had an odd shape, a long undulating “M” shape on its top edge, and I just couldn’t believe that I’d gotten it right. I was expecting a gentle sweep or maybe an “S” shape because of the way the boat curves in and out. So, I started all over again, was extra super duper careful and this morning I got… a kinder, gentler “M” shape. Ok. Gotta trust your spiling, and that’s what I went with.

So, after cutting the plank out and planing down to the lines it was time to back it out. You may recall that planks need to rest flat on curved frames, and so you round out the inside of the plank to match the curve of the frames. This process is called “backing out.” After you round out the inside face of the plank, you curve the outside face of the plank to match the inner curve.

You start by tracing the curve at each frame onto scrap wood, marking the upper and lower edge of the plank, and then cutting along your line to get the inside and outside shape of the plank at that frame.

It’s imperative to label each template with its frame number. I also add in a designation about the plank just in case I need these again in the future. In this case P BND = Port Binder.

When you batten out your plank from the spiling, you remembered to mark the frame locations on your plank, right? Of course you did, you clever duck.

Now, transfer those frame locations onto the edge of your plank, since you’re about to plane away the inside surface of your plank and destroy all those nice references.

As long as you’re at it, you might as well mark out the edge thickness of your plank, in this case, 7/16.”

And off you go!

Here’s the start of the process. I’ve got all the little frame templates set up near the frame locations along the plank to test the hollow I’m planing into the plank.

Like this. You can see that I haven’t got a sharp enough curve yet to match this template. Warren took an old ECM plane and put a radical curve on the underside for just this type of situation.

If you take light swipes you can get pretty close to the shape you need. When you’ve gone the length of your plank, smooth things out with a scraper or sandpaper on a curved block and there you go.

Don’t forget to drill out and bung any knot holes that found their way into your plank.

This plank had a ton of backing out since the curve of the transom is so severe. To get a consistent 7/16″ thick plank, I had to start with a plank twice that thick. You can see how much material had to be removed to make the curve at the transom a few photos up. It goes to flat at the front of the boat, so you still have to remove all that extra wood there as well, only keeping it flat.

I start by hogging off big thick shavings with the scrub plane.

This is the quickest way to remove lots of wood short of using an electric power plane. And it makes such a cool ripping sound as it plows through the cedar. Like a zipper almost.

Once I get about a 1/16″ away from where I want to be, I smooth things out with the #4 smoother. Using the outside plank templates now, I check the curve with every few swipes. The process is done very much by feel. You can sense the flats and ridges as you go, and you’re constantly varying the pressure on your plane to make deeper or lighter cuts as you go.

I also mark up the board as I go to get a visual confirmation about where I’m working.

Here’s an example. After checking the curve with a template, I saw that the ends didn’t need planing, but the mid section did. I put circles where I didn’t need to hit, and a straight line to plane down.

So the process becomes simply erasing the straight line with plane cuts, and leaving the circles alone.

There you go. And here’s the fit.

Not bad.

After 8 hours, I’d made a hell of a pile of shavings. It was like an autumn leaf pile in the shop.

You could roll around in it… providing you like sharp crunchy cedar shavings all down your clothes. Mmmm.

We temporarily clamped the plank to the boat to see how it looked.

That “M” shape has completely disappeared as the plank wrapped around the curves of the boat. It fit the marks exactly and looks pretty good I think.

The plank’s not finished yet. We have to cut the gain along the top edge to fit into the sheer. You can see it here in the original (although upside down in this photo) boat. The Binder is the white plank and you can see that little thin triangular shaped gain going into the sheer.

After that, we also have to put a thin bead on the inside edge of the Binder:

THEN we can steam and attach this puppy. Oh yeah, and this boat is riveted together. That’s going to be fun fun fun.

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This entry was posted on Tuesday, November 6th, 2007 at 9:52 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.